WO2005036620A1 - Exposure method, exposure device, and device manufacturing method - Google Patents

Abstract

An exposure device includes: a first control system (92) having a controller (56) for controlling a first stage according to its position deviation and an ILC controller (58) for acquiring a correction value group for bringing the position deviation gradually to zero by repetition learning; a second control system (94) having a controller (66) for controlling a second stage according to its position deviation and an ILC controller (68) for acquiring a correction value group for bringing the position deviation gradually to zero by repetion learning, wherein an instruction value based on the current position of the first stage is given when the both stages are moved in synchronization; and a control unit (80) for successively storing a correction value group acquired by the ILC controller connected to the corresponding control system and successively inputting the correction value group acquired in advance by the ILC controller as a correction value of the position deviation, to a control system not connected to the corresponding ILC controller.

Description

 Specification

 Exposure method, exposure apparatus, and device manufacturing method

 Technical field

 The present invention relates to an exposure method, an exposure apparatus, and a device manufacturing method, and more particularly, to a lithographic apparatus for manufacturing an electronic device such as a semiconductor element and a liquid crystal display element.

The present invention relates to an exposure method and an exposure apparatus, and a device manufacturing method using the exposure method in a lithographic process.

 Background art

 [0002] At a semiconductor device manufacturing site, a mask on which a circuit pattern has been drawn using an ultraviolet pulse laser beam having a wavelength of 248 nm from a KrF excimer laser or an ultraviolet pulse laser beam having a wavelength of 193 nm from an ArF excimer laser as illumination light. Alternatively, a reticle (hereinafter collectively referred to as a “reticle”) and a wafer as a photosensitive object are one-dimensionally scanned relative to a projection field of view of a reduction projection optical system, so that a reticle is formed within one shot area on the wafer. A step-and-scan type scanning exposure apparatus (also called a scanner or a scanning stepper), which repeats a scanning exposure operation for transferring the entire circuit pattern and a stepping operation between shot areas, is becoming mainstream. According to this type of scanning 'stepper, it is possible to mass produce circuit devices with a density of 256M (mega) bits D-RAM and a minimum line width of 0.25 μm. Further, an exposure apparatus for mass-producing the next generation circuit device of 1 G (giga) bits or more is being developed.

[0003] In a step-and-scan type scanning exposure apparatus, a reticle (reticle stage) and a wafer (wafer stage) are moved in a scanning direction while maintaining a speed ratio corresponding to the projection magnification of a projection optical system. Exposure is performed while moving synchronously, and the pattern formed on the reticle is transferred to a plurality of shot areas on the wafer. For this reason, in a scanning type exposure apparatus, a dynamic factor such as a synchronization error between a reticle stage and a wafer stage during scanning exposure causes a positional shift (or distortion) of a pattern image transferred onto a wafer and a change in resolution. It becomes a factor such as deterioration. Therefore, in a scanning exposure apparatus, it is desirable to minimize the synchronization error between the two stages during scanning exposure as much as possible. Various proposals have been made to reduce the period error (for example, see Patent Document 1).

[0004] However, most of the techniques related to synchronous error reduction that have been proposed so far reduce a synchronous error by focusing on factors common to scanning exposure apparatuses in general, and at least general apparatuses of the same model. For this reason, the performance of devices to be manufactured is different for each semiconductor maker (that is, the user of the exposure apparatus). Today, it is becoming difficult to sufficiently cope with the technologies proposed so far. . On the other hand, high integration of semiconductor devices and miniaturization of device rules (practical minimum line width) are expected to progress further in the future.

[0005] Against this background, iterative learning control (Iterative Learning Control) has recently attracted attention as a technique that can reduce the synchronization error between the reticle stage and the wafer stage of a scanning exposure apparatus.

 In a scanning exposure apparatus, when sequentially transferring a reticle pattern to a plurality of shot areas on a wafer, in order to improve throughput, the reticle is usually alternately scanned (reciprocally scanned) so that the next shot is sequentially performed. The region is exposed. For this reason, after the transfer of the reticle pattern to one shot area is completed, at the time of prescanning before the start of exposure (acceleration time up to the target speed (scanning speed at the time of exposure) + after the end of acceleration, the speed is within a predetermined error range). An operation (overscan) is required in which the reticle is further moved from the end of exposure by the same distance as the movement distance (settling time until the target speed converges) to return the reticle to the scan start position for the next shot area exposure. Corresponding to this, in addition to the operation of stepping the wafer by one shot area in the non-scanning direction to expose the next shot area (another shot area adjacent to the one shot area in the non-scanning direction). A movement operation between shot areas including a movement in the scanning direction is required.

 [0007] When the iterative learning control is employed to reduce a synchronization error between a reticle stage (mask stage) and a wafer stage (object stage) of a scanning exposure apparatus, the above-described movement between shot areas is performed. It is important to consider the effects of

 Patent Document 1: JP-A-10-270343

 Disclosure of the invention

Problems the invention is trying to solve The present invention has been made under the circumstances described above, and a first object of the present invention is to reduce a synchronization error between a mask unique to each exposure apparatus and a photosensitive object, and form the mask on a mask. It is an object of the present invention to provide an exposure method and an exposure apparatus capable of accurately transferring a pattern on a photosensitive object.

 [0010] A second object of the present invention is to transfer a pattern to each partitioned area on a photosensitive object with high precision while suppressing displacement of the object stage in the non-scanning direction due to movement between the partitioned areas. An object of the present invention is to provide an exposure method that enables the above.

 [0011] A third object of the present invention is to provide an exposure method and an exposure apparatus that can control an object stage according to operating conditions while correcting the position of the object stage.

 A fourth object of the present invention is to provide an exposure apparatus that can improve the effect of the repetitive learning control when the repetitive learning control is applied to an object stage, a mask stage, or the like.

 Means for solving the problem

 According to a first aspect of the present invention, a mask stage for holding a mask and an object stage for holding a photosensitive object are synchronously moved in a predetermined scanning direction, and a pattern formed on the mask is formed. Is transferred onto the photosensitive object, wherein the mask stage and the mask stage are considered in consideration of a first correction value group that makes a position deviation, which is a difference between a target position of the object stage and its current position, gradually approach zero. While synchronously moving the object stage, a second group of correction values for repeating a position deviation, which is a difference between a target position of the mask stage according to a current position of the object stage and the current position, to zero, is repeated. A first step obtained by learning control; while correcting the positions of the object stage and the mask stage using the first correction value group and the second correction value group, respectively, A first exposure method comprising; synchronously moving the object stage to the scanning direction, the pattern formed on the mask and the second step of transferring onto the photosensitive object.

[0014] According to this, prior to actual exposure, a first correction value group for ascending a position deviation, which is a difference between a target position of the object stage and its current position, to zero (this is an experimental value, The mask stage and the object stage are determined in consideration of A second group of correction values for ascending the position deviation, which is the difference between the target position of the mask stage corresponding to the current position of the object stage and the current position, to zero while repeating the synchronous movement of 1 step).

 [0015] Then, at the time of actual exposure, the first correction value group and the second correction value group are used V to correct the positions of the object stage and the mask stage, respectively. Are synchronously moved in the scanning direction, and the pattern formed on the mask is transferred onto the photosensitive object (second step). That is, at the time of scanning exposure, a first correction value group for ascending the position deviation, which is the difference between the target position of the object stage and its current position, to zero, and the target position of the mask stage corresponding to the current position of the object stage. Since the positions of the object stage and the mask stage are corrected using the second correction value group for ascending the position deviation, which is the difference from the current position, to zero, the synchronization error between the two stages is effectively reduced. The scanning exposure is performed in a state where the temperature is reduced. In particular, since the second correction value group for making the tracking error of the mask stage with respect to the object stage asymptotic to zero is obtained by the repetitive learning control performed in advance, the exposure method of the present invention The synchronization error between the mask and the photosensitive object, which is specific to the exposure apparatus to be applied, can be reliably reduced, and the pattern formed on the mask can be accurately transferred onto the photosensitive object.

 In this case, prior to the first step, a third step of repeatedly obtaining the first correction value group by learning control while moving the object stage in the same manner as the first step is further described. Can be included.

 [0017] In the first step, repetitive learning control for obtaining the first group of correction values may be performed in parallel during the synchronous movement. That is, prior to exposure, not only the second correction value group but also the first correction value group can be repeatedly acquired by learning control while the mask stage and the object stage are synchronously moved.

According to a second aspect of the present invention, in a second aspect, an object stage holding a photosensitive object is moved in a predetermined scanning direction, and a plurality of divided areas on the photosensitive object are exposed to each other, and An exposure method for forming a pattern, similar to a moving operation between divided areas performed between an exposure for one divided area and an exposure for the next divided area prior to an actual exposure operation. Both in the scanning direction and in the non-scanning direction orthogonal thereto A first group of correction values for moving the object stage along a predetermined intersecting path and asymptotically reducing the positional deviation, which is the difference between the target position of the object stage in the non-scanning direction and its current position, to zero. A step of repeatedly performing learning control on the object stage; performing a movement operation between the partitioned areas while correcting the position of the object stage in the non-scanning direction in consideration of the first correction value group; A second step of performing the exposure by moving the object stage in the scanning direction before and after the movement operation between the regions, and forming the pattern in each of the divided regions on the photosensitive object. This is an exposure method.

[0019] According to this, prior to the actual exposure operation, the scanning direction and the scanning direction are set in the same manner as during the movement operation between the divided areas performed between the exposure for one divided area and the exposure for the next divided area. While moving the object stage along a predetermined path that intersects both in the non-scanning direction orthogonal to the direction, the position deviation, which is the difference between the target position of the object stage in the non-scanning direction and its current position, is asymptotically reduced to zero. The first correction value group is obtained by iterative learning control (first step). The first correction value group obtained in this case is different from the correction value group obtained by repetitive learning control in which the object stage is moved only in the non-scanning direction, and the movement of the object stage in the scanning direction is in the non-scanning direction. The effect on the movement of the object stage is taken into account as a result, and a correction value group closer to the movement operation between the actual partitioned areas of the object stage is obtained. Further, since the first correction value group is obtained by the repetitive learning control, the object stage caused by the movement between the divided areas of the object stage unique to the exposure apparatus to which the exposure method of the present invention is applied is applied. Position errors in the non-scanning direction can be reliably reduced.

In the actual exposure operation, while performing the movement operation between the actual partitioned areas while correcting the position of the object stage in the non-scanning direction in consideration of the first correction value group, The object stage is moved in the scanning direction before and after the movement operation between the divided areas to perform exposure to form a pattern in each divided area on the photosensitive object (second step). Therefore, when the movement operation of the object stage between the divided areas ends and the exposure to the next divided area is started, the displacement of the object stage in the non-scanning direction due to the movement operation between the divided areas is almost complete. Correction is surely performed, and exposure is performed in this state. Therefore, a pattern is accurately formed in each of the partitioned areas on the photosensitive object by exposure performed in a state where there is almost no positional error in the non-scanning direction due to the movement operation between the partitioned areas of the object stage. It becomes possible.

 In this case, in the first step, when the object stage is moved along a predetermined path, a position deviation which is a difference between a target position of the object stage in the scanning direction and a current position thereof. The position of the object stage in the scanning direction can be corrected in consideration of a second group of correction values that makes the value of the object stage approach zero.

 In this case, prior to the first step, an experiment or the like for obtaining the second correction value group may be performed. However, prior to the first step, A third step of repeatedly obtaining the second correction value group by learning control while moving the object stage in the scanning direction in the same manner as when moving in the scanning direction is further included.

 According to a third aspect of the present invention, in a third aspect, an object stage holding a photosensitive object is moved in a predetermined scanning direction, and a plurality of divided areas on the photosensitive object are respectively exposed and a predetermined An exposure method for forming a pattern, comprising: a correction value corresponding to an operating condition selected from a plurality of correction value groups for ascending a position deviation, which is a difference between a target position and a current position of the object stage, to zero. A third exposure method including an exposure step of controlling the object stage according to the operating condition while correcting the position of the object stage based on a group.

[0024] According to this, in the exposure step, an operation condition selected from a plurality of correction value groups for ascending a position deviation, which is a difference between a target position and a current position of the object stage, to zero is considered. The object stage is controlled in accordance with the operating conditions while correcting the position of the object stage based on the corresponding correction value group. That is, a plurality of operating conditions are usually set as operating conditions of the object stage in the exposure process, but the difference between the target position and the current position of the object stage for each of the plurality of operating conditions. A plurality of correction value groups for ascending the position deviation to zero are obtained in advance by experiment or iterative learning control, and in the actual exposure process, a plurality of correction value groups corresponding to the operating conditions at that time are obtained. The object stage is controlled according to the operating conditions while correcting the position of the object stage based on the correction value group. Therefore, it is possible to control the object stage according to the operating conditions while correcting the position of the object stage regardless of the operating conditions. [0025] In this case, the plurality of correction value groups are obtained by continuously operating the operation pattern of the object stage when continuously exposing a plurality of partitioned areas on the same row and a plurality of partitioned areas on different rows. The operation pattern of the object stage at the time of exposure may include a correction value group individually corresponding to the operation pattern, or the plurality of correction value groups may include a plurality of operation sequences of the object stage. May be included.

 [0026] In the third exposure method of the present invention, the plurality of correction value groups may include a scanning operation and a step operation of the object stage in the scanning direction, and a step operation of a non-scanning direction orthogonal to the scanning direction. And a correction value group individually corresponding to the above.

 Each of the correction value groups may be determined in advance by performing an experiment or the like for each operating condition. Each of them can be obtained by learning control.

 [0028] In the third exposure method of the present invention, the predetermined pattern is formed on a mask, and at the time of exposure, the mask stage holding the mask and the object stage perform predetermined scanning. The predetermined pattern is transferred to each of a plurality of divided areas on the photosensitive object by synchronously moving in the directions. Further, in the exposing step, a positional deviation which is a difference between a target position and a current position of the mask stage is calculated. The position of the mask stage may be corrected based on a group of correction values approaching zero.

 In this case, the group of correction values for correcting the position of the mask stage is a force that can be obtained in advance by an experiment or the like. The group of correction values for correcting the position of the mask stage. Is a TV that is acquired by the repetitive learning control performed in advance.

[0030] In this case, in the exposing step, the two stages are stopped in the scanning direction between the exposure of one partitioned area and the exposure of the next partitioned area as the operating condition. Is set, and the acceleration of the two stages can be started after a lapse of a predetermined time from the end of the exposure of the one partitioned area. According to a fourth aspect of the present invention, in accordance with a fourth aspect of the present invention, a mask and a photosensitive object are synchronously moved in a predetermined scanning direction, and a pattern formed on the mask is placed on the photosensitive object. An exposure apparatus for transferring, said mask stage being capable of mounting said mask and being movable at least in said scanning direction; and being capable of mounting said photosensitive object and being movable at least in said scanning direction. A possible object stage; a first control system for controlling the object stage in accordance with a positional deviation that is a difference between its target position and a current position; and a first correction value group for ascending the positional deviation to zero. An object stage control system including a first learning controller obtained by iterative learning; a second control system controlling the mask stage according to a positional deviation that is a difference between its target position and a current position; The position A second learning controller for repeatedly acquiring a second group of correction values for ascending the difference to zero, wherein a command value corresponding to a current position of the object stage is set as the target position during the synchronous movement. A given mask stage control system; according to setting conditions, the first and second learning controllers are set to a connected state or a non-connected state with respect to a corresponding control system, and connected to a corresponding control system. The correction value group obtained by the specific learning controller set in the state is sequentially stored, and the control system in which the corresponding learning controller is disconnected is obtained in advance by the corresponding learning controller. And a control device for sequentially inputting a corresponding correction value group as the correction value of the position deviation.

According to this, for example, prior to exposure, the first learning controller is disconnected from the object stage control system, and the second learning controller is connected to the mask stage control system. When the setting conditions are set, the controller performs the setting according to the setting conditions, and the object stage control system and the mask stage control system move the mask stage and the object stage synchronously, that is, the object stage of the mask stage. The tracking control is performed for. At this time, the corresponding correction value group (first correction value group) obtained in advance by the first learning controller is sequentially input to the object stage control system as the correction value of the position deviation by the control device. Using the first correction value group, the object stage control system performs position correction of the object stage such that the position deviation of the object stage gradually approaches zero. Here, there is a second correction value group obtained in advance by the first learning controller. Otherwise, no correction is made in effect. In addition, in the following control of the mask stage with respect to the object stage, in parallel with the position correction of the object stage, the second correction controller acquires the second correction acquired by the second learning controller by repetitive learning control. The value group is stored.

 [0033] Alternatively, prior to exposure, setting conditions were set such that the first learning controller was connected to the object stage control system and the second learning controller was connected to the mask stage control system. In this case, the control device performs setting according to the setting conditions, and the object stage control system and the mask stage control system perform synchronous movement of the mask stage and the object stage, that is, follow-up control of the mask stage with respect to the object stage. Be done. At this time, a first correction value group obtained by the first learning controller by the repetitive learning control and a second correction value group obtained by the second learning controller by the repetitive learning control are obtained. The group is stored.

 [0034] In the exposure, a setting condition is set such that the first learning controller is disconnected from the object stage control system and the second learning controller is disconnected from the mask stage control system. In this case, the control device makes settings in accordance with the set conditions, and the object stage control system and the mask stage control system perform synchronous movement of the mask stage and the object stage. The pattern is transferred onto the photosensitive object. At this time, a corresponding correction value group previously acquired by the first learning controller (the first correction value group acquired in advance or the stored first correction value group) is sent to the object stage control system by the control device. In parallel with the sequential input of the correction value group as the correction value of the position deviation, the mask stage control system stores the corresponding correction value group previously acquired by the second learning controller as the corresponding correction value group. The second group of correction values is sequentially input as correction values of the position deviation. This allows the object stage control system to perform the position correction of the object stage such that the position deviation of the object stage gradually approaches zero by using the first correction value group. The position correction of the mask stage is performed so that the position deviation of the mask stage gradually approaches zero using the correction value group of 2.

As described above, in the present invention, scanning exposure is performed with the synchronization error between both stages being effectively reduced, and the first and second correction value groups are also determined in advance. Have iterative learning Since it is obtained by control, it is possible to reliably reduce the synchronization error between the mask stage and the object stage, which is unique to the exposure apparatus, so that the pattern formed on the mask can be accurately transferred onto the photosensitive object. It becomes possible.

 [0036] In this case, the setting conditions include a first condition for connecting the first learning controller to the object stage control system and a second condition for connecting the second learning controller to the mask stage control system. The two conditions can be settable. Alternatively, the setting conditions include a first condition for connecting the first and second learning controllers to the object stage control system and the mask stage control system, respectively, and the first and second learning controllers. The second condition for disconnecting the object stage control system and the mask stage control system can be set.

 According to a fifth aspect of the present invention, there is provided an exposure method for moving a photosensitive object in a predetermined scanning direction and exposing a plurality of divided areas on the photosensitive object to form a predetermined pattern in each divided area. An object stage on which the photosensitive object can be placed and which can be moved in a two-dimensional direction including the scanning direction and a non-scanning direction orthogonal to the scanning direction; and an object stage that controls the object stage and The position of the object stage is determined based on a correction value group corresponding to an operation condition selected from a plurality of correction value groups for ascending a position deviation, which is a difference between the target position and the current position, to zero. And a stage control system for performing correction.

[0038] According to this, an operation selected from a plurality of correction value groups for ascending the position deviation, which is the difference between the target position and the current position of the object stage, to zero, the stage control system force for controlling the object stage. The position of the object stage is corrected based on the correction value group corresponding to the condition. That is, a plurality of operating conditions are usually set as the operating conditions of the object stage. For each of the plurality of operating conditions, the position deviation, which is the difference between the target position of the object stage and the current position, is set to zero. A plurality of correction value groups to be asymptotically determined in advance by experiments or repetitive learning control, etc., and in the actual exposure process, the stage control system (or via the higher-order device force stage control system) A correction value group corresponding to the operating condition is selected from a plurality of correction value groups, and the object stage is controlled according to the operating condition while correcting the position of the object stage based on the correction value group. Therefore, depending on the operating conditions Instead, it is possible to control the object stage according to the operating conditions while correcting the position of the object stage.

 [0039] In this case, the plurality of correction value groups are obtained by continuously operating the operation pattern of the object stage when continuously exposing a plurality of partitioned areas on the same row and a plurality of partitioned areas on different rows. A correction value group individually corresponding to the operation pattern of the object stage at the time of exposure may be included, or the correction value group may individually correspond to a plurality of operation sequences of the object stage. May be included.

 [0040] In the second exposure apparatus of the present invention, each of the correction value groups is individually set for each of a scanning operation and a step operation in the scanning direction of the object stage and a step operation in the non-scanning direction. A corresponding group of correction values may be included.

 [0041] Each of the correction value groups may be obtained by repetitive learning control performed in advance for each operating condition.

 [0042] In this case, when the mask on which the predetermined pattern is formed can be placed and at least the mask stage movable in the scanning direction is further provided, the stage control system includes one section. When executing the movement sequence of the two stages in which the object stage and the mask stage stop in the scanning direction between the exposure of the region and the exposure of the next partitioned region, the exposure of the one partitioned region is performed. After a lapse of a fixed time from the end, the acceleration of the two stages may be started.

 [0043] In the second exposure apparatus of the present invention, the stage control system is based on a correction value group for ascending a position deviation, which is a difference between a target position and a current position of the mask stage, to zero. The position of the mask stage at the time of synchronous movement with the object stage can be further corrected.

 [0044] In this case, the group of correction values for correcting the position of the mask stage may have been obtained by repetitive learning control performed in advance.

[0045] In this case, the stage control system includes a movement sequence of the two stages in which the two stages stop and stop in the scanning direction between the exposure of one partitioned area and the exposure of the next partitioned area. When executing the above, the acceleration of the two stages may be started after a lapse of a fixed time from the end of the exposure of the one partitioned area. According to a sixth aspect of the present invention, in a sixth aspect, the mask and the photosensitive object are synchronously moved in a predetermined scanning direction, and the pattern formed on the mask is moved to a plurality of partitioned areas on the photosensitive object. An exposure apparatus for transferring and transferring, wherein a mask stage capable of mounting the mask and movable at least in the scanning direction; and capable of mounting the photosensitive object, the scanning direction and orthogonal to the scanning direction. An object stage movable in a two-dimensional direction in a non-scanning direction; and controlling the two stages; and controlling the two stages with respect to the scanning direction between exposure of one segmented region and exposure of the next segmented region. A stage control system that starts acceleration of the two stages after a lapse of a predetermined time from the end of exposure of the one partitioned area when executing the movement sequence of the two stages in which the two stages are stopped. This is the third exposure system.

 According to this, a stage control system for controlling the mask stage and the object stage is capable of performing both stages in the scanning direction between the exposure of one partitioned area and the exposure of the next partitioned area. When executing the movement sequence of both stages to be stopped, acceleration of both stages is started after a certain period of time has elapsed from the end of exposure of one partitioned area. For this reason, the stop time of both stages becomes constant (the deceleration time is usually constant), so that the reproducibility of the attenuation of the vibration generated when both stages are decelerated after the exposure of the divided area can be increased. As a result, at the start of acceleration, the same vibration (vibration within an allowable level) can always be left, and when learning control is repeatedly applied to at least one of the object stage and the mask stage, for example. In, the effect of the repetitive learning control can be improved. Iterative learning control is an effective force for phenomena such as vibration with reproducibility.

 Further, in the lithographic process, it is possible to improve the productivity of a highly integrated microdevice by transferring a pattern onto a photosensitive object using the first to third exposure methods of the present invention. It is possible. Therefore, it can be said that the present invention is a device manufacturing method using a shift of the first to third exposure methods of the present invention, in view of still another viewpoint.

 Brief Description of Drawings

FIG. 1 is a view schematically showing a configuration of an exposure apparatus according to an embodiment of the present invention.

FIG. 2 (A) is a plan view showing a reticle stage. FIG. 2 (B) is a plan view showing a wafer stage.

 FIG. 3 is a block diagram showing a stage control system of the exposure apparatus of the embodiment.

 FIG. 4 (A) is a plan view showing a relationship between a slit-shaped illumination area and a shot area S on a wafer inscribed in an effective field of the projection optical system.

 FIG. 4 (B) is a diagram showing the relationship between stage movement time and stage speed.

 5 is a flowchart showing a processing algorithm of main controller 50 in FIG. 1.

 FIG. 6 is a view schematically showing a movement locus of an illumination slit center when exposing a plurality of shot areas on a wafer W by the exposure apparatus of the embodiment.

 [FIG. 7] Center P of illumination slit ST on wafer when shot areas S 1, S 2, and S 3 are sequentially exposed

 one two Three

 FIG. 3 is a diagram showing a trajectory passing over each shot.

 FIG. 8 is a diagram showing a speed curve of a wafer stage in a movement operation in a first mode.

 FIG. 9 is a diagram showing a speed curve of a wafer stage in a movement operation in a second mode.

 FIG. 10 is a diagram showing a speed curve of a wafer stage in a movement operation in a third mode.

 FIG. 11 is a flowchart illustrating an embodiment of a device manufacturing method.

 FIG. 12 is a flowchart showing a specific example of step 204 in FIG. 11.

 BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

FIG. 1 schematically shows an entire configuration of an exposure apparatus 10 according to an embodiment of the present invention. The exposure apparatus 10 is a projection exposure apparatus that performs an exposure operation by a step-and-scan method, which is currently becoming the mainstream as a lithography apparatus for manufacturing semiconductor elements. The exposure apparatus 10 projects an image of a part of a circuit pattern formed on a reticle R serving as a mask onto a wafer W serving as a photosensitive object via a projection optical system PL, and combines the reticle R and the wafer W. By scanning relative to the field of view of the projection optical system PL in a one-dimensional direction (here, the Y-axis direction which is the horizontal direction in FIG. 1), the entire circuit pattern of the reticle R is placed on the wafer W. Each of a plurality of shot areas (hereinafter, abbreviated as “shot areas” as appropriate) is transferred by a step-and-scan method.

The exposure apparatus 10 includes an illumination unit ILU, a reticle stage RST as a mask stage, a projection optical system PL, a wafer stage WST as an object stage, and a control thereof. System.

 The illumination unit ILU includes, for example, a BMU (beam matching unit) and a light source for exposure (not shown) including a pulse laser light source such as a KrF excimer laser having an output wavelength of 248 nm or an ArF excimer laser having an output wavelength of 193 nm. It is connected via a light-sending optical system that includes an optical system for adjusting the optical axis, which is called as a part.

 Here, pulsed laser light in the ultraviolet region (hereinafter also referred to as “excimer laser light”, “pulse illumination light” or “pulse ultraviolet light”) from the light source is used as illumination light for exposure (hereinafter referred to as appropriate). Illumination light ") IL is used for mass production of microcircuit devices with the integration degree and fineness equivalent to semiconductor memory elements (D-RAM) of 256M (mega) to 4G (giga) bit class or higher. This is to obtain a pattern resolution of about 0.25 to 0.10 m, the minimum line width required for manufacturing. Therefore, pulsed laser light in the vacuum ultraviolet range such as F laser is output as the light source.

 2

 A laser light source may be used.

An example of a step-and-scan type exposure apparatus using an excimer laser as a light source is disclosed in, for example, JP-A-2-229423 and corresponding US Pat. Nos. 4,924,257 and 6-132195. It is disclosed in the official gazette and the corresponding US Pat. No. 5,477,304, and in Japanese Patent Laid-Open No. 7-142354 and the corresponding US Pat. No. 5,534,970. Therefore, also in the exposure apparatus 10 of FIG. 1, the basic technology disclosed in each of the above-mentioned patent publications can be applied as it is or partially modified. To the extent permitted by national law in the designated country (or selected elected country) specified in this international application, the disclosures in each of the above-mentioned publications and corresponding US patents are incorporated herein by reference.

The illumination unit ILU includes an illumination system housing, an illuminance uniforming optical system including an optical integrator housed in a predetermined positional relationship inside the housing, a relay lens, a variable ND filter, and a variable field stop (reticle blind). Or, it is also called a masking blade), and an illumination optical system including a dichroic mirror and the like (the deviation is not shown). The configuration of an illumination optical system similar to that of the present embodiment is disclosed in, for example, Japanese Patent Application Laid-Open No. 2001-313250 and US Patent Application Publication No. 2003Z0025890 corresponding thereto. In addition, for example, JP-A-6-349701 and corresponding US Pat. The illumination optical system may be configured similarly to the illumination optical system disclosed in, for example, 534,970. Here, a fly-eye lens, an internal reflection type integrator (such as a rod integrator), or a diffractive optical element is used as the optical integrator. To the extent permitted by the national laws of the designated or designated elected country in this international application, the disclosures in the above publications and corresponding U.S. patent application publications or U.S. patents shall be incorporated as part of this specification. .

 In this illumination unit ILU, on a reticle R on which a circuit pattern or the like is drawn, a slit-shaped illumination area (a rectangular illumination area elongated in the X-axis direction) RA (FIG. 2 (A ) Is illuminated with illumination light IL with substantially uniform illuminance.

 [0058] The reticle stage RST is arranged below the illumination unit ILU, as shown in FIG. The reticle stage RST is actually driven by a reticle drive system 29 including an actuator such as a linear motor, and is linearly driven on a reticle base surface plate (not shown) with a large stroke in the Y-axis direction. The micro drive is performed in the axial direction, the Y axis direction, and the Θ z direction (the rotation direction around the Z axis). The reticle R is sucked and held on the reticle stage RST.

 [0059] A movable mirror 31 that reflects a laser beam from a reticle laser interferometer (hereinafter abbreviated as "reticle interferometer") 30 is fixed to reticle stage RST. Is always detected by the reticle interferometer 30 with a resolution of, for example, about 0.5 to lnm.

 Here, actually, as shown in the plan view of FIG. 2A, an X-axis movable mirror 31x extending in the Y-axis direction is fixed to the + X side end of reticle stage RST. Also, at the end in the + Y direction, two Y-axis movable mirrors 31y, 31y each composed of a retro-reflector are fixed, respectively.

 1 2

 Yes. The former movable mirror 31x is irradiated with a laser beam LR parallel to the X axis, and the latter is moved.

 X

 Laser beams LR and LR are irradiated on the mirrors 31y and 31y, respectively, parallel to the Y axis.

 1 2 L R The laser beams LR, LR, LR are supplied from the reticle interferometer 30 in FIG.

 X L R

 ing.

 In this case, the laser beam reflected by the Y-axis moving mirror 3

 1 2

The mirrors LR and LR are reflected back by the reflection mirrors 39A and 39B, respectively. That is, The Y-axis interferometer for the reticle is a double-pass interferometer, so that even if the reticle stage RST rotates, the laser beam will not be displaced. Note that, in FIG. 2A, reference numeral RA denotes a slit-shaped illumination area on the reticle R.

The reticle stage RST as described above has an X-axis movable mirror 31χ and two Υ-axis movable mirrors 31y, 31y fixed thereto, and correspondingly, the reticle interferometer 30 also has a three-axis laser interference. Total

1 2

 In FIG. 1, these are representatively shown as a moving mirror 31 and a reticle interferometer 30.

 [0063] For example, the end surface of reticle stage RST may be mirror-finished to form a reflection surface (for example, equivalent to the reflection surface of moving mirror 3 lx)! ,.

 The output of the reticle interferometer 30 is supplied to the reticle stage control unit 33, the synchronous control unit 80 as a control device, and the main control device 50 via the same. The reticle stage control unit 33 basically controls the reticle drive system 29 that drives the reticle stage RST such that the position information output from the reticle interferometer 30 matches the command value (target position).

 [0065] As the projection optical system PL, here, both the object plane (reticle R) side and the image plane (wafer W) side are telecentric and have a circular projection visual field, and quartz or fluorite is used as an optical glass material. A 1Z4 (or 1Z5) refraction optical system consisting of only a refractive optical element (lens element) is used. The direction of the optical axis AX of the projection optical system PL is the Z-axis direction. In this case, the imaging luminous flux from the portion of the circuit pattern area on the reticle R illuminated by the pulsed ultraviolet light Projecting optical system PL, the resist on the wafer W attracted onto the wafer stage WST described later The image is projected on the layer reduced to 1Z4 or 1Z5.

 As described in Japanese Patent Application Laid-Open No. 3-282527 and US Pat. No. 5,220,454 corresponding thereto, the projection optical system PL includes a refractive optical element and a reflective optical element (concave mirror and beam). Of course, a catadioptric system combined with a splitter, etc. may be used.

The wafer stage WST is levitated and supported on a base (not shown) through a predetermined clearance by a gas static pressure bearing (not shown) provided on the bottom surface, and includes a wafer drive system including an actuator such as a linear motor. 48 drives freely in the X-axis and Y-axis directions. At the same time, they are minutely driven in the Z-axis direction, 0z direction, 0x direction (rotation direction around the X-axis), and 0y direction (rotation direction around the Y-axis).

The wafer driving system 48 is controlled by a wafer stage control unit 78.

 [0069] A wafer holder (not shown) having a substantially circular shape is provided on wafer stage WST, and wafer W is electrostatically attracted to this wafer holder, and is flattened and held. The temperature of the wafer holder is controlled in order to suppress expansion and deformation due to heat accumulation during exposure of the wafer w.

 [0070] Note that a focus (not shown in Fig. 1) for detecting a deviation (focus error) and an inclination (leveling error) in the Z-axis direction between the imaging plane of the force projection optical system PL and the surface of the wafer W. 'A leveling detection system is provided near the projection optical system PL, and the wafer stage control unit 78 responds to the focus error signal from the focus' leveling detection system 検 出 the leveling error signal to the wafer drive system 48. Outputs a drive command. An example of such a focus' leveling detection system is disclosed in detail in Japanese Patent Application Laid-Open No. 7-201699. The output of the focus leveling detection system is also supplied to the synchronous control unit 80 via the wafer stage control unit 78 and the main controller 50 via the synchronous control unit 80.

The position of the wafer stage WST is sequentially measured by the laser interferometer system 76. To describe this in more detail, each of the Y-side and X-side end faces of the wafer stage WST is mirror-finished to form a reflection surface. Then, as shown in FIG. 2 (B), the X-side reflection surface of the wafer stage WST is irradiated with two laser beams LWX and LWX at an interval D along an optical path parallel to the X-axis, respectively. I have. These two

 1 2

 The laser beams LWX and LWX are the same from the X axis passing through the optical axis AX of the projection optical system PL.

 1 2

 At one distance. The Y-side reflecting surface of wafer stage WST is irradiated with two laser beams LWY and LWY at an interval D along an optical path parallel to the Y-axis, respectively.

 1 2

 The These two laser beams LWY and LWY pass through the optical axis AX of the projection optical system PL.

 1 2

 At the same distance from the Y axis.

[0072] The laser beams LWX, LWX, LWY, and LWY are respectively the laser interferometer system of FIG. It is supplied from the interferometer that makes up the system 76.

The output of the four-axis laser interferometer system 76 is supplied to the wafer stage control unit 78, the synchronous control unit 80, and the main controller 50 via the same. Synchronous control unit 80 has two X-axis interferometers that use laser beams LWX and LWX as measuring axes.

 1 2

 The X position of the wafer stage WST is measured based on the average value of the outputs (WX, WX), and the

 1 2

 The outputs (WY, WY) of the two Y-axis interferometers with the beam LWY, LWY as the measuring axis

 1 2 1 2 Measures Y position of wafer stage WST based on average value and measures laser beam LWX

 The difference between the output of the interferometer with one axis and the output of the interferometer with the laser beam LWX as the measuring axis (or

 2

 Is the output of the interferometer with the laser beam LWY as the measuring axis and the laser beam LWY as the measuring axis.

 The rotation angle of the wafer stage WST in the XY plane is calculated based on the difference between the output of the interferometer and the interval D).

 As described above, a plurality of laser interferometers on the wafer side are provided. In FIG. 1, these are typically shown as a laser interferometer system 76. It should be noted that a moving mirror having a plane mirror force may be provided instead of each of the above-described reflecting surfaces formed on wafer stage WST.

 On the wafer stage WST, there is provided a reference mark plate FM whose surface is made substantially the same height as the surface of the wafer W. Various fiducial marks are formed on the surface of this fiducial mark plate FM. These fiducial marks are used to check the detection center point of each alignment detection system (calibration), and to check the detection center point and the projection optical system during projection. It is used for measuring the distance from the center (base line), checking the position of the reticle R with respect to the wafer coordinate system, or checking the position in the Z direction of the best imaging plane conjugate to the reticle R pattern surface.

Further, in exposure apparatus 10 of the present embodiment, a synchronous control unit 80 for synchronously moving reticle stage RST and wafer stage WST is provided in the control system. The synchronous control unit 80 controls the reticle drive system 29 by the reticle stage control unit 33 and the wafer drive system by the wafer stage control unit 78 when moving the reticle stage RST and the wafer stage WST synchronously, especially during scanning exposure. In order to link the control of 48 with each other, the position information of the reticle R and the position of the wafer W measured by the reticle interferometer 30 and the laser interferometer system 76 are monitored in real time, and their mutual relationship is monitored. Is managed to be a predetermined one. The synchronous control unit 80 is controlled by various commands and parameter setting information from the main controller 50. As described above, in the present embodiment, the stage control system for controlling both stages RST and WST by the synchronous control unit 80, the reticle stage control unit 33, and the wafer stage control unit 78 (this will be further described later). ) Is composed.

[0077] In the exposure apparatus 10 of the present embodiment, the control system is actually a unit of the above-described light source and each unit of the exposure apparatus main body (illumination unit ILU, reticle stage RST, wafer stage WST, wafer transport system, and the like). It is constructed as a distributed system comprising a plurality of unit-side computers (microprocessors and the like) for individually controlling each of the units, and a powerful main controller 50 such as a workstation for controlling these unit-side computers collectively. Is

In the present embodiment, the plurality of unit-side computers cooperate with the main controller 50 to execute a series of exposure processing on a plurality of wafers. The entire sequence of the series of exposure processing is controlled by the main controller 50 in accordance with a setting file of a predetermined exposure condition called a process program stored in a memory (not shown).

The process program is based on the exposure processing file name created by the operator, and includes information on the wafer to be exposed (the number of processed wafers, shot area size, shot area array data, alignment mark arrangement data, alignment conditions, etc.). ), Information about the reticle to be used (pattern type data, arrangement data of each mark, size of the circuit pattern area, etc.), and information about exposure conditions (exposure amount, focus offset amount, scan speed offset amount, projection magnification) Offset amount, correction amount of various aberrations and image distortion, numerical aperture of illumination optical system 設定 set value of coherence factor _σ value, etc., numerical aperture set value of projection optical system, etc.) are stored as a package of parameters. It is.

Main controller 50 decodes the process program instructed to be executed, and sequentially instructs the corresponding unit-side computer as a command on the operation of each component required for the wafer exposure processing. At this time, when each unit computer completes one command normally, it sends a status to that effect to the main controller 50, and the main controller 50 receives the status. Sends the following command to the unit-side computer.

 FIG. 3 shows a block diagram of the stage control system 90 of the scanning exposure apparatus 10 according to the present embodiment. The stage control system 90 includes a synchronous control unit 80, a wafer stage control system 92, and a reticle stage control system 94.

 [0082] The wafer stage control system 92 performs the following based on the position command value P for the wafer stage WST output from the synchronous control unit 80 in response to an instruction from the main controller 50.

 W

 This is a feedback control system that performs feedback control of the position of the wafer stage WST. The wafer stage control system 92 calculates the difference between the position command value P and the position of the wafer stage WST.

 W

 A subtractor 52 for calculating a certain position deviation, an adder 54 provided at an output stage of the subtractor 52, and a PID controller for performing, for example, a (proportional + integral + differential) control operation using the output signal of the adder 54 as an operation signal. (A PI controller that performs a (proportional + integral) control operation) includes a wafer stage controller 56 that also generates power, and a wafer stage system as a control target Wp. In the present embodiment, a first control system that controls the wafer stage WST according to the positional deviation is configured by the wafer stage controller 56.

Here, the controlled object Wp is directly driven by the force wafer driving system 48, the wafer stage WST, and the position information of the wafer stage WST is transmitted by the laser interferometer system 76. The position is measured, and the measured position information is fed back to the subtractor 52 to form a position control loop. In terms of its meaning, it can be said that the control target Wp is substantially a wafer stage system including the wafer drive system 48 and the wafer stage WST. Therefore, hereinafter, it is described as a wafer stage system Wp (this transfer function is Wp).

An output terminal of the subtractor 52 constituting the wafer stage control system 92 is connected to an input terminal of an ILC controller 58 as a first learning controller via a circuit opening / closing switch SW1, and an output of the ILC controller 58 is provided. The terminal is connected to the first input terminal of the adder 54. The output terminal of the subtractor 52 is connected to the second input terminal of the adder 54. Therefore, when the switch SW1 is ON, the adder 54 outputs an operation signal obtained by adding the position deviation ΔPw output from the subtractor 52 and the correction value output from the ILC controller 58 to the wafer stage controller. Output to 56. The correction value output from the ILC controller 58 is also output to the synchronous control unit 80.

[0086] Here, the ILC controller 58 will be briefly described.

 [0087] This ILC controller 58 can be configured to include an ILC integrator and an ILC compensator connected to the output stage of the ILC integrator. The ILC integrator is a memory that stores a tracking error, and the transfer function of the ILC integrator is represented by z-i / d-z-, where Z is the z-transformation operator. In this ILC integrator, the tracking (following) error that occurs in each iteration is added to the value in the memory each time.

 [0088] The ILC compensator can be configured to include, for example, a learning gain, a filter, and the like.

 The learning gain K is a parameter used for adjusting the convergence speed and the convergence stability of the learning.The magnitude of the learning gain K is defined as the transfer function of the ILC compensator Gc and the transfer function of the control target of the ILC controller 58 (ILC controller Assuming that the closed-loop transfer function of the feedback control system excluding 58 is Gp, it is set to satisfy | 1 GcGp I <1, which is the learning convergence condition. Here, assuming that the transfer function of the wafer stage controller is Wc, there is a relationship of Gp = Wc−Wp / (l + Wc′Wp).

 [0089] The filter is used for fine adjustment of phase characteristics and gain characteristics, noise removal, and the like.

 This filter has, for example, an inverse system having an inverse transfer function to the product of the transfer function of the wafer stage controller and the transfer function of the wafer stage system, and a filter for removing high-frequency components output from the inverse system. A combination with a low-pass filter can be applied.

 In addition, a negative dead time element may be used to improve the convergence stability of learning.

 The reticle stage control system 94 determines the position of reticle stage RST based on position command value P for reticle stage RST output from synchronous control unit 80.

 R

 This is a feedback control system that performs feedback control. The reticle stage control system 94 calculates a position deviation Δ で which is a difference between the position command value P and the position of the reticle stage RST.

 R R

A subtractor 62, an adder 64 provided at the output stage of the subtractor 62, and a PID controller (A) which performs, for example, a (proportional + integral + differential) control operation using the output signal of the adder 64 as an operation signal. Or a (PI controller that performs (proportional + integral) control operation) a reticle stage controller 66 that also configures the force, and a reticle stage system as the controlled object Rp. In the present embodiment, a reticle stage controller 66 configures a second control system that controls the reticle stage RST according to its position deviation.

Here, reticle stage RST is driven by force reticle drive system 29, which is a reticle drive system 29, and position information of reticle stage RST is measured by control reticle interferometer 30. The measured position information is fed back to the subtracter 62 to form a position control loop. In that sense, it can be said that the control target Rp is substantially a reticle stage system including the reticle drive system 29 and the reticle stage RST. Therefore, in the following, it is described as reticle stage system Rp

[0093] The output terminal of the subtractor 62 constituting the reticle stage control system 94 is connected to the input terminal of an ILC controller 68 as a second learning controller via a circuit opening / closing switch SW2. The output terminal is connected to the first input terminal of the adder 64. The output terminal of the subtractor 62 is connected to the second input terminal of the adder 64. Therefore, when the switch SW2 is ON, the adder 64 outputs to the reticle stage controller 66 an operation signal obtained by adding the position deviation output from the subtractor 62 and the correction value output from the ILC controller 68. .

 [0094] The ILC controller 68 is configured similarly to the above-described ILC controller 58. The correction value output from the ILC controller 68 is also output to the synchronous control unit 80.

 [0095] The synchronous control unit 80 is one of the unit-side computers, and has various roles such as the following a.

[0096] a. The synchronous control unit 80 outputs the position command value P to the subtractor 52 based on the instruction from the main controller 50.

 W

[0097] b. The synchronous control unit 80 controls the position information (WX, WX, WY, WX, WX) of the wafer stage WST, which is the output of the wafer stage control system 92, for example, when performing control to follow the reticle stage RST to the wafer stage WST. WY) based on the following formula (1) The target values (R ', R', R ') of the three axes measured values (R, R, R) of the reticle interferometer 30 that measures the position of the reticle R, that is, the reticle stage control. system

X L R X L R

 Output to 94 as position command value P.

 [0098] [Number 1]

[0099] In Equation (1), the matrix of 3 rows and 4 columns of the first term on the right side is a transform coefficient matrix, and the matrix of 3 rows and 1 column of the second term on the right side is an offset.

[0100] The position information (WX, WX, WY, WY) described above is transmitted to the laser interferometer system 76.

 1 2 1 2

 It is a measurement value of each interferometer constituting.

 [0101] The c-synchronized control unit 80, based on instructions from the main controller 50, moves the reticle stage RST independently or independently of the wafer stage WS, and the like. The position command value P corresponding to the instruction from the control device 50 is output.

 R

 [0102] d. The synchronous control unit 80 turns on and off (ON / OFF) the switches SW1 and SW2 according to the set conditions.

 [0103] e. When the switch SW1 is “ON”, the synchronous control unit 80 sequentially fetches the correction values output from the ILC controller 58 for each repetition, and divides the sequentially fetched correction value group into time-series data. In a predetermined storage area (buffer memory) of an internal memory (not shown). When the switch SW2 is “ON”, the synchronous control unit 80 sequentially fetches correction values output from the ILC controller 68 at each repetition, and stores the sequentially fetched correction value groups as time-series data. Data is stored in the corresponding storage area (buffer memory) of the memory. In the present embodiment, a buffer memory is prepared in advance in the internal memory of the synchronous control unit 80 for each operating condition, and a force for acquiring a correction value group into each buffer memory is set to a plurality of operating conditions of the wafer stage WST. Is done individually.

[0104] f. When the switch SW1 is "OFF", the synchronous control unit 80 Under the same operating conditions of the wafer stage WST as before, select a buffer memory that stores a group of correction values acquired in advance, and use the group of correction values in the correction buffer as the correction value of the position deviation to control the wafer stage. Input to 92 sequentially through the third input terminal of adder 54 (see end point e). Further, when performing control to follow the reticle stage RST with respect to the wafer stage WST when the switch SW2 is OFF, the synchronous control unit 80 uses the correction value group acquired in advance by the learning controller 68 as the position deviation correction value. Are sequentially input to the reticle stage control system 94 via the third input terminal (see end point f) of the adder 64.

 In FIG. 3, reticle stage control unit 33 and wafer stage control unit 78 are indicated by two-dot chain lines.

Next, the basic scanning procedure of the wafer stage at the time of exposing one shot area performed by the stage control system 90 will be described with reference to FIGS. 4 (A) and 4 (B). I will explain briefly.

 FIG. 4 (A) shows a slit-shaped illumination area on the wafer (an area conjugate with illumination area RA on reticle R, inscribed in effective field PL ′ of projection optical system PL; The relationship between the ST and the shot area S as one sectioned area is shown in a plan view, and FIG. 4 (B) shows the relationship between the stage movement time and the stage speed. Actually, exposure is performed by moving the shot area S with respect to the illumination slit ST in the direction opposite to the arrow Y, but in FIG. 4A, the stage movement time and the stage movement shown in FIG. Illumination slit ST is shown to move with respect to shot area S to correspond to the speed relation table.

[0108] First, as a basic (general) scanning procedure, the center P of the illumination slit ST is positioned at a position away from the end of the shot area S by a predetermined amount, and acceleration of the wafer stage WST is started. . At this time, at the same time, reticle stage RST is started to be opposed to wafer stage WST and at an acceleration that is the reciprocal multiple of the projection magnification of the acceleration of wafer stage WST. Then, when wafer stage WST and reticle stage RST approach a predetermined speed, synchronous control of reticle R and wafer W is started. The time T from the start of acceleration of both stages WST and RST to the start of synchronous control is the acceleration time Call it. After the start of the synchronous control, the tracking control of the reticle stage RST with respect to the wafer stage WST is performed until the displacement error between the wafer and the reticle has a predetermined relationship, and exposure is started. The time T from the start of the synchronous control to the start of the exposure is called a settling time.

 2

 [0109] The time (T + T) from the start of acceleration to the start of exposure is called a pre-scan time.

 1 2

 . At this time, if the average acceleration at the acceleration time T is a and the settling time is T,

 1 2

Moving distance at the time of Yang can be expressed as ^{(1Z2) -aT 2 + aT ·} Τ.

 1 1 2

 [0110] Further, the exposure time に よ り during which the exposure is performed by moving at a constant speed is represented by L for the shot area length, and illumination slit.

 Three

 If the width of the scanning ST in the scanning direction is w, T = (L + w) Z (a'T), and the moving distance is L +

 3 1

 W.

 At the end of the exposure time T, the transfer of the reticle pattern to the shot area S ends.

 Three

 However, in order to improve the throughput, in the step-and-scan method, the normal reticles R are alternately scanned (reciprocating scans) to sequentially expose the next shot area. It is necessary to further move reticle R from the end of exposure by the same distance as, and return reticle R to the scanning start position for the next shot area exposure. At this time, the wafer (wafer stage) is moved in the scanning direction corresponding to the reticle (reticle stage). The time for this is the constant speed overscan time (post-settling time) T and the deceleration overscan time T, and (T + T

 4 5 4 5

) Is the overscan time. The travel distance in this overscan time is given by b where deceleration in deceleration overscan time T is b.

5-(1/2) -bT ² — b'T ·

 5 5

T, and this distance is ^{(1Z2) -aT 2 + aT ·} Τ become as T, T, and the deceleration b is set

4 1 1 2 4 5

 Is determined.

 [0112] In a general control system, a = —, so it is easiest to set T = T and T = T

 1 5 2 4

 Be the law.

Next, with respect to the operation when the pattern of reticle R is sequentially transferred to a plurality of shot areas on wafer W by exposure apparatus 10 of the present embodiment, main controller 50 (more precisely, main controller 50) 5 will be described mainly with reference to the flowchart of FIG. 5 showing the processing algorithm of the CPU in FIG. Here, a case where exposure is performed on a plurality of (for example, 76) shot areas as shown in FIG. 6 along a path as shown in FIG. explain. Here, the path in FIG. 6 shows a trajectory in which the center P of the above-mentioned illumination slit ST passes over each shot area, and a solid line part in this trajectory indicates the illumination slit ST at the time of exposure of each shot area. The path of the center P (hereinafter also referred to as “point P”) is shown, the dotted line indicates the movement locus of point P between adjacent shot areas in the same row in the non-scanning direction, and the dashed line indicates the path between different rows. The trajectory of point P is shown. Actually, the force at which the point P is fixed and the wafer W moves. In FIG. 6, in order to facilitate the explanation, the point P (the center of the illumination slit ST) moves on the wafer W. It is illustrated as follows.

First, prior to the processing in the flowchart of FIG. 5, the main controller 50 transmits a reticle alignment system (not shown), a reference mark plate FM on the wafer stage WST, and a reference mark plate via the unit computers. Preparation work such as reticle alignment using the wafer alignment detection system illustrated, baseline measurement of the wafer alignment detection system, and wafer alignment (EGA method or the like) is performed.

 [0115] The reticle alignment, baseline measurement, and the like are disclosed in detail in, for example, JP-A-7-176468 and US Patent No. 5,646,413 corresponding thereto. Are disclosed in detail in JP-A-61-44429 and corresponding US Pat. No. 4,780,617). To the extent permitted by national laws of the designated country (or selected elected country) designated in this international application, the disclosures in each of the above-mentioned publications and the above-mentioned US patents corresponding thereto are incorporated herein by reference. .

[0116] Upon completion of such preparation work, the flowchart of Fig. 5 starts.

First, in step 102, a counter n indicating a row number to which a shot area to be exposed belongs and a counter m indicating a shot area number in the row are both initialized to 1 (m ^ 1, 1).

 [0118] In the next step 104, the first shot S on the wafer, that is, the first shot in the first row

 1

 Various setting information required for exposure of the yacht area S is transmitted to the synchronous control unit 80. here

 1

The various setting information includes control information relating to the position control of the reticle stage and the wafer stage described above, for example, EGA parameters (for example, in the X and Y directions of the wafer) obtained by an EGA type wafer alignment performed prior to exposure. Offset Ox, Oy, orthogonality error w of stage coordinate system that regulates wafer movement, wafer rotation error Θ, wafer Setting values of the scaling (rx, ry) errors rx, ry in the X and Y directions (this is the data for determining the position of the wafer during exposure), and correction parameters related to the positions of both stages during exposure (For example, bending information of the moving mirror on the reticle stage (or wafer stage) side) and data related to exposure control, such as data on the pulse energy density and pulse emission number of the excimer laser, and the set exposure sequence data ( This includes the blue direction for the scan direction (plus or minus scan). Also, in some cases, error information of each mechanism when the stage is moved is also included.

 [0119] In the next step 106, movement of reticle stage RST and wafer stage WST is instructed to synchronous control unit 80.

 [0120] Based on the instruction from main controller 50, synchronous control unit 80 sets wafer stage to move wafer W to a scanning start position (acceleration start position) for exposure of a first shot on wafer W. The control unit 78 is instructed. Thereby, wafer stage WST is moved to the above-described acceleration start position by wafer stage control unit 78 via wafer drive system 48. Next, the synchronous control unit 80 monitors the measured values of the interferometer system 76 and the reticle interferometer 30 and, via the wafer stage control unit 78 and the reticle stage control unit 33, respectively, the reticle drive system 29 and the reticle stage control unit 33 described above. Controls the drive system 48 to start relative scanning in the Y-axis direction between the reticle stage RST and the wafer stage WST.

 At this time, main controller 50 waits in step 108 for the acceleration of both stages RST and WST to the target running speed to be completed. When the acceleration of both stages RST and WST is completed, the process proceeds to step 110, and the light emission of the light source is started.

 [0122] Almost simultaneously with the start of light emission of the light source, the synchronization control unit 80 starts the pre-exposure synchronization settling operation of both stages RST and WST.

As described above, the light emission of the light source is started before the synchronous stabilization of both stages RST and WST is completed and the exposure is started, but the main controller 50 controls the reticle interferometer 30 to perform the measurement. Based on the value, the movement of the predetermined blade of the movable reticle blind is controlled in synchronization with the reticle stage RST, and the extra portion outside the pattern area of the reticle R is exposed. It is the same as a normal scanning 'stepper'.

[0124] When both stages RST and WST reach the constant velocity synchronization state, the pattern area of reticle R starts to be illuminated by illumination light IL from illumination unit ILU, and scanning exposure is started.

 [0125] In particular, during the above-described scanning exposure, the synchronous control unit 80 determines that the moving speed Vr of the reticle stage RST in the Y-axis direction and the moving speed Vw (= Vy) of the wafer stage WST in the Y-axis direction are equal to the projection optical system PL. Synchronous control is performed so that the speed ratio according to the projection magnification (1Z4 times or 1Z5 times) is maintained.

 [0126] Then, different areas of the pattern area of reticle R are sequentially illuminated with illumination light IL, and the illumination of the entire pattern area is completed, thereby completing the first-shot scanning exposure on wafer W. Thus, the pattern of the reticle R is reduced and transferred to the first shot via the projection optical system PL.

 [0127] During the above-described scanning exposure, main controller 50 waits for the end of the exposure in step 112.

 When the first-shot scanning exposure is completed as described above, the determination in step 112 is affirmed, and the flow advances to step 114 to stop laser beam irradiation. In stopping the irradiation, the light emission of the light source itself may be stopped, or a shutter (not shown) in the light source may be closed.

 [0129] In the next step 116, by referring to the counter m, it is determined whether or not the count value m is the number of the last shot area in the n-th row (here, the first row), for example, Judge based on the map. Here, since m = l, the determination here is denied, and the process proceeds to step 118 to increment the counter m by 1, and then proceeds to step 120, where the n-th row and the m-th shot area ( Here, various setting information required for exposure of the second shot area S (ie, the second shot) in the first row is transmitted to the synchronous control unit 80.

2

The transmission of the constant information is performed by the synchronous control unit 80 while the wafer stage WST and the reticle stage RST in the scanning direction immediately after the end of the exposure are performing the constant-speed overscan (post-setting) operation. Therefore, the synchronization control unit 80 can receive the various kinds of setting information sent without difficulty and store it in the internal memory. After transmitting the above setting information, main controller 50 synchronizes the movement of both stages RST and WST in the first mode (hereinafter abbreviated as “movement in the first mode”) in step 122. After instructing the control unit 80, the process returns to step 108 and waits for the completion of acceleration of both stages RST and WST to the target scanning speed.

 [0131] During the waiting state of step 108, the synchronous control unit 80 executes the movement operation in the first mode. Hereinafter, the movement operation in the first mode will be described in detail.

 [0132] <Moving operation in first mode>

 Here, as an example, as shown in FIG. 7, in the case of sequentially exposing the adjacent shot area, the first shot S, and the second shot S located on the same row, both shot areas between the shot areas are exposed.

 1 2

 The movement of the stage will be described.

In FIG. 8, a speed curve V (t) in the scanning direction of wafer stage WST related to the movement operation in the first mode is shown by a solid line, and a speed curve V (t) in the non-scanning direction is represented by yl xl Indicated by dotted lines. In FIG. 8, the horizontal axis represents time (t).

In the movement operation of the first mode, reticle stage RST moves according to a time change curve of a speed having a reciprocal multiple of the projection magnification of speed curve V (t), and therefore yl

 Detailed description is omitted.

 In the present embodiment, actually, based on a jerk, that is, an acceleration curve indicating a time change of acceleration, based on a jerk curve indicating a time change of a rate of change of acceleration (third-order differentiation with respect to time of position), A speed curve indicating the time change of the speed is sequentially calculated by the synchronous control unit 80, and a position command value is generated by the synchronous control unit 80 based on the speed curve. Then, the force at which the wafer stage WST is controlled by the wafer stage control unit 78 via the wafer drive system 48 in accordance with this command value.Below, in order to make the description easier to understand, the speed curve of FIG. The description is made with reference to the drawings.

 First, the scanning direction (scanning direction) will be considered. As described above, the shot area S

 1 At the end of exposure t (at this point, point P is at point A in Fig. 7)

 1

 At time t (= t + T) after one scan time T has elapsed, wafer stage WST decelerates (Fig. 7

 4 2 1 4

(Acceleration in the γ direction when the vehicle has a speed in the + γ direction). After deceleration starts, When the deceleration gradually increases (the absolute value of the acceleration in one Y direction increases), the deceleration becomes a predetermined constant value, and thereafter, the constant value is maintained for a predetermined time ΔΤ. However, the time from the deceleration start time t to the time T is the deceleration time.

 2 y5

 [0137] At this time, with respect to the point A (0, Ay) in FIG. 7 as a reference point, the wafer stage WST moves at a constant speed Vscan during the time T from the exposure end time t in the + Y direction as shown in FIG. Proceed to

 14

 After that, using the time point t after the passage of time T as the time reference point, follow the speed curve V (t) in Fig. 8.

 4 2 yl The speed further moves in the + Y direction for the time T at the speed. At the time t when this time T has elapsed, the branch point B (Bx, By) where the pre-scan starts for the shot area S as another y5 y5 3 section area

 2

 ) (See Figure 7).

 [0138] Thereafter, wafer stage WST moves speed in the Y direction with acceleration start point t as a time reference.

 Three

 It is accelerated for a time T at a speed according to the degree curve V (t).

 yl yl

 [0139] Acceleration is performed as described above, and at time t shown in FIG.

 Four

 ST is the target scanning speed V (where the minus sign means the speed in the Y direction)

 After that, after the time T as the synchronous control period of the reticle R and the wafer W, the exposure

 2

 Be started. The exposure time T is expressed as T = (shot area length Ly + illumination slit width w) / V.

 3 3 scans are performed.

 Next, a moving operation in the non-scanning direction (non-scanning direction) (stepping operation between shot areas) is considered. As shown in FIG. 8, immediately after the exposure of the shot area S is completed, the speed is increased.

 1 1

 Acceleration of wafer stage WST in the X direction is started according to degree curve V (t). Then xl

 The maximum speed V at the time T has elapsed since the start of acceleration (where the sign is X x5 xmax

 Directional speed). At this time, the X coordinate of the ueno and the stage WST is Bx, and the point P is at a point B (Bx, By) in FIG. Next, from that point, deceleration is started according to the speed curve V (t) (acceleration in the + X direction when the vehicle has a speed in the X direction) .xl

 . When the time τ elapses from the deceleration start time (acceleration end time), the deceleration ends and the speed xl

 The degree becomes 0 (that is, the movement in the non-scan direction is stopped). At this time, the X coordinate of the wafer stage is Lx (Lx is the stepping length), and point P has reached point C (Lx, Cy) in FIG.

[0141] That is, as shown in FIG. 8, the exposure direction of the previous shot area is When the time (τ + τ + τ) elapses from the end time t, the exposure for the next shot area is performed at the time t.

1 4 y5 yl 4

 Acceleration ends, but in the non-scan direction, as shown in Fig. 8, acceleration / deceleration ends when a time (T + T) elapses from the end of exposure of the previous shot area.

 Thus, assuming that τ = Τ and Τ = Τ hold, it can be seen that the stepping operation ends τ earlier than the synchronization control in yl xl y5 x5 2 at the settling time ス キ ャ ン in the scanning direction Τ. At this time

 Four

 Ueno, Stage The trajectory of WST is parabolic as shown in Fig.7.

When the stepping operation in the non-scanning direction ends earlier than the start of the synchronous control during the settling time in the scanning direction, the point at which the speed in the scanning direction becomes zero, that is, the deceleration ends and the exposure of the next shot area ends. The wafer stage is adjusted so that the X coordinate の of Β (Βχ, By) in FIG. 7, which is the point where acceleration for

 1 2 2

 The wafer stage control unit 78 and the synchronous control unit 80 force wafer stage WST The movement of each direction of X and Υ is controlled.

In the above-described stepping in the non-scanning direction, as is clear from FIG. 8, the speed V (t) is constantly changing in the non-scanning direction, and the wafer stage WST is always xl in the non-scanning direction.

 Have moved to. In other words, the wafer stage WST performs a stepping operation in parallel with the approach operation in the scan direction without stopping halfway. Therefore, the movement operation (including the scanning direction and the non-scanning direction) of the wafer stage WST between shot areas can be performed in almost the shortest time, and the throughput can be improved.

 [0144] By the way, since the pre-scan time includes the settling time T for causing the reticle R to completely follow the wafer W, the acceleration / deceleration control in the non-scan direction cannot be performed.

 2

 It is desirable that the end of the settling time T be as early as possible. Achieve this

 2

 Therefore, in the present embodiment, the wafer stage control unit 78 and the synchronous control unit 80 perform the same-speed overscan time T in the scan direction of the wafer stage WST following the end of exposure, as is clear from FIG. , Wafer stage WST in non-scan direction

 Four

 The moving operation is to be started, and the non-

 Four

Control is performed to terminate the acceleration / deceleration control that occurs in the scanning direction. That is, Since the stepping in the non-scanning direction is completed before the start of the synchronization control in the scanning direction, the synchronization control unit 80 performs only the synchronization control in the scanning direction during the settling time T.

 2

 I can concentrate on it. In addition, there is almost no effect of deceleration in the non-scanning direction during synchronous control.

, Synchronous settling time τ is shortened, and correspondingly, constant speed overscan time (after

 2

 (Pause) T can be shortened, and in this regard, throughput can be improved.

 Four

 Returning to the description of FIG. 5, while the movement operation in the first mode described above is being performed, main controller 50 terminates acceleration of both stages RST and WST in step 108 as described above. Waiting for you. When the movement operation in the first mode is completed, the determination in step 108 is affirmed. Thereafter, the processing (including the judgment) in the loop of steps 110 → 112 → 114 → 116 → 118 → 120 → 122 → 108 is repeated until the judgment in step 116 is affirmed. As a result, the second shot area of the n-th row (in this case, the second shot area of the first row (second shot S) to the last shot of the n-th row (the first row in this case))

 2

 Scanning exposure is performed for each yacht area (shot area S) by alternate scanning.

 7

 The pattern of the reticle R is sequentially transferred to those shot areas.

As described above, when the scanning exposure for the last shot area of the first row is completed, the determination in step 116 is affirmed, and the process proceeds to step 124.

In step 124, the counter m is initialized to 1, and the counter n is incremented by 1 (m ^ l, η ^ η + 1).

In the next step 126, it is determined whether or not the count value η is larger than the last line number 最終 by referring to the counter η. In this case, since η = 2, the determination in step 126 is denied, and the routine proceeds to step 128, where it is determined whether η is an even number. In this case, since η = 2, the determination here is affirmative, and the routine proceeds to step 130, at which various setting information necessary for exposure of the first shot area of the η-th row (the second row in this case) is obtained. After the transmission to the synchronous control unit 80, the process proceeds to step 132, where the synchronous control unit 80 is instructed to move both the stages RST and WST of the second mode (hereinafter, simply referred to as “movement of the second mode”). Thereafter, the process returns to step 108, and waits for completion of acceleration of both stages RST and WST to the target scanning speed. During the waiting state of step 108, the synchronous control unit 80 executes the movement operation in the second mode. Hereinafter, the movement operation in the second mode will be described. [0149] <Moving operation in second mode>

 The movement operation in the second mode is based on the last shot in an odd-numbered row (a row composed of a plurality of shot areas arranged in the non-scanning direction) in the movement trajectory of the point P between the different rows indicated by a dashed line in FIG. After the exposure of the area (referred to as “shot area A” for convenience) and before the start of the exposure of the first shot area (referred to as “shot area B” for convenience) in a different row (next row), FIG. Between the shot area S and the shot area S, and between the shot area S and the shot area S.

 7 8 27 28, between shot area S and shot area S, between shot area S and shot area S

 49 50 69 70 is the movement operation of both stages.

In FIG. 9, a speed curve V (t) in the scanning direction of wafer stage WST related to the movement operation in the second mode is shown by a solid line, and a speed curve V (t) in the non-scanning direction is represented by y2 × 2. Indicated by dotted lines. In FIG. 9, the horizontal axis represents time (t).

[0151] In the movement operation between different rows, such as the movement operation in the second mode, it is necessary to match the acceleration condition before the wafer scan exposure and the acceleration condition before the reticle scan, so that the wafer stage starts the exposure. Prior to this, it is necessary to stop not only in the non-scan direction but also in the scan direction.

[0152] Therefore, as a sequence of the movement operation of the wafer stage WST between the shot areas A and B in the scanning direction, as shown in the velocity curve V (t) shown in FIG.

 When the exposure of the cut area A is completed t When the constant overscan time T elapses

 11 4

 At a point t (= t + T), the wafer stage WST starts decelerating. And at the time of further deceleration

12 11 4

 At time t after the interval T has elapsed, deceleration after exposure ends, and y5 13

 The position corresponding to the scanning start position is reached. At this time t, Y follows the speed curve V (t)

 13 y2

 Stepping in the axial direction (hereinafter, appropriately referred to as “Y step”) is started. The stepping in the Υ-axis direction is performed by moving the wafer stage WST in the Υ-axis direction according to a speed change curve similar to the above-described step change between shot regions in the non-scanning direction. In the case of FIG. 9, wafer stage WST starts accelerating in the Y direction at time t.

 13

 Then, after the time T has elapsed after the start of the stepping in the Y-axis direction, the step in the Y-axis direction is performed at time t.

 6 14

The wafer stage WST stops moving in the scanning direction for a time ΔΤ1 from this point. Then, at the time t, the time t (= t + ΔΤ1) Then, the acceleration for exposing the shot area B is started.

In the movement operation in the second mode, reticle stage RST may stop moving to the scanning start position when wafer stage WST moves to the deceleration end position after exposure for shot area A described above. In this case, it is sufficient that the wafer stage WST is stopped until the acceleration before the exposure in the shot area B is started. In the moving operation in the second mode, the post-exposure period after the exposure of the shot area A may be eliminated.

 [0154] The movement operation of wafer stage WST in the non-scanning direction is started at time t after the exposure of shot area A is completed, similarly to the movement operation in the first mode described above.

 11

 (τ End.

 x5 + τ xl)

 As is apparent from FIG. 6, between the shot areas S and the shot areas S,

 27 28

 In the movement operation in the second mode between the region S and the shot region S, the wafer stage WST

49 50

 Is maintained at a constant coordinate position in the non-scan direction.

Returning to the description of FIG. 5, while the above-described second mode movement operation is being performed, main controller 50 ends acceleration of both stages RST and WST in step 108 as described above. Waiting for you. When the movement operation in the second mode is completed, the determination in step 108 is affirmed. Thereafter, the processing (including the judgment) in the loop of steps 110 → 112 → 114 → 116 → 118 → 120 → 122 → 108 is repeated until the judgment in step 116 is affirmed. As a result, the first shot area S in the n-th row (in this case, the second row) is

 8 for each of the last shot areas s

 16

 Then, the pattern of the reticle R is sequentially transferred to those shot areas.

[0157] In this way, when the scanning exposure for the last shot area S in the second row is completed,

 16

 If the determination in step 116 is affirmative, the process proceeds to step 124.

In step 124, the counter m is initialized to 1, and the counter n is incremented by 1 (m ^ l, η ^ η + 1).

In the next step 126, it is determined whether or not the count value η is larger than the last line number Ν by referring to the counter η. In this case, since η = 3, the determination in step 126 is denied, and the routine proceeds to step 128, where it is determined whether η is an even number. In this case, η Therefore, the determination at this step is denied, and the routine proceeds to step 134, at which various setting information necessary for exposure of the first shot area in the n-th row (in this case, the third row) is transmitted to the synchronous control unit 80. After the transmission to the synchronous control unit 80, the process proceeds to step 136 to instruct the synchronous control unit 80 to move both the stages RST and WST of the third mode (hereinafter abbreviated as “movement of the third mode”). Then, wait until both stages RST and WST finish accelerating to the target scanning speed. During the waiting state in step 108, the synchronous control unit 80 executes the third mode movement operation. Hereinafter, the moving operation in the third mode will be described.

[0160] <Moving operation in 3rd mode>

 The movement operation in the third mode is performed after the exposure of the last shot area (referred to as “shot area C” for convenience) in the even-numbered row of the movement trajectory of the point P between the different rows indicated by the dashed line in FIG. Before the start of exposure of the first shot area (referred to as “shot area D” for convenience) in a different row (next row), specifically, between the shot areas S in FIG.

 16 17 Performed between the yacht area S and the shot area S, and between the shot area S and the shot area S.

 38 39 60 61

 Movement of the two stages.

In FIG. 10, a speed curve V (t) in the scanning direction of wafer stage WST related to the movement operation in the third mode is shown by a solid line, and a speed curve V (t) in the non-scanning direction is represented by y3 × 3. Indicated by dotted lines. In FIG. 10, the horizontal axis represents time (t).

[0162] Also in this third mode of moving operation, the acceleration condition before the wafer scan exposure and the acceleration condition before the reticle scan need to be matched. It is necessary to stop not only in the direction but also in the scanning direction.

 [0163] For this reason, the sequence of the movement operation of the wafer stage WST between the shot areas C and D in the scanning direction includes the y3 as shown in the speed curve V (t) shown in FIG.

 At the time when the exposure of the yacht area C is completed, t is almost time (T + T).

 21 x5 xl 22 Eno, stage WST starts to decelerate. Then, at the point of time ty523 at which the deceleration time T has further elapsed, the deceleration after the exposure is completed, and the scan area D reaches the scanning start position for exposure. At this time t force time ΔΤ2, the wafer stage WST stops moving in the scanning direction.

 twenty three

At time t (= t + ΔΤ2) after the time t force time ΔΤ2 has elapsed, Acceleration is started.

 In the movement operation in the third mode, reticle stage RST starts deceleration after exposure to shot area C described above, and scan opening y5 at time T after the start of the deceleration.

 Since the movement to the starting position can be completed, in this case, it is sufficient that the wafer stage WST is stopped until acceleration of the wafer stage WST before exposure to the shot area D is started.

The movement operation of wafer stage WST in the non-scanning direction is started at time t after the exposure of shot area C is completed, as in the above-described movement operation in the first mode.

 11

 τ + τ) is terminated at the time point.

 x5 xl

 As is apparent from FIG. 6, the third mode between the shot areas S

 38 39

 In the moving operation, the wafer stage WST is maintained at a constant coordinate position in the non-scan direction.

 Returning to the description of FIG. 5, while the above-described third mode movement operation is being performed by synchronous control unit 80, main controller 50 causes both stages RST and WST to go through step 108 as described above. Waiting for acceleration to end. When the movement operation in the third mode is completed, the determination in step 108 is affirmed. Thereafter, the first shot area in the third row (shot area S in FIG. 6) to the last shot area S (S) in the last row (Nth row)

 Until the exposure of 17 76 is completed, the processing of step 108 and subsequent steps is repeated.

[0168] In this manner, the scanning exposure of the shot area on the wafer W, the stepping operation between the shot areas, and the force are repeatedly performed by the full alternate scan, and the reticle for the shot area S, which is the final shot area on the wafer W, is repeated. When the transfer of the R pattern is completed, the determination in step 126 is affirmed, and the series of processing of this routine is completed.

In the case of the present embodiment, scan exposure is performed sequentially and alternately along a path as shown in FIG. In this case, since the total exposure rows are even rows, the exposure is lower than the shot area S in the lower left of FIG.

1 Starts, the first line is exposed in the order of left → right, the next line is alternately stepped from right to left, and finally the exposure of the upper left shot area S is completed. At this point, when the wafer stage WST moves to a predetermined wafer replacement position, if the operation is repeated, the sequence becomes as follows. At the time of the above-described alternate scan, between the adjacent shot areas on the same row, the above-described efficient movement control between the shot areas of the wafer stage WST is performed. [0170] Although the description is before and after, in the exposure apparatus 10 of the present embodiment, the movement of the wafer stage in the movement operation of the first mode, the second mode, and the third mode, and the movement of the wafer stage in the movement operation of the first mode Learning control is repeatedly performed in advance for reticle stage RST follow-up control with respect to WST, and a correction value group obtained as a result of the learning control is used for the wafer stage WST and reticle during the actual exposure operation. Stage RST position is corrected.

 [0171] Hereinafter, the repetitive learning control in the present embodiment will be described in more detail.

 In exposure apparatus 10 of the present embodiment, for each of the above-described first mode, second mode, and third mode movement operations, the position error with respect to the target position of wafer stage WST is corrected in advance by iterative learning control. Are acquired and stored in the corresponding buffer memory. As for the movement operation in the first mode, a correction value group for correcting a tracking error of reticle stage RST with respect to wafer stage WST is acquired and stored in a corresponding buffer memory.

 [0173] First, acquisition of a correction value group related to the movement operation in the first mode will be described. The acquisition of the correction value group relating to the movement operation in the first mode is performed in the following procedure.

 A. First, in response to an instruction from main controller 50, switch SW1 in FIG. 3 is set to “ON” and switch SW2 is set to “OFF” by synchronous control unit 80. Then, from the synchronous control unit 80, the ueno and the stage corresponding to the speed curve V (t) (0≤t≤t) shown in FIG.

 yi 3

 A position command in the Y axis direction of WST is output. Thus, wafer stage control unit 78 controls wafer stage system Wp, and performs a normal scan in which the + Y direction of wafer stage WST is set as the scan direction. During the normal scan of the wafer stage WST, at a predetermined sampling interval, the ILC controller 58 calculates a correction value for ascending the positional deviation, which is the difference between the target position of the wafer stage WST in the Y-axis direction and its current position, to zero. It is calculated sequentially. Then, a series of time series data composed of the sequentially calculated correction value group force is stored in the corresponding buffer memory of the internal memory of the synchronous control unit 80.

At this time, for example, the synchronous control unit 80 inputs the measurement value (R 1, R 2, R 3) of the reticle interferometer 30 as a position command to the subtractor 62, or (R ′, R ', R') =

 X L R X L R

(0, 0, 0) is input. Therefore, in the former case, reticle stage RST In the latter case, the reticle stage RST returns to the home position and then stops at that position.

[0176] Next, synchronous control unit 80 outputs a position command corresponding to velocity curve V (t) (t≤t≤t) in FIG. 8 such that the scanning direction of wafer stage WST is opposite to the upward direction. This much yl 3 5

 Wafer stage control unit 78 controls wafer stage system Wp in response to the placement command. Then, the correction value group in the negative scan of the stage and the stage WST is stored in the corresponding buffer memory of the internal memory of the synchronous control unit 80 in the same manner as described above.

[0177] B. Next, the wafer stage yl xl 5 corresponding to the velocity curves V (t) and V (t) (0≤t≤t) shown in FIG.

 The position commands of the WST in the Y-axis direction and the X-axis direction are input from the synchronous control unit 80 to the subtractor 52. Accordingly, the wafer stage control unit 78 follows the same movement trajectory (see FIG. 7) as in the continuous exposure of the shot area S and the shot area S described above.

1 2

 The wafer stage WST is moved. At this time, in the synchronous control unit 80, the respective correction values stored in the corresponding buffer memory in the internal memory are added to the third input terminal of the adder 54 in synchronization with the sampling clock. The position of the wafer stage WST in the Υ axis direction is corrected. Further, during the movement of the wafer stage WST along the path shown in FIG. 7, at a predetermined sampling interval, the ILC controller 58 determines the difference between the target position of the stage WST and its current position in the X-axis direction. Correction values for causing the position deviation to gradually approach zero are sequentially calculated. Then, a series of time-series data including the sequentially calculated correction value group power is stored in the corresponding buffer memory in the internal memory of the synchronous control unit 80.

 Next, the speed curve xl in the non-scan direction obtained by inverting the speed curve V (t) shown in FIG.

 Yl and the position of the stage WST in the Y-axis direction and the X-axis direction corresponding to the velocity curve V (t) yl

The position command is input from the synchronous control unit 80 to the subtractor 52. Thereby, wafer stage WST is moved by wafer stage control unit 78 according to a movement trajectory that reverses the movement trajectory of FIG. Also at this time, the synchronous control unit 80 corrects the position of the wafer stage in the γ-axis direction in the same manner as described above. Further, during the movement of wafer stage WST, at predetermined sampling intervals, ILC controller 58 gradually reduces the positional deviation, which is the difference between the target position of wafer stage WST in the X-axis direction and its current position, to zero. Correction values to be brought closer are sequentially calculated. Then, a series of time-series data including the sequentially calculated correction value group force is stored in the corresponding buffer memory of the internal memory of the synchronization control unit 80.

 C. Next, in response to an instruction from main controller 50, switch SW1 in FIG. 3 is set to “OFF” and switch SW2 is set to “ON” by synchronous control unit 80. Then, from the synchronous control unit 80, the wafer stage WST corresponding to the speed curve V (t) shown in FIG.

 yi

 A position command in the Y-axis direction is output. Thus, wafer stage system Wp is controlled by wafer stage control unit 78, and a normal scan of wafer stage WST is performed. At this time, the synchronous control unit 80 first applies the corresponding correction values stored in the corresponding buffer memory of the internal memory to the third input terminal of the adder 54 in synchronization with the sampling clock, and the wafer stage Correct the position of the WST in the Y-axis direction.

[0180] In parallel with the above-described normal scan of wafer stage WST, synchronous control unit 80 outputs the target position (R ', R '

 X L

 , R,). As a result, the reticle stage control unit 33

R

 The stage system Rp is controlled, thereby performing a negative scan following the positive scan of the wafer stage WST with the scan direction in the Y direction of the reticle stage RST. During the negative scan of the reticle stage RST, at a predetermined sampling interval, the ILC controller 68 sets a correction value for asymptotically reducing the position deviation, which is the difference between the target position of the reticle stage RST in the Y-axis direction and its current position, to zero. It is calculated sequentially. Then, a series of time-series data including the sequentially calculated correction value group force is stored in the corresponding buffer memory of the internal memory of the synchronization control unit 80.

[0181] Next, synchronous control unit 80 outputs a position command corresponding to speed curve V (t) in Fig. 8 such that the scanning direction of wafer stage WST is opposite to the upward direction, and the position command is

 yi

 In response, the wafer stage system Wp is controlled by the stage control unit 78 in the same manner as described above, and at the same time, the target position (R ′) from the synchronous control unit 80 is controlled.

 X

 , R ′, R ′) are input to the subtractor 62 as a position command. As a result, the reticle

The correction value group in the positive scan of the stage RST is stored in the corresponding buffer memory of the internal memory of the synchronous control unit 80 in the same manner as described above. [0182] As described above, the iterative learning in the case of the movement operation in the first mode is completed, and the correction value group for the position deviation during the scan operation of wafer stage WST (positive Scan and negative scan), and a set of position deviation correction values during stepping operation in the X-axis direction (stepping in the X direction (hereinafter referred to as “negative step”)), + X direction Correction value group corresponding to stepping to the reticle stage (hereinafter referred to as “positive direction step”), and correction value group of the tracking error (synchronization error) for the reticle stage RST and stage WST (positive scan, (Including the correction value group corresponding to each negative scan.) Force Stored in the corresponding buffer memory of the internal memory of the synchronous control unit 80. .

 [0183] Regarding the movement operation in the second mode, the velocity curve V (t) in FIG.

 The velocity curve (described as one V (t)), and the velocity curve V (t) in FIG. 9 and its reversal y2 x2

 Using the velocity curves (described as -V (t)), learning is performed repeatedly in the same procedure as A. and B. in the first movement mode described above. Correction value groups corresponding to (X step in the direction), (Y step in the positive direction and X step in the negative direction), (Y step in the negative direction and X step in the positive direction) and (Y step in the negative direction and X step in the negative direction) are synchronized. It is stored in the corresponding buffer memory of the internal memory of the unit 80.

[0184] Regarding the movement operation in the third mode, the velocity curve Vy (t) in Fig. 10 and the velocity curve obtained by inverting the velocity curve (described as -V (t)), and the velocity curve V (t ) And its sign y3 x3

 Using the inverted velocity curves (described as -V (t)), the x3

 In the case, learning is performed repeatedly in the same procedure as A. and B., (Positive direction X step after positive scan), (Positive direction step after positive scan), (Positive direction step after negative scan) and (Negative scan) The correction value groups respectively corresponding to the rear negative direction step) are stored in the corresponding buffer memory of the internal memory of the synchronous control unit 80.

In the actual exposure, in steps 122, 132, and 136 of the flowchart described above, the movement of each stage in each mode is controlled by the wafer stage control according to the position command from the synchronization control unit 80. Forces executed by the system 92 and the reticle stage control system 94 At this time, the switches SW1 and SW2 are both set to the OFF state. Therefore, when performing any one of the first mode movement operation, the second mode movement operation, and the third mode movement operation, Even in this case, the synchronous control unit 80 controls each correction value that constitutes a correction value group in the movement direction (positive / negative direction of each of the scan, Y step, and X step) of the corresponding wafer stage WST in the corresponding mode in the internal memory. Are sequentially input to the third input terminals of the adders 54 and 64 at timings corresponding to the acquisition timings of the respective correction values during repetitive learning in synchronization with the sampling clock. Thereby, the position deviation of both stages is performed such that the position deviation of wafer stage WST and the position deviation of reticle stage RST (following error with respect to wafer stage WST (synchronization error of both stages)) approach zero. .

 As described above in detail, according to exposure apparatus 10 of the present embodiment, at the time of exposure, main controller 50 disconnects ILC controller 58 from wafer stage control system 92, and When the setting conditions for setting the ILC controller 68 to the disconnected state with respect to the reticle stage control system 94 are set, the switches SW1 and SW2 are both turned OFF by the synchronous control control unit 80 in accordance with the set conditions. The settings are made according to the setting conditions. In this state, the processing according to the above-described flowchart is performed. For example, when the movement operation in the first mode is instructed from the main controller 50, the wafer stage control is performed based on the position command of the synchronous control unit 80. The reticle stage RST and the wafer stage WST are moved synchronously by the system 92 and the reticle stage control system 94, and during this synchronous movement, the pattern of the reticle R illuminated by the illumination light IL Each is transferred to the shot area (see step 110—step 114).

[0187] During the synchronous movement between reticle stage RST and wafer stage WST, the synchronous control unit 80 provides the wafer stage control system 92 with the corresponding correction value group ( (Referred to as the first correction value group) are sequentially input as correction values for the position deviation, and the corresponding correction values obtained in advance by the ILC controller 66 are supplied to the reticle stage control system 94. A group (referred to as a second correction value group) is sequentially input as a correction value of the position deviation. This allows the wafer stage control system 92 to perform the position correction of the wafer stage WST such that the position deviation of the wafer stage WST gradually approaches zero by using the first correction value group. According to 94, the position deviation of reticle stage RST (the tracking error of reticle stage RST with respect to wafer stage WST, ie, the synchronization error between both stages RST and WST) is calculated using the second correction value group. The position of the reticle stage RST is corrected so that the value of) approaches zero.

 As described above, in the exposure apparatus 10 of the present embodiment, the scanning exposure is performed in a state where the synchronization error between the two stages RST and WST is effectively reduced, and the sliding force is also reduced in the first and second stages. Since the correction value group is obtained by the iterative learning control performed in advance as described above, the synchronization error between the two stages RST and WST unique to the exposure apparatus 10 can be reliably reduced. This makes it possible to transfer the pattern formed on the reticle R onto the wafer W with high accuracy.

 Further, in the present embodiment, prior to the actual exposure operation, for example, as described in the procedure B. during the operation of acquiring the correction value group related to the movement operation in the first mode, the exposure for one shot area is performed. A predetermined path (see FIG. 7) intersecting both in the scanning direction (scanning direction) and the non-scanning direction perpendicular to the scanning direction (scanning direction) in the same manner as in the movement operation between shot areas performed between and the exposure for the next shot area. (See the U-shaped movement trajectory shown.) While moving the wafer stage WST, the position deviation, which is the difference between the target position in the non-scanning direction (wafer stage in the X-axis direction) and its current position, is asymptotically reduced to zero. It is performed by the synchronous learning control unit 80 and the wafer stage control unit 78 to obtain a correction value group to be obtained (a correction value group relating to X ^ steps).

 [0190] The correction value group for the step obtained in this case is different from the correction value group obtained by the repetitive learning control in which the wafer stage WST is moved only in the non-scanning direction, and is different from the correction value group for the ueno and the stage WST in the scanning direction. In consideration of the effect of the movement on the movement in the non-scanning direction, the movement value (stepping) between the actual shot areas of the wafer stage WST is considered, and a correction value group relating to X ^ step is obtained. .

Then, during the actual exposure operation, the synchronous control unit 80 corrects the actual position while correcting the position of the wafer stage WST in the non-scanning direction in consideration of the correction value group relating to the X step. The movement between shot areas is performed, and the reticle stage RST and the wafer stage WST for the scanning exposure are moved synchronously in the scanning direction before and after the movement between shot areas, and the reticle pattern is moved to the wafer. Copied to each shot area on W. In this case, when the movement operation between the shot areas of the wafer stage WST is completed and the scanning exposure for the next shot area is started, the movement operation between the shot areas is performed. The positional deviation of the wafer stage WST in the non-scanning direction (X-axis direction) is almost certainly corrected.

In this state, scanning exposure is performed. Therefore, the pattern is accurately applied to each shot area on the wafer W by the scanning exposure performed in a state where there is almost no displacement between the two stages RST and WST in the non-scanning direction due to the movement operation between the partitioned areas of the object stage. (For example, superposition accuracy), it becomes possible to transfer.

 In the present embodiment, when the wafer stage WST is moved along a predetermined path in order to acquire a correction value group relating to the X step, the synchronization control unit 80 controls the target of the wafer stage WST in the scanning direction. The position of the wafer stage WST in the scanning direction is corrected in consideration of a group of correction values for the scanning that makes the position deviation, which is the difference between the position and the current position, asymptotic to zero. As a result, the correction value group relating to the step not only takes into account the effect of the movement of the wafer stage WST in the scanning direction on the movement in the non-scanning direction, but also reduces the position error in the scanning direction. The effect on X steps is removed.

 [0193] In this case, the correction value group relating to scanning is a force that can be obtained in advance by an experiment (including simulation), etc. In this embodiment, as described in the above-mentioned procedure A. Then, similarly to the synchronous movement at the time of the exposure, the correction value group relating to the scan is repeatedly obtained by learning control while moving the ueno and the stage WST in the running direction. For this reason, it is possible to reliably remove the influence of the positional error in the scanning direction on the step in the stepping between the shot areas of the WST of the wafer stage specific to the exposure apparatus 10 on the step.

 According to exposure apparatus 10 of the present embodiment, stage control system 90 for controlling wafer stage WST and reticle stage RST (more precisely, synchronous control unit 80 constituting stage control system 90) Operating conditions (e.g., the above-mentioned first mode-third mode, scan, or Y) selected from a plurality of correction value groups for ascending the position deviation, which is the difference between the target position and the current position of the stage WST, to zero. The position of the wafer stage WST is corrected based on a correction value group corresponding to the positive and negative directions of the step and the X step).

[0195] In the exposure apparatus 10 as described above, a plurality of operations are performed as operating conditions of the wafer stage WST. Conditions are set, and for each of the plurality of operating conditions, a plurality of correction value groups for ascending the position deviation, which is the difference between the target position and the current position of the wafer stage WST, to zero are repeatedly obtained in advance by learning control. I have.

 [0196] In the actual exposure process, the synchronous control unit 80 constituting the stage control system 90 outputs a plurality of correction value groups corresponding to the operating conditions at that time (specified (set) by the main controller 50). The wafer stage WST is controlled in accordance with the operating conditions while selecting the correction value group and correcting the position of the wafer stage WST based on the correction value group.

 Thus, regardless of the operating conditions, it becomes possible to control wafer stage WST in accordance with the operating conditions while correcting the position of wafer stage WST.

 [0198] Further, a stage control system 90 for controlling reticle stage RST and wafer stage WST performs both stages RST and WST in the scanning direction between the exposure of one shot area and the exposure of the next shot area. When executing the movement sequence of the two stages RST and WST that stop and stop, for example, when performing the movement operation of the second mode or the movement operation of the third mode described above, a certain period of time has elapsed from the end of exposure of one shot area. After the lapse, acceleration of both stages RST and WST is started. For example, in the case of the above-described movement operation in the second mode, the synchronous control unit 80 constituting the stage control system 90 manages the lapse of a fixed time (T + T + T + ΔΤ1) at the end of the exposure of the shot area A. And that certain time has passed

11 4 y5 6

 Later, both stages RST and WST will start accelerating. For example, in the case of the above-described third mode movement operation, the synchronous control unit 80 constituting the stage control system 90 waits for a predetermined time (T + T + T + ΔΤ2) from the exposure end time t of the shot area C.

 21 x5 xl y5

 After a certain period of time, the acceleration of both stages RST and WST is started.

 [0199] For this reason, the stop time of both stages is constant (normally, the deceleration time (T) is constant y5

Vi) Vibration generated when both stages are decelerated after the exposure of the shot area is attenuated during stoppage, but the reproducibility of the attenuation of the vibration can be increased. As a result, at the start of acceleration, the same vibration (vibration within an allowable level) is always left! /, So that the wafer stage WST and reticle stage RST are repeated. When learning control is employed, the effect of the repetitive learning control can be improved. repetition Learning control is a force that is effective against phenomena such as reproducible vibration.

 [0200] In the above embodiment, prior to exposure, the synchronous control unit 80 force switch SW1 is turned "ON" and the ILC controller 58 is turned on before acquiring the correction value group relating to the movement operation in the first mode. While connected to the wafer stage control system 92, with the switch SW2 set to `` OFFJ '' and the reticle stage RST stopped at a predetermined position, the movement operation of the wafer stage WST in the first mode by the wafer stage control unit 78 and the Then, a repetitive learning control is performed, and a correction value group relating to the movement operation of the wafer stage WST in the first mode is stored in the corresponding buffer memory of the internal memory of the synchronous control unit 80 (see the procedures A. and Then, as step C., the synchronous control unit 80 turns off the switch SW1 and turns on the switch SW2 to turn on the ILC controller 58. No, the reticle stage RST and the wafer stage WST are synchronously moved by the stage control system 90, that is, the ILC controller 68 is disconnected from the stage control system 92, and the ILC controller 68 is connected to the reticle stage control system 94. Following control of reticle stage RST to wafer stage WST is performed. At this time, the data constituting the corresponding correction value group obtained in advance by the ILC controller 58 are sequentially input to the wafer stage control system 92 as correction values of the position deviation by the synchronous control unit 80. Then, the wafer stage control system 92 performs the position correction of the wafer stage WST such that the position deviation of the wafer stage WST approaches zero using the group of correction values. In addition, during the follow-up control of the reticle stage RST to the wafer stage WST, in parallel with the position correction of the wafer stage WST, a correction value group acquired by the learning control by the ILC controller 68 by the synchronous control unit 80 is stored by the synchronous control unit 80. .

 [0201] That is, in the above-described embodiment, a case has been described in which a correction value group for correcting the positional deviation of the wafer stage WST and the reticle stage RST is acquired through such a step. Of course, it is not limited.

[0202] For example, prior to exposure, the synchronous control unit 80 force switches SW1 and SW2 are simultaneously turned ON, the ILC controller 58 is connected to the wafer stage control system 92, and the ILC controller 68 is controlled to the reticle stage. Connect to system 94. Then, in this state, the stage control system 90 connects the reticle stage RST to the wafer stage WST. Synchronous movement, that is, tracking control of reticle stage RST to wafer stage WST may be performed. When the reticle stage RST is controlled to follow the wafer stage WST, the synchronous control unit 80 corrects the position deviation of the wafer stage WST acquired by the ILC controller 58 through iterative learning control during the follow-up control of the reticle stage RST. , And a correction value for correcting the position deviation of the reticle stage RST obtained by the repetitive learning control by the ILC controller 68 are stored in the corresponding buffer memories of the internal memory. That is, a group of correction values for correcting the position deviation of wafer stage WST and a group of correction values for correcting the position deviation of reticle stage RST may be obtained at one time.

 [0203] Even in the case where power is applied, the obtained correction value groups are used at the time of exposure in the same manner as in the above embodiment, so that the position deviation of the wafer stage WST and the reticle can be obtained in the same manner as in the above embodiment. It is possible to correct the position of both stages such that the position deviation of the stage RST (following error with respect to the wafer stage WST (synchronization error between both stages)) approaches zero.

 In the above embodiment, a group of correction values individually corresponding to the movement operation in the first mode-third mode (a plurality of operation sequences of the wafer stage WST) is acquired in advance by the repetitive learning control described above. It should be noted that, during exposure, a stage control system 90 that controls both stages WST and RST performs a plurality of corrections to ascend the position deviation, which is the difference between the target position of the wafer stage WST and the current position, to zero. The case where the position of wafer stage WST is corrected based on the correction value group corresponding to the operating condition selected from the value group has been described. The method of classifying the operating conditions under which the correction value groups are prepared is not limited to this, and the plurality of correction value groups may be used in a wafer stage when continuously exposing a plurality of shot areas in the same row. A correction value group individually corresponding to the operation pattern of the wafer and the operation pattern of the wafer stage when continuously exposing a plurality of shot areas in different rows may be included. In addition, if the main purpose is to correct the position of the wafer stage based on the correction value group corresponding to the operating condition, the correction value group is operated in advance by a simulation or the like that is not a repetitive learning control. It may be obtained for each condition.

[0205] In the above embodiment, the case where the learning control is repeatedly performed by moving the stage before performing exposure on the wafer has been described. However, the above-described learning control is performed while performing exposure. Alternatively, the correction value group may be stored. The correction value group obtained by the repetitive learning control is, for example, the power that can be individually acquired before shipment of each exposure apparatus as information unique to the exposure apparatus and stored in the synchronous control unit. In addition, the learning control is repeatedly performed, and the correction value group at that time may be stored.

Further, as a reticle stage or wafer stage of an exposure apparatus, a stage composed of a coarse movement stage and a fine movement stage (hereinafter, referred to as a “coarse / fine movement type stage”) is known. In this case, the fine movement stage holds the reticle or wafer, and is a force that can be moved with a relatively short stroke. Its position controllability (including positioning accuracy) is configured to be highly accurate and responsive. . The coarse movement stage is configured so that the fine movement stage can be moved over a relatively long distance. The present invention can also be applied to an exposure apparatus having such a coarse / fine movement stage. Even in the coarse / fine movement stage, the control system for the coarse movement stage and the fine movement stage can both be configured as a feedback control system based on the position command value. May be provided. However, only the control system of the fine movement stage that holds the reticle or wafer, which is the target of final position control (including positioning), may have the learning control function repeatedly. In either case, it is possible to perform tracking control such that the reticle follows the wafer as in the above embodiment. For example, when the reticle stage is a coarse / fine movement stage, the control system of the reticle stage described in the above embodiment can be used as the control system of the reticle fine movement stage. In this case, by setting the target position (position command value) for the reticle coarse movement stage to a value such that the reticle coarse movement stage is located near the reticle fine movement stage, the reticle fine movement stage can be moved to the wafer stage. It is possible to perform feedback control of a position independent of the wafer stage instead of following control. When both the reticle stage and the wafer stage are coarse and fine movement stages, the reticle stage control system described in the above embodiment is used as the reticle fine movement stage control system, and the wafer stage control system described in the above embodiment is used. May be used as a control system for the wafer fine movement stage. In this case, the reticle fine movement stage is set so that tracking control to the wafer fine movement stage is performed. In the above embodiment, ultraviolet light having a wavelength of 100 nm or more, such as KrF excimer laser light, ArF excimer laser light or F laser light (wavelength 157 η), is used as exposure illumination light.

 2

 The force described for the case of using m) etc. The present invention is not limited to this. For example, far ultraviolet (DUV) light belonging to the same deep ultraviolet region as the KrF excimer laser such as g-line and i-line can also be used. Note that a harmonic of a YAG laser may be used.

 [0208] Further, a DFB semiconductor laser or a fiber laser is used to amplify an oscillated single-wavelength laser in the infrared or visible region with, for example, an erbium (or both erbium and ytterbium) force S-doped fiber amplifier, and to perform nonlinear amplification. It is also possible to use harmonics whose wavelength has been converted to ultraviolet light using an optical crystal. As the single-wavelength oscillation laser, for example, an ittel beam-doped fiber laser can be used.

 [0209] In the exposure apparatus of the above embodiment, the illumination light for exposure is not limited to light having a wavelength of lOOnm or more, and of course light having a wavelength of less than lOOnm may be used. For example, recently, in order to expose a pattern of 70 nm or less, EUV (Extreme Ultraviolet) light in the soft X-ray region (for example, a wavelength region of 5 to 15 nm) is generated using a SOR or a plasma laser as a light source, and the exposure is performed. An EUV exposure tool using an all-reflection reduction optical system designed under a wavelength (for example, 13.5 nm) and a reflective mask is being developed. In this apparatus, a configuration in which scan exposure is performed by synchronously scanning the mask and the wafer using arc illumination can be considered, so that a powerful apparatus is also included in the scope of the present invention.

 [0210] The present invention can also be applied to an exposure apparatus that uses a charged particle beam such as an electron beam or an ion beam. For example, as an electron beam exposure apparatus, for example, a circuit pattern is decomposed and formed into a number of subfields of about 250 nm square separated from each other on a mask, and the electron beam is sequentially shifted in a first direction on the mask, and In synchronism with the movement of the mask in the second direction perpendicular to the direction, the wafer is moved relative to the electron optical system that reduces and projects the decomposition pattern, and the reduced image of the decomposition pattern is joined on the wafer to form a composite pattern. Can be used.

[0211] By the way, in the above embodiment, the power described in the case where the present invention is applied to the step-and-scan type reduction projection exposure apparatus (scanning stepper), for example, the mirror projection aligner, the proximity type exposure Equipment (eg X-rays The present invention can also be applied to a scanning type X-ray exposure apparatus that integrally moves a mask and a wafer relative to an arcuate illumination area.

 [0212] Further, as the projection optical system, not only a reduction system but also an equal magnification system or an enlargement system (for example, an exposure apparatus for manufacturing a liquid crystal display) may be used. Further, the projection optical system may be any one of a refraction system, a reflection system, and a catadioptric system. The types of glass materials and coating materials that can be used for optical elements (especially refraction elements) are limited by the wavelength of the illumination light for exposure, and the maximum aperture that can be manufactured differs for each glass material. In consideration of the exposure wavelength and its wavelength width (spectral half width) determined from the above, and the field size and numerical aperture of the projection optical system, etc., one of the refraction, reflection, and catadioptric systems should be selected. Become.

 [0213] In general, when the exposure wavelength is about 190 nm or more, synthetic quartz and fluorite can be used as the glass material, so that not only the reflection system and the catadioptric system but also the refractive system is relatively easy. Can be adopted. In addition, in the case of vacuum ultraviolet light having a wavelength of about 200 nm or less, a refracting system can be used depending on the narrowed wavelength width. In particular, when the wavelength is about 190 ηm or less, an appropriate material other than fluorite is used as a glass material. It is advantageous to employ a reflection system or a catadioptric system, since it is difficult to narrow the wavelength band and it becomes difficult. Furthermore, in EUV light, a reflective system is used in which only a plurality of (for example, about 3 to 6) reflective elements are powerful. Note that an electron beam exposure apparatus uses an electron lens and an electron optical system that acts as a deflector. In the case of the illumination light for exposure in the vacuum ultraviolet region, a force that fills the optical path with a gas that reduces the attenuation (for example, an inert gas such as nitrogen or helium) or the optical path is set to vacuum, and the optical path for EUV light or an electron beam is set to vacuum. Apply vacuum.

 [0214] Further, a part of the present invention (at least not including a mask as a constituent requirement) can also be applied to an exposure apparatus that exposes a predetermined pattern directly on a wafer without using a mask (reticle). It is possible.

[0215] Furthermore, the present invention relates to an exposure apparatus for liquid crystal that transfers a liquid crystal display element pattern onto a square glass plate that can be formed only by an exposure apparatus used for manufacturing a semiconductor element, and a plasma display and an organic EL. Exposure equipment for manufacturing display devices, thin-film magnetic heads, imaging devices (such as CCD), micromachines, DNA chips, etc., as well as masks or lasers. The present invention can be widely applied to an exposure apparatus used for manufacturing a chickle. In addition, in order to manufacture a reticle or mask used in a light exposure device that can be connected only with micro devices such as semiconductor elements, EUV exposure devices, proximity type X-ray exposure devices, and electron beam exposure devices, glass substrates or The present invention is also applicable to an exposure apparatus that transfers a circuit pattern onto a silicon wafer or the like. Here, in an exposure apparatus using an optical exposure apparatus (DUV light or VUV light) or the like, a transmissive reticle is generally used, and the reticle substrate is quartz glass, fluorine-doped quartz glass, fluorite, or Crystal or the like is used. In addition, a reflective mask is used in an EUV exposure apparatus, and a transmission mask (stencil mask, membrane mask) is used in a proximity type X-ray exposure apparatus or a mask projection type electron beam exposure apparatus. A silicon wafer or the like is used as the substrate.

 [0216] 《Device manufacturing method》

 Next, an embodiment of a device manufacturing method using the exposure apparatus and the exposure method of each embodiment described above in a lithographic process will be described.

 FIG. 11 shows a flowchart of an example of manufacturing devices (semiconductor chips such as ICs and LSIs, liquid crystal panels, CCDs, thin-film magnetic heads, micromachines, etc.). As shown in FIG. 11, first, in step 201 (design step), a function / performance design of a device (for example, a circuit design of a semiconductor device) is performed, and a pattern design for realizing the function is performed. . Subsequently, in step 202 (mask manufacturing step), a mask on which the designed circuit pattern is formed is manufactured. On the other hand, in step 203 (wafer manufacturing step), a wafer is manufactured using a material such as silicon.

 [0218] Next, in step 204 (wafer processing step), using the mask and the wafer prepared in step 201-step 203, an actual circuit or the like is placed on the wafer by lithography technology or the like as described later. Form. Next, in step 205 (device assembly step), device assembly is performed using the wafer processed in step 204. Step 205 includes steps such as a dicing step, a bonding step, and a packaging step (chip sealing) as necessary.

[0219] Finally, in step 206 (inspection step), inspections such as an operation confirmation test and an endurance test of the device created in step 205 are performed. After these steps, the device is complete And this is shipped.

 [0220] Fig. 12 shows a detailed flow example of step 204 in the semiconductor device. In FIG. 12, in step 211 (oxidation step), the surface of the wafer is oxidized. In step 212 (CVD step), an insulating film is formed on the wafer surface. In step 213 (electrode formation step), an electrode is formed on the wafer by vapor deposition. In step 214 (ion implantation step), ions are implanted into the ueno. Each of the above steps 211 to 214 constitutes a pre-processing step of each stage of the wafer processing, and is selected and executed according to a necessary process in each stage.

 [0221] In each stage of the wafer process, when the above-described pre-processing step is completed, a post-processing step is executed as follows. In this post-processing step, first, in step 215 (resist forming step), a photosensitizing agent is applied to the wafer. Subsequently, in step 216 (exposure step), the circuit pattern of the mask is transferred to the wafer by the exposure apparatus and the exposure method described above. Next, in Step 217 (development step), the exposed wafer is developed, and in Step 218 (etching step), the exposed members other than the portion where the resist remains are removed by etching. Then, in step 219 (resist removing step), unnecessary resist after etching is removed.

 [0222] By repeatedly performing these pre-processing steps and post-processing steps, multiple circuit patterns are formed on the wafer.

 According to the device manufacturing method of the present embodiment described above, the exposure apparatus and the exposure method of the above embodiment are used in the exposure step (step 216), so that the synchronization error between the reticle and the pheno can be reduced as much as possible. In this state, scanning exposure is performed, whereby the pattern of the reticle can be transferred onto each shot area on the wafer W with high accuracy. In addition, since the movement between shot areas is performed without stopping the wafer stage between shot areas on the same row on the wafer, the reticle pattern can be transferred to each shot area on the wafer W with high throughput. Becomes possible. Therefore, according to the device manufacturing method of the present embodiment, it is possible to improve the productivity (including the yield) of a highly integrated device.

Industrial applicability The exposure method and exposure apparatus of the present invention are suitable for transferring a mask pattern onto a photosensitive object. Further, the device manufacturing method of the present invention is suitable for manufacturing electronic devices such as semiconductor elements and liquid crystal display elements.

Claims

The scope of the claims

 [1] An exposure method for synchronously moving a mask stage holding a mask and an object stage holding a photosensitive object in a predetermined scanning direction, and transferring a pattern formed on the mask onto the photosensitive object. ,

 The object stage is moved synchronously with the mask stage and the object stage in consideration of a first correction value group for ascending a position deviation, which is a difference between a target position of the object stage and its current position, to zero. A first step of repeatedly obtaining a second group of correction values for ascending a position deviation, which is a difference between a target position of the mask stage corresponding to the current position and the current position, to zero by learning control;

 The mask stage and the object stage are synchronously moved in the scanning direction while correcting the positions of the object stage and the mask stage using the first correction value group and the second correction value group, respectively. A second step of transferring a pattern formed on the mask onto the photosensitive member.

[2] The exposure method according to claim 1, wherein

 An exposure method further comprising, before the first step, a third step of repeatedly obtaining the first correction value group by learning control while moving the object stage in the same manner as in the first step.

[3] In the exposure method according to claim 1,

 The exposure method, wherein in the first step, iterative learning control for obtaining the first correction value group is performed in parallel during the synchronous movement.

[4] An exposure method for moving an object stage holding a photosensitive object in a predetermined scanning direction and exposing a plurality of divided areas on the photosensitive object to form a predetermined pattern in each divided area,

Prior to the actual exposure operation, the scanning direction and the non-scanning direction orthogonal to the scanning direction are the same as during the movement operation between the divided areas performed between the exposure for one partitioned area and the exposure for the next partitioned area. A first method of moving the object stage along a predetermined path that intersects both in the scanning direction and asymptotically reducing a positional deviation, which is a difference between a target position of the object stage in the non-scanning direction and its current position, to zero. A first step of obtaining a group of correction values by iterative learning control; A movement operation between the divided areas is performed while correcting the position of the object stage in the non-scanning direction in consideration of the first correction value group, and the object stage is moved before and after the movement operation between the divided areas. Moving in the scanning direction to perform the exposure, and forming the pattern in each of the divided areas on the photosensitive object.

[5] The exposure method according to claim 4, wherein

 In the first step, when the object stage is moved along a predetermined path, a second position deviation, which is a difference between a target position of the object stage in the scanning direction and its current position, is gradually approached to zero. An exposure method, wherein a position of the object stage in the scanning direction is corrected in consideration of a correction value group.

[6] The exposure method according to claim 5, wherein

 Prior to the first step, the third correction value group is repeatedly obtained by learning control while moving the object stage in the scanning direction in the same manner as in the movement in the scanning direction during exposure. An exposure method further comprising a step.

[7] An exposure method for moving an object stage holding a photosensitive object in a predetermined scanning direction and exposing a plurality of divided areas on the photosensitive object to form a predetermined pattern in each divided area,

 A position deviation, which is a difference between a target position and a current position of the object stage, asymptotically approaching zero, based on a correction value group corresponding to an operation condition selected from a plurality of correction value groups, the position of the object stage. An exposure method including an exposure step of controlling the object stage in accordance with the operating condition while correcting the above.

[8] The exposure method according to claim 7,

 The plurality of correction value groups include an operation pattern of the object stage when continuously exposing a plurality of partitioned areas on the same row, and an operation pattern of the object stage when continuously exposing a plurality of partitioned areas on different rows. An exposure method characterized by including a correction value group individually corresponding to an operation pattern.

[9] The exposure method according to claim 7,

The exposure method according to claim 1, wherein the plurality of correction value groups include correction value groups individually corresponding to a plurality of operation sequences of the object stage.

[10] The exposure method according to claim 7, wherein

 The plurality of correction value groups include correction value groups individually corresponding to a scanning operation and a step operation of the object stage in the scanning direction and a step operation of a non-scanning direction orthogonal to the scanning direction. Characteristic exposure method.

 [11] The exposure method according to claim 7,

 An exposure method, wherein each of the correction value groups is obtained by repetitive learning control performed in advance for each operating condition.

 [12] In the exposure method according to claim 7, the predetermined pattern is formed on a mask, and at the time of exposure, a mask stage holding the mask and the object stage move in a predetermined scanning direction. By the synchronous movement, the predetermined pattern is transferred to each of the plurality of partitioned areas on the photosensitive object, and in the exposure step, a positional deviation, which is a difference between a target position and a current position of the mask stage, is asymptotically reduced to zero. An exposure method, wherein the position of the mask stage is corrected based on a group of correction values to be performed.

 [13] The exposure method according to claim 12, wherein

 The exposure method according to claim 1, wherein the correction value group for correcting the position of the mask stage is obtained by a repetitive learning control performed in advance.

 [14] The exposure method according to claim 13,

 In the exposure step, a movement sequence of the two stages in which the two stages stop and stop in the scanning direction between the exposure of one partitioned region and the exposure of the next partitioned region is set as the operating condition, An exposure method, wherein the acceleration of the two stages is started after a lapse of a predetermined time from the end of the exposure of the one partitioned area.

 [15] An exposure apparatus for synchronously moving a mask and a photosensitive object in a predetermined scanning direction and transferring a pattern formed on the mask onto the photosensitive object,

 A mask stage on which the mask can be placed and which can be moved at least in the scanning direction;

 An object stage on which the photosensitive object can be placed and at least movable in the scanning direction;

The object stage is controlled according to a position deviation which is a difference between the target position and the current position. An object stage control system including: a first control system that performs a first learning process; and a first learning controller that repeatedly obtains a first correction value group that causes the position deviation to approach zero.

 A second control system for controlling the mask stage according to a position deviation which is a difference between the target position and the current position, and a second correction value group for ascending the position deviation to zero are repeatedly acquired by learning. A mask stage control system including a second learning controller, wherein a command value corresponding to a current position of the object stage is given as the target position during the synchronous movement;

 According to the setting conditions, the first and second learning controllers are set to a connected state or a non-connected state with respect to the corresponding control system, and the specific learning set to be connected to the corresponding control system is set. The correction value group acquired by the controller is sequentially stored, and the corresponding correction value group acquired in advance by the corresponding learning controller is stored in the control system in which the corresponding learning controller is disconnected. A control device for sequentially inputting the position deviation as a correction value.

[16] The exposure apparatus according to claim 15,

 As the setting condition, a first condition for connecting the first learning controller to the object stage control system and a second condition for connecting the second learning controller to the mask stage control system can be set. An exposure apparatus, comprising:

[17] The exposure apparatus according to claim 15,

 As the setting conditions, a first condition for connecting the first and second learning controllers to the object stage control system and the mask stage control system, respectively, and the first and second learning controllers are connected to the object stage control system. An exposure apparatus, wherein a second condition for disconnecting the mask stage control system can be set.

[18] An exposure apparatus for moving a photosensitive object in a predetermined scanning direction and exposing a plurality of divided areas on the photosensitive object respectively to form a predetermined pattern in each divided area,

 An object stage on which the photosensitive object can be placed and which can be moved in a two-dimensional direction including the scanning direction and a non-scanning direction orthogonal to the scanning direction;

An operating condition selected from a plurality of correction value groups for controlling the object stage and for ascending a position deviation, which is a difference between a target position and a current position of the object stage, to zero. And a stage control system that corrects the position of the object stage based on a correction value group corresponding to the case.

 [19] The exposure apparatus according to claim 18, wherein

 The plurality of correction value groups include an operation pattern of the object stage when continuously exposing a plurality of partitioned areas on the same row, and an operation pattern of the object stage when continuously exposing a plurality of partitioned areas on different rows. An exposure apparatus characterized by including a correction value group individually corresponding to an operation pattern.

[20] The exposure apparatus according to claim 18, wherein

 An exposure apparatus, wherein the correction value group includes a correction value group individually corresponding to a plurality of operation sequences of the object stage.

[21] The exposure apparatus according to claim 18, wherein

 An exposure apparatus wherein each of the correction value groups includes a correction value group individually corresponding to each of a scanning operation and a step operation of the object stage in the scanning direction and a step operation of the object stage in the non-scanning direction. .

[22] The exposure apparatus according to claim 18, wherein

 An exposure apparatus, wherein each of the correction value groups is obtained by repetitive learning control performed in advance for each operation condition.

[23] The exposure apparatus according to claim 22, wherein

 A mask stage on which the mask on which the predetermined pattern is formed can be mounted, and further includes a mask stage movable at least in the scanning direction;

 The stage control system executes a movement sequence of the two stages in which the object stage and the mask stage stop and stop in the scanning direction between the exposure of one partitioned area and the exposure of the next partitioned area. In this case, the exposure apparatus starts accelerating the two stages after a lapse of a predetermined time from the end of the exposure of the one divided area.

[24] The exposure apparatus according to claim 23,

The stage control system is configured to determine the position of the mask stage at the time of synchronous movement with the object stage, based on a correction value group for ascending a position deviation, which is a difference between a target position and a current position of the mask stage, to zero. An exposure apparatus for performing further correction.

[25] The exposure apparatus according to claim 24,

 The exposure apparatus according to claim 1, wherein the correction value group for correcting the position of the mask stage is obtained by a repetitive learning control performed in advance.

[26] The exposure apparatus according to claim 25,

 The stage control system is configured to execute the movement sequence of the two stages, in which the two stages stop and stop in the scanning direction between the exposure of one partitioned region and the exposure of the next partitioned region. An exposure apparatus characterized in that acceleration of both stages is started after a lapse of a predetermined time from the end of exposure of one partitioned area.

[27] An exposure apparatus for synchronously moving a mask and a photosensitive object in a predetermined scanning direction, and transferring a pattern formed on the mask to a plurality of partitioned areas on the photosensitive object, respectively. A mask stage that is mountable and movable at least in the scanning direction;

 An object stage on which the photosensitive object can be placed, and which can be moved in a two-dimensional direction of the scanning direction and a non-scanning direction orthogonal to the scanning direction;

 While controlling the two stages, when executing the movement sequence of the two stages, in which the two stages stop and stop in the scanning direction between the exposure of one partitioned region and the exposure of the next partitioned region, A stage control system that starts acceleration of the two stages after a lapse of a predetermined time from the end of exposure of one partitioned area.

[28] A device manufacturing method including a lithographic process,

 15. A device manufacturing method, wherein a pattern is transferred onto a photosensitive object by the exposure method according to claim 114 in the lithographic process.