WO2003079418A1

WO2003079418A1 - Aligner and device manufacuring method

Info

Publication number: WO2003079418A1
Application number: PCT/JP2003/003003
Authority: WO
Inventors: Junichi Kosugi; Tetsuo Taniguchi; Naoyuki Kobayashi; Yoshitomo Nagahashi
Original assignee: Nikon Corporation
Priority date: 2002-03-15
Filing date: 2003-03-13
Publication date: 2003-09-25
Also published as: TW200305925A; AU2003220867A1; JPWO2003079418A1; KR20040102033A; TWI300953B

Abstract

The suppression of a fluctuation of a base line by a temperature control necessary for each constituent apparatus. An aligner has a first control system for setting the temperature of a first liquid, and for circulating the first liquid with a set temperature through at least one object of a projection optical system and a board stage to control the temperature of the object, and a second control for setting the temperature of a second liquid independently of setting by the first control system, and for circulating the second liquid with a set temperature through a reticle stage to control the temperature of the reticle stage. The first and second control systems have different set capabilities in the point of the size of a temperature range in setting a liquid temperature.

Description

TECHNICAL FIELD The present invention relates to an exposure apparatus for projecting and exposing a pattern image of a mask onto a substrate such as a wafer in a device manufacturing process of a semiconductor element or a liquid crystal display element, and transferring a device pattern to the substrate. The present invention relates to a device manufacturing method.

This application is based on Japanese Patent Application Nos. 2000-72026 and 2000-22885, the contents of which are incorporated herein. BACKGROUND ART When manufacturing a semiconductor device or a liquid crystal display device by a photolithographic process, a pattern image of a photomask or a reticle (hereinafter collectively referred to as a “reticle”) is projected onto a photosensitive substrate via a projection optical system. A projection exposure apparatus that projects onto a shot area is used. In recent years, this type of projection exposure apparatus includes a photosensitive substrate mounted on a two-dimensionally movable stage, and the stage is used to move the photosensitive substrate in a stepwise manner so that a reticle pattern image is transferred onto a photosensitive substrate such as a wafer. A so-called step 'and' rebeat type exposure apparatus, for example, a reduction projection type exposure apparatus (stepper), which repeats an operation of sequentially exposing each shot area to a shot area, is often used. In recent years, a so-called step-and-scan type exposure apparatus has been used, in which a reticle and a wafer are synchronously moved during wafer exposure, thereby sequentially exposing each shot area on the wafer. ing.

For example, microdevices such as semiconductor devices are formed by laminating a large number of circuit patterns on a wafer coated with a photosensitive material as a photosensitive substrate, so that the second and subsequent circuit patterns are projected and exposed on the wafer. In this case, the position of each shot area on the wafer where a circuit pattern has already been formed and the pattern image of the reticle to be exposed from now on It is necessary to precisely perform alignment, that is, alignment between the wafer and the reticle. For example, Patent Document 1 discloses a method of aligning wafers when performing overlay exposure on a single wafer in which a shot area where a circuit pattern is exposed is arranged in a matrix. The so-called Enhanced-Global Arrangement (EGA) has become mainstream.

The EGA method specifies at least three areas (hereinafter referred to as EGA shots) among a plurality of shot areas formed on a wafer (object) and attaches them to each shot area. The coordinate position of the alignment mark (mark) is measured by the alignment sensor. After that, error parameters (offset, scale, rotation, orthogonality) related to array characteristics (positional information) of the shot area on the wafer are statistically calculated based on the measured values and the design values by the least square method or the like. To decide. Then, based on the determined parameter values, the design coordinate values of all shot areas on the wafer are corrected, and the wafer stage is stepped according to the corrected coordinate values to position the wafer. It is a method to do. As a result, the projected image of the reticle pattern and each of the plurality of shot areas on the wafer are processed points set in the shot area (the reference points at which coordinate values are measured or calculated. (The center of the dot area), and the exposure is performed with the overlap.

Conventionally, as an alignment sensor for measuring an alignment mark on a wafer, a method using an off-axis type alignment system arranged near a projection optical system is known. In this method, after measuring an alignment mark using an alignment system of an off-axis system, the wafer stage is moved by a fixed amount related to a base line amount, which is a distance between the projection optical system and the off-axis alignment system. By simply feeding the wafer, the reticle pattern can be immediately superimposed on the shot area on the wafer and exposed. As described above, since the baseline amount is a very important manipulated variable in a photolithographic process, strictly accurate measurement values are required.

However, the above-mentioned baseline amount may fluctuate during exposure (baseline drift) due to thermal expansion or thermal deformation of an alignment system or the like due to heat generated by various processes. In this case, an error occurs in the positioning of the wafer, and the overlay accuracy In the past, a baseline check was performed each time a predetermined number of wafers were exposed to prevent the overlay accuracy from deteriorating (Japanese Patent Laid-Open No. No. 61-444492).

However, the conventional exposure apparatus and device manufacturing method as described above have the following problems.

In recent years, with the further miniaturization of patterns, the exposure apparatus of the step-and-repeat type to the step-and-scan type (hereinafter referred to as “scan type”) is becoming mainstream. In the scanning method, since both the wafer and the reticle scan during exposure (during pattern transfer), not only the wafer stage but also the reticle stage tends to have heat under the influence of the motor, etc. Gradually deforms.

The position of the stage is measured using an interference system, but if the distance between the moving mirror and the reticle changes due to the deformation of the stage, the baseline will fluctuate, and the overlay accuracy will deteriorate. In addition, the temperature of the atmosphere around the stage rises due to the heat generated by the stage, and the stage positioning accuracy deteriorates due to the fluctuation of the optical path of the interferometer.

Therefore, conventionally, cooling is performed by sending (circulating) the refrigerant to the heat generating part while controlling the refrigerant temperature with a temperature controller. However, the wafer stage ゃ reticle stage, which generates heat intensely in 1/10 ° C units, and the projection optical system alignment system, whose temperature must be controlled in 1Z100 ° C units, can be controlled by a single temperature controller. When cooling, if the coolant temperature is controlled based on the temperature of the projection optical system, the cooling capacity of the wafer stage / reticle stage, which changes greatly, will not be sufficient, and conversely, the temperature of the wafer stage / reticle stage will decrease. If the refrigerant temperature is controlled on the basis of the standard, the precise (fine) temperature control required for the projection optical system alignment system cannot be performed. In particular, since the reticle stage moves at a distance and speed corresponding to the projection magnification with respect to the wafer stage, the amount of heat generated is extremely large, and it is difficult to control the temperature with the same control system as the projection optical system alignment system. Have difficulty. As described above, if the temperature control is not sufficiently performed, a problem occurs in that the baseline variation becomes large and the overlay accuracy is deteriorated. Disclosure of the invention

The present invention has been made in consideration of the above points, and has as its object to provide an exposure apparatus and a device manufacturing method capable of controlling the temperature required for each component and suppressing baseline fluctuation. I do.

In order to achieve the above object, the present invention employs the following configuration corresponding to FIGS. 1 to 10 showing the embodiment.

An exposure apparatus according to the present invention is an exposure apparatus that projects a pattern image of a reticle held on a reticle stage onto a substrate held on a substrate stage via a projection optical system. The first control system controls the temperature of the first liquid by circulating the first liquid whose temperature has been set to at least one of the projection optical system and the substrate stage, and controls the temperature of the second liquid. A second control system that controls the temperature of the reticle stage by circulating the set second liquid to the reticle stage and setting the temperature independently of the first control system. The first and second control systems are characterized in that they have different setting capabilities in terms of the size of the temperature range described above.

Therefore, in the exposure apparatus of the present invention, the projection optical system and the substrate stage are controlled, for example, in units of 1Z100 ° C. by circulating the first liquid in the first control system, and the second control system controls the second optical system. By circulating the liquid, the reticle stage can be independently controlled, for example, in units of 10 to 10 ° C. In other words, by setting the first and second control systems individually according to the temperature range required for the projection optical system and the reticle stage, it becomes possible to control the temperature with the accuracy required for each device. Baseline fluctuations caused by temperature fluctuations can be suppressed. The exposure apparatus of the present invention is an exposure apparatus that projects a pattern image of a reticle held on a reticle stage onto a substrate held on a substrate stage via a projection optical system. Setting the first circulating condition for circulating the first liquid to at least one of the projection optical system and the substrate stage, A first control system for controlling the temperature of the object by circulating the first liquid under the condition;

The second circulating condition for circulating the second liquid to the stage is set independently of the first circulating condition, and the second liquid is circulated under the second circulating condition. A second control system for controlling a temperature of the stage, a first detecting means for detecting a temperature of the first liquid before circulating the object, and a temperature of the first liquid after circulating the object, respectively, a reticle stage And a second detection unit for detecting a temperature of the second liquid before circulating through the reticle stage and a temperature of the second liquid after circulating through the reticle stage, respectively. The first control system sets the first circulation condition based on the detection result, and the second control system sets the second circulation condition based on the detection result of the second detection means.

Therefore, in the exposure apparatus of the present invention, the projection optical system and the substrate stage are controlled, for example, in units of 1/1000 ° C. by circulating the first liquid under the first circulation condition, and the second control system performs By circulating the two liquids, the reticle stage can be independently controlled, for example, in units of 110 ° C. In other words, by setting the first and second control systems individually according to the temperature range required for the projection optical system and the reticle stage, it becomes possible to control the temperature with the accuracy required for each device, The resulting baseline fluctuation can be suppressed. At this time, the first and second circulating conditions are set based on the temperatures of the first and second liquids detected before and after circulating in each device. In addition, highly accurate temperature control can be performed based on the temperature change of the second liquid.

An exposure apparatus according to the present invention is an exposure apparatus that projects a pattern image of a reticle held on a reticle stage onto a substrate held on a substrate stage via a projection optical system.ぴ The substrate stage has a plurality of drive sources, and among the plurality of drive sources and the projection optical system, the first control that performs temperature control for the first control object with the heat generation or temperature change within the first fixed amount System, and a plurality of drive sources and a projection optical system, in which a heat generation amount or a temperature change amount larger than a first predetermined amount is set as a second control target, and a second control for performing temperature control independently of the first control system. It is characterized by having a system and Therefore, in the exposure apparatus according to the present invention, the first control system controls the drive source and the projection optical system of the substrate stage having a small heat value or a small temperature change amount as the first control object, and the heat value or the temperature change amount is relatively small. The large reticle stage drive source can be controlled independently by the second control system with the second control target. In other words, by making the control target according to the heat generation amount or the temperature change amount of the drive source of the projection optical system stage, the temperature control can be performed with the accuracy required for each device, and the baseline caused by the temperature fluctuation can be obtained. Fluctuations can be suppressed.

Further, the device manufacturing method of the present invention includes a step of transferring a pattern formed on a reticle onto a substrate using the exposure apparatus according to any one of claims 1 to 26. Is what you do.

Therefore, in the device manufacturing method of the present invention, it is possible to transfer a pattern onto a substrate in a state where necessary temperature control has been performed, and to suppress a baseline variation caused by a temperature variation, thereby achieving an excellent overlay accuracy. Device can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram of an exposure apparatus of the present invention.

FIG. 2 is an external perspective view of a reticle stage included in the exposure apparatus.

FIG. 3 is an external perspective view of a wafer stage constituting the exposure apparatus.

FIG. 4 is a diagram showing a temperature control system relating to the entire exposure apparatus in the first embodiment. FIG. 5 is a diagram showing a temperature control system related to the reticle stage.

FIG. 6 is a diagram showing a temperature control system related to the wafer stage.

FIG. 7 is a flowchart illustrating an example of a semiconductor device manufacturing process.

FIG. 8 is a diagram schematically showing a temperature control system relating to the entire exposure apparatus in the second embodiment.

FIG. 9 is a diagram schematically showing a temperature control system relating to the entire exposure apparatus in the third embodiment.

FIG. 10 shows a simplified temperature control system for the reticle stage in the fourth embodiment. FIG. 11A to 11C are diagrams showing a modification of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a first embodiment of an exposure apparatus and a device manufacturing method according to the present invention will be described with reference to FIGS. Here, for example, as an exposure apparatus, a scanning ス stepper that transfers a circuit pattern of a semiconductor device formed on a reticle onto a wafer while synchronously moving the reticle and the wafer during exposure (during pattern transfer). This will be explained using an example of the case of using.

The exposure apparatus 1 shown in FIG. 1 includes an illumination optical system IU that illuminates a rectangular (or arc) illumination area on a reticle (mask) R with uniform illumination by exposure illumination light from a light source (not shown). A stage apparatus 4 including a reticle stage (mask stage) 2 for holding and moving the reticle R and a reticle surface plate 3 for supporting the reticle stage 2; and a wafer (substrate) for illuminating light emitted from the reticle R. A projection optical system PL for projecting onto the W, a wafer stage (substrate stage) 5 for holding and moving a wafer W as a sample, and a stage device 7 including a wafer surface plate 6 for holding the wafer stage 5; It roughly comprises a stage device 4 and a reaction frame 8 having a projection optical system PL. Here, the direction of the optical axis of the projection optical system PL is defined as the Z direction, the direction of the synchronous movement of the reticle R and the wafer W in the direction orthogonal to the Z direction is defined as the Y direction, and the direction of the asynchronous movement is defined as the X direction. Also, the rotation directions around each axis are Θ Ζ, Θ, Θ Χ.

The illumination optical system I U is supported by a support column 9 fixed to the upper surface of the reaction frame 8. The illumination light for exposure includes, for example, ultraviolet bright lines (g-line, i-line) and KrF excimer laser light (wavelength) emitted from an ultra-high pressure mercury lamp.

Deep ultraviolet light (DUV light) such as 248 nm, and ArF excimer laser light (wavelength 19

3 nm) and F ₂ laser beam (wavelength: 1 5 7 nm) vacuum ultraviolet light such as (VUV) and the like. The reaction frame 8 is installed on a base plate 10 horizontally placed on the floor, and has upper and lower sides formed with stepped portions 8a and 8b protruding inward, respectively. ing.

In the stage device 4, the reticle surface plate 3 is supported almost horizontally on the step portion 8a of the reaction frame 8 at each corner via the vibration isolating unit 11 (note that the reticle surface plate 3 is located on the back side of the drawing). An aperture 3a through which a pattern image formed on reticle R passes is formed in the center of the scut (not shown). Note that metal or ceramics can be used as the material of the reticle surface plate 3. The anti-vibration unit 11 has a configuration in which an air mount 12 whose internal pressure is adjustable and a voice coil motor 13 are arranged in series on the step 8a. With these vibration isolation units 11, micro vibrations transmitted to the reticle surface plate 3 via the base plate 10 and the reaction frame 8 are isolated at the micro G level (G is the gravitational acceleration ).

A reticle stage 2 is supported on the reticle base 3 so as to be two-dimensionally movable along the reticle base 3. A plurality of air bearings (air pads) 14 are fixed to the bottom surface of the reticle stage 2, and the reticle stage 2 floats on the reticle surface plate 3 with a clearance of about several microns by the air bearings 14. Supported. At the center of the reticle stage 2, there is formed an opening 2a which communicates with the opening 3a of the reticle surface plate 3 and through which the pattern image of the reticle R passes.

The reticle stage 2 will be described in detail. As shown in FIG. 2, the reticle stage 2 is fixed on the reticle surface plate 3 in the Y-axis direction by a pair of Y linear motors (drive sources) 15 and 15. A reticle coarse movement stage 16 driven by a stroke, and a pair of X voice coil motors (drive sources) 17 X and a pair of Y voice coil motors (drive sources) are moved on the reticle coarse movement stages 16. A reticle fine movement stage 18 that is finely driven in the X, Υ, and Ζ directions by 17 Y is provided (note that these are shown as one stage in FIG. 1). .

Each peliner motor 15 has a plurality of non-contact bearings on the reticle surface plate 3. An air bearing (air pad) 19 is supported by the stator 20 which is levitated and supported in the Y-axis direction, and is provided corresponding to the stator 20 and is fixed to the reticle coarse movement stage 16 via the connecting member 22. Mover 2 1. Therefore, the stator 20 moves in the one Y direction as a counter mass according to the movement of the reticle coarse movement stage 16 in the + Y direction according to the law of conservation of the movement amount. The movement of the stator 20 cancels the reaction force caused by the movement of the reticle coarse movement stage 16 and also prevents the center of gravity from changing. In addition, since the moving element 21 and the stator 20 in the Y linear motor 15 are coupled, when they relatively move, a force acts to stop at the original position. For this reason, in the present embodiment, a trim motor 72 (drive source; not shown in FIG. 2; see FIG. 5) for correcting the movement fi so that the stator 20 reaches a predetermined position is provided. I have.

The reticle coarse movement stage 16 is fixed to the upper surface of the upper protruding portion 3b formed in the center of the reticle surface plate 3 and guided in the Y-axis direction by a pair of Y guides 51, 51 extending in the Y-axis direction. It is supposed to be. Further, reticle coarse movement stage 16 is supported in a non-contact manner by an air bearing (not shown) with respect to Y guides 51 and 51.

The reticle fine movement stage 18 is configured to hold the reticle R by suction via a vacuum chuck (not shown). A pair of Y-moving mirrors 52 a and 52 b made of a corner cube are fixed to one end of the reticle fine movement stage 18 in the Y direction, and to a + X end of the reticle fine movement stage 18. The X movable mirror 53 composed of a plane mirror extending in the Y-axis direction is fixed. Then, three laser interferometers (all not shown) that irradiate the measuring beams to these movable mirrors 52 a, 52 b, and 53 measure the distance between each movable mirror and the reticle. The position of the stage 2 in the X, Y, and Θ (rotation around the Ζ axis) direction is measured with high accuracy.

Returning to Fig. 1, 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 field, and quartz or fluorite is used as the optical glass material. A 1/4 (or 1/5) diopter optical system composed of a refractive optical element (lens element) is used. For this reason, reticle R is irradiated with illumination light. Then, of the circuit pattern on the reticle R, the imaging light flux from the part illuminated with the illumination light enters the projection optical system PL, and a partially inverted image of the circuit pattern is projected onto the image plane of the projection optical system PL. At the center of the circular field of view on the side, an image is formed with a slit-like shape limited. As a result, the projected partial inverted image of the circuit pattern is formed on the resist layer on the surface of one of the shot areas of the plurality of shot areas on the wafer W arranged on the imaging plane of the projection optical system PL. It is reduced and transferred. A flange 23 integrated with the lens barrel is provided on the outer periphery of the lens barrel of the projection optical system PL. The projection optical system PL is mounted on a barrel base 25 composed of an object or the like that is supported substantially horizontally on a step 8 b of the reaction frame 8 via an anti-vibration unit 24. Is inserted from above with the Z direction, and the flanges 23 are engaged.

The anti-vibration unit 24 is disposed at each corner of the lens barrel base 25 (the anti-vibration unit at the back of the drawing is not shown), and an air mount 26 and a voice that can adjust the internal pressure are provided. The coil motor 27 is arranged in series on the step 8b. Micro vibration transmitted to the lens barrel base 25 (and, consequently, the projection optical system PL) via the base plate 10 and the reaction frame 8 by the vibration isolating unit 24 at the microphone port G level. It is becoming more and more rude.

The stage device 7 includes a wafer stage 5, a wafer surface plate 6 that supports the wafer stage 5 so as to be movable in a two-dimensional direction along the XY plane, and a sample stage that is provided integrally with the wafer stage 5 and that holds the wafer W by suction. It mainly comprises an X guide bar XG that supports the ST, the wafer stage 5 and the sample stage ST so as to be relatively movable. A plurality of air bearings (air pads) 28, which are non-contact bearings, are fixed to the bottom surface of the wafer stage 5, and these air bearings 28 move the wafer stage 5 onto the wafer surface plate 6, for example, a It is levitated and supported through the clearance of the mouth.

The wafer surface plate 6 is supported almost horizontally above the base plate 10 via a vibration isolation unit 29. The anti-vibration units 29 are arranged at each corner of the wafer platen 6 (the anti-vibration units on the back side of the drawing are not shown), and the air mount 30 and the voice coil motor whose internal pressure can be adjusted. 3 and 1 are parallel on base plate 10 It is configured to be arranged in. By these vibration isolating units 29, micro vibrations transmitted to the wafer surface plate 6 via the base plate 10 are insulated at a micro G level.

As shown in Fig. 3, the X guide bar XG has a long shape along the X direction, and movers 36 and 36 composed of armature units are provided at both ends in the length direction. ing. The stators 37, 37 having magnet units corresponding to the movers 36, 36 are provided on support portions 32, 32 projecting from the base plate 10 (see FIG. 1). (See FIG. 1 for simplified illustration of the mover 36 and the stator 37.) A moving coil type rear motor (drive source) 33, 33 is constituted by the mover 36 and the stator 37, and the mover 36 is connected to the stator 37 by electromagnetic force. The X guide bar XG moves in the Y direction by being driven by the interaction, and rotates in the Θ direction by adjusting the drive of the linear motors 33, 33. That is, the wafer stage 5 (and the sample stage ST, hereinafter simply referred to as the sample stage ST) is driven in the Y direction and the Ζ direction by the linear motor 33 almost integrally with the X guide bar XG. I have.

The mover of the X trim motor 34 is attached to one X direction side of the X guide bar XG. The X trim motor 34 adjusts the position of the X guide bar XG in the X direction by generating a thrust in the X direction. The stator (not shown) is provided on the reaction frame 8. . Therefore, a reaction force when driving the wafer stage 5 in the X direction is transmitted to the base plate 10 via the reaction frame 8.

The sample stage ST maintains a predetermined gap in the Z-direction between the X-guide bar XG and the X-guide bar XG via a magnetic guide composed of a magnet and an actuator so as to be relatively movable in the X-direction. Supported and held in contact. Further, the wafer stage 5 is driven in the X direction by electromagnetic interaction with an X linear motor (drive source) 35 having a stator embedded in an X guide bar XG. The mover of the X linear motor is not shown, but is attached to the wafer stage 5. Wafer W is fixed on the upper surface of sample stage ST via wafer holder 41 by vacuum suction or the like. (See Fig. 1, not shown in Fig. 3.)

The position of the wafer stage 5 in the X direction is measured by measuring the position change of the moving mirror 43 fixed to a part of the wafer stage 5 with reference to the reference mirror 42 fixed to the lower end of the barrel of the projection optical system PL. The laser interferometer 44 measures in real time with a predetermined resolution, for example, a resolution of about 0.5 to 1 nm. Note that the position of the wafer stage 5 in the Y direction is measured by a reference mirror, a laser interferometer, and a movable mirror (not shown) which are arranged substantially orthogonal to the reference mirror 42, the movable mirror 43, and the laser interferometer 44. Is done. At least one of these laser interferometers is a multi-axis interferometer having two or more measuring axes. Based on the measured values of these laser interferometers, the wafer stage 5 (and thus the wafer W) is used. In addition to the XY position, Θ the amount of rotation or, in addition to these, the amount of leveling can be obtained.

Furthermore, three laser interferometers 45 are fixed to the flange 23 of the projection optical system PL at three different places (however, in FIG. 1, one of these laser interferometers is representative). ). Openings 25a are respectively formed in portions of the lens barrel base 25 facing each of the laser interferometers 45, and the laser interferometers 45 from the laser interferometer 45 in the Z direction are formed through these openings 25a. A laser beam (measuring beam) is applied to the wafer surface plate 6. A reflection surface is formed on the upper surface of the wafer surface plate 6 at a position facing each measurement beam. For this reason, three different Z positions of the wafer surface plate 6 are measured by the three laser interferometers 45 with reference to the flange 23. .

Next, a temperature control system in the exposure apparatus 1 will be described with reference to FIGS. FIG. 4 shows a temperature control system for the entire exposure apparatus, FIG. 5 shows a temperature control system for the reticle stage 2, and FIG. 6 shows a temperature control system for the wafer stage 5. As a medium (refrigerant) for temperature control, it is possible to use HFE (Hydro-Furushiro-'ether)） florinate, but in this embodiment, it has a low global warming potential and ozone depletion. Since the coefficient is zero, HFE is used from the viewpoint of global environmental protection.

This temperature control system uses a projection optical system PL and an The first control system 61 controls and controls the temperature of the reticle stage AL and the wafer stage 5 using the refrigerant as the second liquid. It is broadly divided into a second control system 62 that controls and manages temperature independently of the system 61. In this temperature control system, the projection optical system PL and the alignment system AL whose heat generation amount (temperature change amount) is within a predetermined amount (first predetermined amount) are subjected to the first temperature control, and the heat generation amount is the predetermined amount. The larger reticle stage 2 and wafer stage 5 are subject to the second temperature control.

The refrigerant in the tank 63 whose temperature has been adjusted in the first control system 61 passes through a pump 64, a circulation system C1 that sequentially circulates through an alignment system AL and a projection optical system PL, and an evaporator 65. It is branched into a cooling system C2 to be cooled. The temperature of the refrigerant immediately after being discharged from the pump 64 is detected by the sensor 66 and output to the controller 67. Regarding the circulating system C1, the projection optical system PL has a wide temperature control range by the refrigerant by being helically piped around the lens barrel 68. In the present embodiment, in FIG. 4, the refrigerant is configured to circulate from the top to the bottom through a spirally arranged pipe around the lens barrel 68, but the present invention is not limited to this, and the coolant is circulated from the bottom to the top. The refrigerant may be helically circulated. Further, in the circulation system C1, a sensor 69 for detecting the refrigerant temperature before circulating in the projection optical system PL is provided, and the detection result is output to the controller 67. In the present embodiment, the temperature of the projection optical system PL is controlled by arranging a spiral pipe around almost the entire surface of the lens barrel 68 as described above, but the present invention is not limited to this. However, the present invention is not limited to this, and a so-called flange temperature control method may be adopted in which a pipe is arranged at a portion of the member (flange 23) holding the projection optical system PL to perform temperature control.

As an off-axis alignment AL, a laser beam such as He-Ne is applied to a dot array of alignment marks on wafer W, and the light diffracted or scattered by the mark is used. LSA (Laser Step Alignment) method to detect the mark position by using a light source such as a halogen lamp, etc. FIA (Field Image Alignment) method to measure mark position, on wafer W A diffraction grating alignment mark is irradiated with two coherent beams (semiconductor lasers, etc.) inclined in the pitch direction, causing the two generated diffracted lights to interfere with each other. The LIA (Laser Interferometric Alignment) method that measures the position of the mark can be used.However, the LSA method is used here, and the circulating system C1 uses the refrigerant in the alignment system AL for the alignment light source in the alignment system AL. Is circulated to control the temperature. As the circulation system, for example, similarly to the projection optical system PL, it is possible to spirally pipe a housing for housing the light source. In addition, in the alignment system AL, the temperature may be adjusted by circulating the refrigerant not only in the alignment light source but also in a housing that houses the alignment optical system. Similarly, in an alignment light source and a housing, not only in an off-axis system but also in a TTR (through the reticle) system or a TTL (through the lens) system that detects a mark on a wafer W via a projection optical system PL. On the other hand, the temperature can be adjusted by circulating the refrigerant.

The refrigerant that has circulated through the alignment system A L and the projection optical system PL in the circulation system C 1 is returned to the upper chamber of the tank 63 which is divided into two upper and lower sections.

On the other hand, the refrigerant in the cooling system C2 is branched into a path C3, which is cooled by the evaporator 65 and returns to the upper chamber of the tank 63, and a path C4 toward the heat exchanger 70. The evaporator 65 is cooled by a refrigerator 73 that circulates a gaseous refrigerant. The cooled refrigerant is used for heat exchange in the heat exchanger 70 in the route C4, and then returns to the upper chamber of the tank 63 and is cooled again.

A heater 71 controlled by a controller 67 is disposed in the lower chamber of the tank 63, and the controller 67 drives the heater 71 based on the detection results of the sensors 66, 69. By controlling the temperature of the alignment system AL and the projection optical system PL via the refrigerant, for example, 23 ° C. ± 0.01. Control (manage) to C. The first control system 61 circulates the refrigerant whose temperature has been adjusted by the heater 71 at the same flow rate for each temperature control target.

In the second control system 62, the refrigerant as the second liquid cooled in the heat exchanger 70 passes through the pump 74 and then circulates through the reticle stage 2 through the circulating system C5 and the wafer stage. It is branched to a circulation system C 6 which circulates through page 5. The coolant in the second control system 62 is configured to circulate in a closed system without returning to the tank 63.

In the circulation system C5, a heater Ί5 is provided downstream of the pump 74, and the refrigerant temperature before circulating through the reticle stage 2 and the refrigerant temperature after circulating through the reticle stage 2 are controlled. Sensors (second detection means) 76a and 76b for detecting the respective sensors are provided, and the detection results of the sensors 76a and 76b are output to the controller 77. The controller 77 simply averages the input detection results of the sensors 76 a 76 b and controls the driving of the heater 75 based on the obtained refrigerant temperature, thereby controlling the temperature of the reticle stage 2 to, for example, Control (manage) to 23 C ± 0.1 C.

In this embodiment, the refrigerant cooled by the heat exchanger 70 is configured to circulate through the pump 74. However, when the pressure loss of the heat exchanger 70 is large, the pump 74 is connected to the heat exchanger. Arranged upstream from 70 and the point where the return refrigerant (refrigerant after circulating through each stage 2, 5) to the circulation system C5 C6 joins is located upstream of the pump 74. May be configured.

Regarding the position of the temperature sensors 76a and 76b, the position of the temperature control target (reticle stage 2, more precisely, the motor for driving the reticle stage 2 described later) is determined as much as possible in any of the sensors. It is desirable to place it as close as possible. However, if it is not possible to get close to the temperature control target due to restrictions on the layout or the influence of the magnetic force of the motor, etc., some distance from the temperature control target within a range (location) that is not affected by external heat It is also possible to provide them at different positions.

In addition, the arrangement interval between each sensor and the temperature control target should be approximately the same as the arrangement interval between the sensors (the interval between sensor 76a and reticle stage 2, and the interval between sensor 77b and reticle stage). It is desirable that the intervals be approximately the same.) However, the arrangement of each sensor is not limited to this as long as it is within the range described above (within the range not affected by external heat).

Hereinafter, the temperature control system for reticle stage 2 will be described in more detail.

As shown in Figure 5, the circulatory system. 5 includes a circulating system C7C7 that circulates the movers 21 and 21 of the Y linear motor 15 to control the temperature, and a trim motor 72 and 72. Circulating systems C 8 and C 8 that circulate and control the temperature, a circulating system C 9 that circulates the Y voice coil motor 17 and temperature control, and a circulating system that controls the temperature by circulating the X voice coil motor 17 X It is branched into a plurality of branch channels with the circulation system C10.

Each of the circulation systems C7 to C10 is provided with a valve (adjustment means) 80 which is located upstream of each motor and adjusts the flow rate of the refrigerant. One of the circulation systems C7 is provided near the mover 21 and detects a refrigerant temperature before circulating through the mover 21 (first temperature detecting means) 76a. A temperature sensor (second temperature detecting means) 76b for detecting the coolant temperature after the circulation of the child 21 is provided. In the circulation system C6, a heater 78 is provided downstream of the pump 74, and the refrigerant temperature before circulating through the wafer stage 5 and the refrigerant temperature after circulating through the wafer stage 5 are controlled. Temperature sensors (first detecting means) 79a and 79b for detecting the respective temperatures are provided, and the detection results of the temperature sensors 79a and 79b are output to the controller 77. The controller 77 averages the detection results of the input temperature sensors 79a and 79b, and controls the driving of the heater 78 based on the obtained refrigerant temperature, thereby reducing the temperature of the wafer stage 5 to, for example, 2 Control (manage) to 3 ° C ± 0.1 ° C. The refrigerant circulated through the stages 2 and 5 in the circulation systems C5 and C6 joins after being cooled by the heat exchanger 70.

As for the position of the temperature sensors 79a and 79b, as with the sensors 76a and 76b described above, in any of the sensors, the temperature control target (the wafer stage 5, more accurate In other words, it is desirable to place it as close as possible to the motor that drives the wafer stage 5 described later. However, if it is not possible to get close to the temperature control target due to restrictions on the arrangement or the influence of the magnetic force of the motor, etc., if the temperature control target is within the range (location) that is not affected by external heat, It is also possible to provide them at some distance.

Regarding the arrangement position of the sensors 79a and 79b, it can be said that it is the same as that described for the arrangement of the sensors 76a and 76b, so the description is omitted here.

Next, the temperature control system for the wafer stage 5 will be described in detail.

As shown in FIG. 6, the circulation system C 6 includes the movers 36 and 36 of the linear motor 33. The circulation system is divided into a circulation system C11, C11 that circulates and controls the temperature, and a circulation system C12 that circulates the X linear motor 35 to control the temperature. Each of the circulation systems C11 to C12 is provided with a valve 84 located upstream of each motor and for adjusting the flow rate of the refrigerant. In addition, one of the circulation systems CI 1 includes the sensors 79 a and 79 described above for detecting the refrigerant temperature before circulating through the mover 36 and the refrigerant temperature after circulating through the mover 36, respectively. b is provided.

The circulating systems CI 3 to C 15 are also provided for the three voice coil motors 81 to 83 for performing leveling adjustment (and focus adjustment) of the wafer stage 5 (sample stage ST). A pipe 85 is provided in each circulating system with a valve 85 that is located upstream of the motor and regulates the flow rate of the refrigerant. The driving frequency of the voice coil motors 81 to 83 is determined by the linear motors 33 and 3. 5 and the amount of heat generated during operation is small, so that these circulating systems C13 to C15 are temperature-controlled by the refrigerant branched from the circulating system C1 of the first control system 61. . The circulating system for controlling the temperature of not only the voice coil motors 81 to 83 but also a motor having a small heat generation during driving (for example, the trim motor 72 and the X voice coil motor 17X described above) includes a first control system. Temperature control may be performed using a refrigerant branched from the circulation system C 1 of FIG.

The temperature sensors 66, 69, 76a, 76b, 79a, 79b are ± 0.1 in the present embodiment. Although a sensor with an accuracy capable of detecting C is used, the temperature control accuracy required for the reticle stage 2 and the wafer stage 5 is ± 0.1 ° C in the second control system 62, so the temperature sensor 76 a , 76b, 79a, and 79b, it is also possible to use a temperature sensor having a detection capability corresponding to this accuracy. Regarding the temperature measurement sampling interval by the temperature sensor, for example, when the control accuracy is severe or when the temperature change is large, the sampling interval is shortened, and the required temperature control accuracy and the projection to be controlled It is also preferable to change according to the temperature change (heat generation) of the optical system PL and stages 2 and 5.

In addition, in the present embodiment, each temperature sensor is disposed inside a flow path (pipe) so that the refrigerant temperature can be directly measured. (The detector is suspended near the center of the cross section of the pipe.) State). In this case, since the detecting portion of the sensor does not contact the pipe wall, the external environment is less likely to be adversely affected through the pipe wall. Further, the temperature sensor may be configured to be replaceable. In this case, an insertion port is provided in the pipe, and the pipe is detachable through the inlet, or the temperature sensor is fixed to the pipe by welding or the like, and a part of the pipe including the temperature sensor is replaceable. Can be adopted. Furthermore, it is also possible to install a temperature sensor on the outer surface of the pipe and measure the refrigerant temperature via the pipe.

In the exposure apparatus 1 having the above configuration, a predetermined rectangular illumination area on the reticle R is illuminated with uniform illuminance by exposure illumination light from the illumination optical system Iu during exposure. In synchronization with the scanning of the reticle R in the Y direction with respect to the illumination area, the wafer W is scanned with respect to an exposure area conjugate with respect to the illumination area and the projection optical system PL. As a result, the illumination light transmitted through the pattern area of the reticle R is reduced to 1/4 times by the projection optical system PL, and irradiated onto the wafer W coated with the resist. Then, the pattern of the reticle R is sequentially transferred to the exposure area on the wafer W, and the entire surface of the pattern area on the reticle R is transferred to the shot area on the wafer W by one scan.

When the reticle coarse movement stage 16 moves in the + Y direction, for example, the stator 20 moves in the −Y direction, so that the momentum is preserved and the reaction force accompanying the movement of the reticle coarse movement stage 16 is reduced. This cancels out and prevents the position of the center of gravity from changing. Also, at this time, the trim motor 72 is operated so that the stator 20 can reach a predetermined position against the coupling between the mover 21 and the stator 20.

In these series of exposure processes, the illumination light generates heat in the projection optical system PL (heat absorption in the projection optical system PL due to the illumination light irradiation), and the alignment light generates heat in the alignment system AL ( In addition to heat absorption in the alignment optical system due to alignment light irradiation, heat is generated from each motor as the stages 2 and 5 are driven. For the first control system 61, the controller 67 sets conditions (first circulation condition) for circulating the refrigerant based on the detection results of the temperature sensors 66, 69, and drives the heater 71. By controlling, the temperature of the projection optical system PL and the alignment system AL is controlled within a range of ± 0.01 ° C. Also, for the second control system 62, the controller 77 Based on the detection results of the temperature sensors 76a, 76b, 79a, and 79b, the conditions for circulating the refrigerant (second circulation conditions) are set, and the heaters 75, 78 are driven. By controlling the temperature, the reticle stage 2 and the wafer stage 5 are each temperature-controlled within a range of ± 0.1 ° C.

More specifically, for the reticle stage 2, first, the controller 77 simply averages the refrigerant temperatures detected by the temperature sensors 76a and 76b, and based on the obtained refrigerant temperature, the first temperature management unit Adjust and manage the drive of heater 75 Here, the temperature sensors 76a and 76b are provided in the circulation system C7 that circulates the mover 21 of the Y linear motor 15 that has the largest amount of drive and the largest amount of heat generation, and The temperature of the circulation system C8 to C10 is controlled based on the circulation system C7. For this reason, in the present embodiment, the correlation between the process and the optimal refrigerant flow rate is obtained and stored in advance by experiments, simulations, and the like, and based on the stored information, each circulation system C7 to Adjust valve 80 for C10.

Here, the heat generation factors to be considered in the process include various driving states of each motor 15, 17 X, 17 Y, and 72, that is, the driving amount and speed of each motor, the number of rotations, and other factors. A state when driven in combination with a motor is exemplified. Therefore, for the voice coil motors 17Χ and 17 that generate a small amount of heat (or drive) in the process, the refrigerant flow rate is reduced and the heat generation (or drive) is large. By adjusting the valve 80 so that the coolant flow rate is increased for 72, appropriate temperature control according to the output (heat generation) of each motor becomes possible. In addition, as a method of adjusting the valve 80, a method in which an operator adjusts each process based on the stored information or a driving mechanism of the valve 80 is provided, and the process is performed based on the stored information. It is possible to adopt a method in which the controller 77 adjusts this drive mechanism for each time. The target to be adjusted for each process is not limited to the flow rate, and the coolant temperature (the temperature set by the heater) may be changed for each process.

Similarly, for the wafer stage 5, the controller 77 simply averages the refrigerant temperatures detected by the temperature sensors 79a and 79b, and based on the obtained refrigerant temperature, Adjusts and manages the operation of heaters 78 as a temperature management unit. Here, the temperature sensors 79a and 79b are provided in the circulating system CI1 that circulates through the mover 36 of the linear motor 33 that has the largest amount of driving and generates a large amount of heat. The temperature of 2 is controlled based on the circulation system C 11. Therefore, in the present embodiment, the correlation between the process and the optimum refrigerant flow rate is obtained and stored in advance by experiments, simulations, and the like, and based on the stored information, each circulation system C 11 Adjust the valves 85, C12. As in the case of the reticle stage 2, the valve 85 can be adjusted manually or automatically.

In addition, the temperature of the voice coil motors 81 to 83 provided on the wafer stage 5 is controlled by the circulation system CI 3 to C 15 of the first control system 61 because the amount of heat generated is very small. In addition, the correlation between the process and the optimal refrigerant flow rate is obtained and stored in advance by experiments, simulations, and the like, and the valves of each circulation system C13 to C15 are provided for each process based on the stored information. Adjust the flow rate of 8 5 by manual adjustment by the operator or automatic adjustment by the controller 6 7.

As described above, in the present embodiment, since the first control system 61 and the second control system 62 have different setting capabilities in the temperature range when setting the refrigerant temperature, the required temperature control accuracy is required. However, the temperature can be controlled and managed independently for the projection optical system PL and the stages 2 and 5, which are different from each other, and the optimal cooling conditions can be set according to the heat value of each device. Therefore, it is possible to suppress the baseline fluctuation that occurs when the temperature is not sufficiently controlled, and to suppress the deterioration of the overlay accuracy.

Further, in the present embodiment, in reticle stage 2 and wafer stage 5, the refrigerant temperature is measured not for all motors but for the motor having the largest amount of heat generation, and other motors are determined based on the refrigerant temperature. Since the temperature of the circulating system is controlled, it is not necessary to provide a temperature and temperature sensor for each motor, and the size and cost of the device can be reduced.

By the way, since the refrigerant flowing through each of the motors provided on the reticle stage 2 and the wafer stage 5 is temperature-controlled and managed by the same second control system 62, the refrigerant inlet side to each motor Temperature (Refrigerant temperature before circulating through each motor Degree) is the same temperature regardless of the motor, but the outlet temperature of the refrigerant for each motor (refrigerant temperature after flowing through each motor) differs for each motor according to the degree of heat generation of each motor . Therefore, in order to keep the average temperature of the refrigerant circulating in each motor (the average temperature of the refrigerant at the inlet and the outlet of the motor) at a constant desired value for all motors, the outlet side of each motor is required. It is necessary to control the temperature of the refrigerant at a constant value for any motor. Therefore, in order to perform more accurate temperature control, a temperature sensor (outlet temperature sensor) that measures the refrigerant temperature at least at the outlet side of each motor is provided (the temperature sensor that measures the inlet side temperature is Only one motor is typically provided for the motor that generates the largest amount of heat.) However, the flow rate of the refrigerant circulated through each motor is adjusted so that the outlet temperature of the refrigerant at each motor becomes a constant value. The motor may be configured to be adjusted by a corresponding valve for each motor. In setting the flow rate, the stage is driven under running conditions (eg, a condition where the number of exposure shots is large and the stage movement is large), or when the stage is driven (running). Under a typical exposure condition (stage driving state), when the stage is driven, the flow rate of the refrigerant circulating through each motor is set so that the above-mentioned outlet temperature becomes a constant value. It is desirable to do. If space and price allow, a temperature sensor for measuring the refrigerant temperature on the inlet side of the motor may be provided for each motor.

As shown in Fig. 7, a micro device such as a semiconductor device has a step 201 for designing the function and performance of the micro device, a step 202 for manufacturing a reticle R based on the design step, and a silicon material. Step of manufacturing wafer W from wafer 203, Exposure processing step 204 of projecting and exposing the pattern of reticle R onto wafer W by projection exposure apparatus 1 of the above-described embodiment, and developing wafer W, device assembly It is manufactured through steps (including dicing process, bonding process, and package process) 205 and inspection step 206.

Further, in the above embodiment, the correlation between the process and the optimum refrigerant flow rate is determined and stored in advance, and the valve of each circulation system is adjusted for each process based on the stored information. However, besides this method, for example, the temperature In addition to providing a sensor, a calculation means for calculating the ratio of the amount of heat generation among a plurality of motors is provided, and the flow rate of the refrigerant circulating through the motors is adjusted according to the ratio of the amount of heat generation calculated based on the detected refrigerant temperature. It is also possible.

FIG. 8 is a view showing a second embodiment of the exposure apparatus of the present invention. In this figure, the same elements as those of the first embodiment shown in FIGS. 1 to 7 are denoted by the same reference numerals, and the description and illustration thereof will be simplified.

As shown in this figure, in the present embodiment, the circulation system C 1 of the first control system 61 controls the projection optical system and the alignment system (and the leveling adjustment system of the wafer stage 5 described above) as a temperature control object. The circulating system C5 of the second control system 62 controls the reticle stage 2 for temperature control, and the third control system 86 provided independently of the first and second control systems 61 and 62. The circulating system C6 controls the wafer stage 5 for temperature control. In FIG. 8, those having the same functions as the evaporator 65 and the heater 71 shown in FIG. 4 are simplified as a temperature controller 87. Similarly, those having functions equivalent to those of the heat exchanger 70 and the heaters 75 and 78 shown in FIG. 4 are schematically illustrated as temperature controllers 88 and 89. Also, in Fig. 4, two temperature sensors 76a, 76b and 79a, 79b are arranged for stages 2 and 5, respectively. This is shown as 9.

Regarding the temperature sensors 76 and 79, as in the first embodiment described above, of the plurality of motors controlled by the second control system 62 and the third control system 86, respectively, the heat generation amount is the largest. Motors are selected for each control system, and temperature sensors are installed for each of the selected motors (at two points on the inlet side and the outlet side of each motor). The same temperature control of the refrigerant as described in the first embodiment may be performed.

Further, as described as a modified example of the first embodiment, each of the plurality of motors whose temperature is controlled by the second control system 62 and the plurality of motors whose temperature is controlled by the third control system 86 are respectively controlled. A temperature sensor is installed on the outlet side (the inlet side temperature sensor is installed for only one typical motor in each control system), and the outlet side temperature is controlled to a constant value (second control). The system circulates through each motor provided on reticle stage 2. The third control system 86 controls each motor so that the outlet temperature of the refrigerant circulating through each motor provided on the wafer stage 5 is maintained at a constant value so that the outlet temperature of the refrigerant is constant. The flow rate of the flowing refrigerant may be adjusted by each valve.

In the present embodiment, in the first control system 61, the temperature sensor 69, which is the third detecting means, detects the temperature of the refrigerant circulating in the projection optical system PL, and the controller 67 detects the refrigerant based on the detection result. By setting the circulating condition (third circulating condition) and controlling the driving of the temperature controller 87, the temperature of the projection optical system PL is controlled within a range of ± 0.01 ° C. Further, in the second control system 62, the temperature sensor 76 detects the temperature of the refrigerant circulating in the reticle stage 2, and the controller 77 controls the driving of the temperature controller 88 based on the detection result. Control the temperature of reticle stage 2 within the range of ± 0.1 ° C. Similarly, in the third control system 86, the temperature sensor 79 detects the temperature of the refrigerant circulating in the wafer stage 5, and the controller 90 controls the drive of the temperature controller 89 based on the detection result. The temperature of the wafer stage 5 is controlled within a range of ± 0.1 ° C.

As described above, in the present embodiment, in addition to obtaining the same operation and effect as in the first embodiment, the projection optical systems PL and PL are independently controlled by the control systems 61, 62, and 86, respectively. Since the temperature of the reticle stage 2 and the wafer stage 5 are controlled, it is possible to perform more accurate temperature management according to the heat generation amount of each control target.

FIG. 9 shows a third embodiment of the exposure apparatus according to the present invention.

In the present embodiment, the first control system 61 controls the projection optical system PL and the wafer stage 5 as a temperature control target, and the second control system 62 controls the reticle stage 2 as a temperature control target. In the first control system 61, the temperature of a circulation system C1 circulating through the projection optical system P L and the alignment system A L and a circulation system C 6 circulating through the wafer stage 5 are controlled by a single temperature controller 87. In this temperature control, the temperature of the refrigerant circulating in the projection optical system PL is detected by the temperature sensor 69, and the controller 67 controls the temperature controller 8 based on the detected result.

It is implemented by controlling the drive of 7. In this case, the temperature of the wafer stage 5 is controlled within a range of ± 0.01 ° C., similarly to the projection optical system PL. In addition,

2 In the control system 62, the reticle stage 2 is independent of the first control system 61, and The temperature will be controlled in the range of 0.1 ° C.

Also in the present embodiment, it is possible to control the temperature of the reticle stage 2 having the largest amount of heat independently of the projection optical system PL and the wafer stage 5 having relatively small amounts of heat. Optimal cooling conditions can be set accordingly. In addition, compared to the second embodiment, the first control system 61 can control the refrigerant temperatures of the two circulation systems C1 and C6, so that the device configuration can be simplified.

FIG. 10 is a view showing a fourth embodiment of the exposure apparatus of the present invention. In this figure, only the temperature control system related to reticle stage 2 is shown.

As shown in this figure, the second control system 62 includes a temperature sensor 91, a controller 77, and a temperature controller 88 shown in FIGS. , 92 and a Peltier element 93 as a second regulator. Peltier element 93 is arranged closer to reticle stage 2 than temperature controller 88, and its drive is controlled by controller 77. The temperature sensor 91 is arranged on the upstream side of the Peltier element 93, and the temperature sensor 92 is arranged on the downstream side of the Peltier element 93, and the refrigerant temperature detected by each of the temperature sensors 91 and 92 is determined by the controller. Output to 7 7. The controller 77 controls the driving of the temperature controller 88 based on the temperature detection result of the temperature sensor 76, and controls the driving of the Peltier element 93 based on the temperature detection results of the temperature sensors 91 and 92. I do. Other configurations are the same as those of the second and third embodiments.

In the above configuration, the controller 77 supercools the refrigerant temperature of the circulation system C5 to a temperature lower than a predetermined temperature by controlling the temperature controller 88. Then, the controller 77 raises the refrigerant to a predetermined temperature by energizing the Peltier element 93 based on the refrigerant temperature detected by the temperature sensors 91 and 92.

In the present embodiment, even if the temperature rises sharply when driving reticle stage 2, it is possible to control the temperature to a predetermined temperature by circulating the supercooled refrigerant, and a rapid temperature change of the equipment can be achieved. Can be easily dealt with. The configuration is not limited to the configuration in which the refrigerant is supercooled by the temperature controller 88 and heated by the Peltier element 93, but may be a configuration in which the refrigerant is overheated by the temperature controller 88 and cooled by the Peltier element 93. Ma 03 03003

. twenty five

When heating the supercooled refrigerant, a heater may be used instead of the Peltier element 93.

Next, a fifth embodiment of the exposure apparatus of the present invention will be described.

For example, in the third embodiment shown in FIG. 9, in the first control system 61, the controller 67 controls the driving of the temperature controller 87 based on the detection result of the temperature sensor 69, and the second control system 62 In the embodiment, the controller 77 controls the driving of the temperature controller 88 based on the detection result of the temperature sensor 76, but in the present embodiment, these temperature sensors 69, 76 are not provided. The controller 67 calculates the amount of heat generated by driving the wafer stage 5 based on the data (exposure recipe) relating to the exposure processing, and sets the coolant temperature based on the calculated amount of heat, thereby setting the temperature controller 87 Control the drive. Similarly, in the second control system 62, the controller 77 calculates the amount of heat generated by driving the reticle stage 2 based on the exposure data, and sets the coolant temperature based on the calculated amount of heat. Temperature controller 8 8 Drive control.

As a specific control method, for example, the operator (user) selects a process program on the OA panel, and based on the selected process information and the information registered in the exposure data, the amount of power required to drive the motor on the calculation circuit The calorific value is calculated and the driving of the temperature controllers 87 and 88 is controlled.

In the present embodiment, since there is no need to provide a temperature detecting means such as a temperature sensor, it is possible to contribute to a reduction in the size and cost of the device. The ratio between the drive voltage applied to the motor and the amount of heat generation (change in temperature) may be determined for each motor, and the flow rate may be adjusted in accordance with the ratio to the drive voltage.

In each of the above embodiments, the temperature of the controlled object is controlled by adjusting the flow rate of the refrigerant. However, the present invention is not limited to this. At least one of the temperature, the flow velocity, and the flow rate of the refrigerant is used. One. In the above embodiment, the temperature controller and the pump for driving the refrigerant are partially shared. However, they are separated for each control target (circulation system) or shared by all circulation systems. Various configurations such as can be adopted. For example, when both a cooler and a heater are provided, the heater may be shared and a cooler may be provided for each control target. In this case, the final temperature adjustment must take place in the cooler. And '

Further, in each of the above embodiments, the configuration is such that the refrigerant temperature before circulating the stages 2 and 5 and the refrigerant temperature after circulating are simply averaged, but a weighted average may be used. The following method can be adopted as a method of weighted averaging. (1) If the distance from the heat source such as a motor to the installation position of the inlet-side temperature sensor is different from the distance from the heat source to the installation position of the outlet-side temperature sensor, the closer the distance, the smaller the temperature sensor Weighting is performed according to the distance, such as increasing the weight. (2) If the material that forms the vicinity of the inlet of the heat source such as a motor is different from the material that forms the vicinity of the outlet, it is weighted according to the material of the material, such as thermal conductivity. The greater the conductivity, the greater the weight of the material). (3) If another heat source exists near the inlet or outlet, weighting is performed according to the presence or absence of the different heat source and the amount of heat generated. For example, when another heat source exists on the flow path, the weight of the temperature sensor output on the side closer to the other heat source is increased. If another heat source exists outside the flow path, the heat generated by the other heat source is transmitted to the temperature sensor via air, so the weight of the output of the temperature sensor near the other heat source is increased. (4) At the time of baseline measurement, the detected temperature of the inlet-side temperature sensor, the detected temperature of the outlet-side temperature sensor, the control temperature of the refrigerant (control temperature calculated by a simple average), and the measured baseline amount (or baseline) And the storage operation is repeated for each baseline measurement. Then, based on the plurality of accumulated data sets, an estimation is performed to determine which weight is given to the inlet-side temperature or the outlet-side temperature and how much the baseline fluctuation is reduced. Then, a weighted average is performed based on the estimated weights.

In the above embodiments, the same type of refrigerant (HFE) is used. However, different refrigerants are used for each circulating system according to the temperature control accuracy required for each circulating system and the installation environment. You may.

In each of the above embodiments, the temperature is controlled by the refrigerant circulating in one direction for one temperature control target (motor or the like). However, the present invention is not limited to this, and the temperature is controlled in a plurality of directions. The temperature may be controlled using a circulating refrigerant.

For example, as shown in Fig. 11 (A), the control target 2 1 (here, as an example, In this case, two circulating systems C 7a and C 7b having different circulation directions are connected to each other, and the circulating systems C 7a and C 7b are connected to each other. Refrigerant is circulated from opposite directions (the refrigerant inlet and outlet are reversed between the two circulation systems). With this configuration, when only one circulation system is provided, the temperature gradient that may occur in the control target 21 (between the inlet side and the outlet side of one circulation system) may be reduced. The temperature can be controlled more accurately and accurately.

In addition, as shown in Fig. 11 (B) and Fig. 11 (C), the temperature control section (flow path, piping) is subdivided and the temperature of the control target is controlled, so that the temperature on the control target is controlled. There can be no gradient. In Fig. 11 (B), three different circulation systems (flow paths, pipes) C7c, C7d, and C7e are provided for the control target 21 as shown in the figure, and each circulation system is controlled. The refrigerant is circulated in the direction of the arrow in the figure. Also, in Fig. 11 (C), four different circulation systems (flow paths, pipes) C7f, C7g, C7h, and C7i are provided for the control target 21 as shown in the figure. The refrigerant is circulated in each circulation system in the direction of the arrow in the figure. By adopting such a configuration in which the temperature control is segmented, the temperature gradient on the control target can be eliminated.

In addition, as shown in the circulation system C 7 c and C 7 e in FIG. 11 (B) or the circulation system C 7 f and C 7 h or the circulation system C 7 g and C 7 i in FIG. 11 (C), In the disposed circulation system, it is desirable to make the circulation direction of the refrigerant reverse as shown in the figure from the viewpoint of eliminating the temperature gradient.

In the examples of Figs. 11 (A) to 11 (C), the temperature sensors 76a and 76b are provided on the inlet and outlet sides of each of the circulation systems C7a to C7i. However, a temperature sensor may be provided for only one circulating system, or a temperature sensor may be provided only for the outlet side of each circulating system. How to use these temperature sensors is the same as in each of the above embodiments.

The configurations shown in Figs. 11 (A) to 11 (C) are particularly effective when the control target is large (long) or when the heat generation amount (drive amount) of the control target is large. An example of such a control target is a Y linear motor 15 of the reticle coarse movement stage 16. (Motor driven in scan direction), stator 20 extending in Y direction, or mover 36 or stator 3 7 of linear motor 33 on wafer stage. . The configurations shown in FIGS. 11 (A) to 11 (C) are also effective especially for a control target where a temperature gradient-free state is required. Such control targets include, for example, a drive source arranged near the wafer / reticle (for example, voice coil motor 8:! ~ 83, or a reticule / Y voice coil motor 17 of the mounting stage). Υ etc.) can be considered. The locations to which the configuration of FIG. 11 is applied are not limited to the locations described here, and the configuration shown in FIG. 11 may be applied to locations where a situation without a temperature gradient is desired. .

The substrate of the present embodiment includes not only a semiconductor wafer W for a semiconductor device, but also a glass substrate for a liquid crystal display device, a ceramic wafer for a thin film magnetic head, or a mask or reticle used in an exposure apparatus. Original plate (synthetic quartz, silicon wafer) etc. are applied.

As the exposure apparatus 1, a step-and-scan running exposure apparatus (scanning stepper; US Pat. No. 5,473,410) in which a reticle R and a wafer W are synchronously moved and a pattern of the reticle R is scanned and exposed. In addition, the present invention is also applicable to a step-and-repeat type projection exposure apparatus (stepper) that exposes the pattern of the reticle R while the reticle R and the wafer W are stationary and sequentially moves the wafer W in steps. Can be.

The type of the exposure apparatus 1 is not limited to an exposure apparatus for manufacturing a semiconductor device that exposes a semiconductor device pattern onto a wafer W, and is not limited to an exposure apparatus for manufacturing a liquid crystal display element, a thin film magnetic head, an image pickup device (CCD), or the like. It can be widely applied to exposure devices for manufacturing reticles and the like.

In addition, emission lines (g-line (433 nm), h-line (404.7 nm), i-line (365 nm)), r F excimer laser (248 nm), Ar F excimer laser (193 nm), F ₂ laser (157 nm), as well as charged particle beams such as X-rays and electron beams Can be done. For example, when using an electron beam, use an electron gun as a thermionic emission type lantern. Kisabolite (L a B ₆ ) and tantalum (T a) can be used. Further, when an electron beam is used, a configuration using a reticle R may be used, or a configuration in which a pattern is directly formed on a wafer without using the reticle R may be used. Alternatively, a high frequency such as a YAG laser or a semiconductor laser may be used.

The magnification of the projection optical system PL may be not only a reduction system but also any of an equal magnification system and an enlargement system. Further, as the projection optical system PL, when far ultraviolet rays such as an excimer laser are used, a material which transmits far ultraviolet rays such as quartz or fluorite is used as a glass material, and when a F ₂ laser or X-ray is used, a catadioptric system is used. An optical system of a refraction system (a reticle R of a reflection type is also used), and when an electron beam is used, an electron optical system composed of an electron lens and a deflector may be used as the optical system. It goes without saying that the optical path through which the electron beam passes is in a vacuum state. Further, the present invention can also be applied to a proximity exposure apparatus that exposes the pattern of the reticle R by bringing the reticle R and the wafer W into close contact with each other without using the projection optical system PL.

When using a linear motor (see USP5, 623, 853 or USP5, 528, 118) for the wafer stage 5 and reticle stage 2, either an air levitation type using an air bearing or a magnetic levitation type using a Lorentz force or a reactor tanker May be used. Further, each of the stages 2 and 5 may be of a type that moves along a guide or a guideless type that does not have a guide.

The drive mechanism for each of the stages 2 and 5 consists of a magnet unit (permanent magnet) with a two-dimensionally arranged magnet and an armature unit with a two-dimensionally arranged coil. A driving flat motor may be used. In this case, one of the magnet unit and the armature unit is connected to the stages 2 and 5, and the other of the magnet unit and the armature unit is on the moving surface side (base) of the stages 2 and 5. It may be provided.

As described above, the exposure apparatus 1 according to the embodiment of the present invention controls various subsystems including the respective components listed in the claims of the present application so as to maintain predetermined mechanical accuracy, electrical accuracy, and optical accuracy. Manufactured by assembling. Before and after this assembly, achieve the optical accuracy of various optical systems to ensure these various accuracy. Adjustments to achieve mechanical accuracy for various mechanical systems, and adjustments to achieve electrical accuracy for various electrical systems. The process of assembling the exposure apparatus from various subsystems includes mechanical connection, wiring connection of electric circuits, and piping connection of pneumatic circuits among the various subsystems. It goes without saying that there is an assembly process for each subsystem before the assembly process from these various subsystems to the exposure device. When the process of assembling the various subsystems into the exposure apparatus is completed, comprehensive adjustments are made to ensure various precisions of the entire exposure apparatus. It is desirable to manufacture the exposure equipment in a clean room where the temperature and cleanliness are controlled. INDUSTRIAL APPLICABILITY As described above, according to the present invention, it is possible to control and manage the temperature independently even for devices having different required temperature control accuracy. Since the optimal cooling conditions can be set according to the amount of heat generated, it is possible to suppress the baseline fluctuation caused by the temperature control not being performed and the deterioration of the overlay accuracy. Further, the present invention has an effect that it can contribute to miniaturization and cost reduction of the device.

Claims

The scope of the claims

1. An exposure apparatus that projects a pattern image of a reticle held on a reticle stage onto a substrate held on a substrate stage via a projection optical system, and sets the temperature of the first liquid, A first control system configured to circulate the temperature-set first liquid to at least one of the projection optical system and the substrate stage for controlling the temperature of the object;

A second control system that sets the temperature of the second liquid independently of the first control system, circulates the set second liquid to the reticle stage, and controls the temperature of the reticle stage. Has,

The first and second control systems have different setting abilities in terms of the size of the temperature range when setting the temperature of the liquid.

2. The exposure apparatus according to claim 1, wherein

The object is the substrate stage,

The first control system calculates the amount of heat generated by driving the substrate stage, and sets the temperature of the first liquid based on the calculated amount of heat,

The second control system calculates the amount of heat generated by driving the reticle stage, and sets the temperature of the second liquid based on the calculated amount of heat.

3. The exposure apparatus according to claim 1 or 2, wherein

First detection means for detecting a temperature of the first liquid before circulating through the object and a temperature of the first liquid after circulating the object, respectively;

And a second detection means for detecting a temperature of the second liquid before circulating through the reticle stage and a temperature of the second liquid after circulating through the reticle stage, respectively.

The first control system sets a temperature of the first liquid based on a detection result of the first detection unit, The second control system sets the temperature of the second liquid based on the detection result of the second detection means.

4. The exposure apparatus according to any one of claims 1 to 3, wherein

The reticle stage has a plurality of driving sources,

The second control system sets the temperature of the second liquid based on information on a heat generation amount of a predetermined drive source having the largest heat generation amount among a plurality of drive sources on the reticle stage.

5. The exposure apparatus according to claim 4, wherein

The second control system includes: a plurality of branch flow paths that circulate the temperature-set second liquid to each of the plurality of drive sources;

It is installed at a position on the plurality of branch channels before the second liquid is supplied to each of the plurality of driving sources, and adjusts a flow rate of the second liquid supplied to each of the driving sources. And a plurality of adjusting means.

6. The exposure apparatus according to claim 5, wherein

The second control system further includes a calculating unit that calculates a ratio of a calorific value between the plurality of drive sources,

The plurality of adjusting means adjust the flow rates of the second liquid respectively circulated to the plurality of driving sources according to the calculated ratio of the calorific values.

7. The exposure apparatus according to any one of claims 4 to 6, wherein

First temperature detection means provided in the vicinity of the predetermined drive source and configured to detect a temperature of the second liquid before being circulated to the predetermined drive source;

The first drive source is provided near the predetermined drive source, and the second drive source after circulating the predetermined drive source is provided.

2 having a second temperature detecting means for detecting the temperature of the liquid,

The second control system, based on the detection results of the first and second temperature detecting means, Set the temperature of the second liquid.

8. The exposure apparatus according to any one of claims 1 to 7, wherein

The first control system sets at least the projection optical system as a control target, sets the temperature of the third liquid independently of the first and second control systems, and sets the temperature of the third liquid to the third liquid. And a third control system that circulates through the substrate stage to control the temperature of the substrate stage.

9. The exposure apparatus according to any one of claims 1 to 7, wherein the first control system controls both the projection optical system and the substrate stage.

10. An exposure apparatus that projects a pattern image of a reticle held on a reticle stage onto a substrate held on a substrate stage via a projection optical system, wherein the projection optical system, the substrate stage, A first circulation condition for circulating the first liquid to at least one of the objects is set, and the first liquid is circulated under the first circulation condition to reduce a temperature of the object. A first control system to be controlled, and a second circulation condition for circulating the second liquid to the reticle stage, independently of the first circulation condition, and under the second circulation condition. A second control system for circulating the second liquid to control the temperature of the reticle stage; a temperature of the first liquid before circulating the object; and a second control system after circulating the object. 1 liquid, temperature and First detecting means for detecting,

A temperature of the second liquid before circulating through the reticle stage; and a second detection means for detecting a temperature of the second liquid after circulating through the reticle stage, respectively.

The first control system sets the first circulation condition based on a detection result of the first detection unit,

The second control system sets the second circulation condition based on the detection result of the second detection means.

11. The exposure apparatus according to claim 10, wherein

The first circulation condition includes at least one of a temperature, a flow rate, and a flow rate of the first liquid set before circulating the first liquid through the object,

The second circulation condition includes at least one of a temperature, a flow rate, and a flow rate of the second liquid set before circulating the second liquid through the reticle stage.

12. The exposure apparatus according to claim 10 or 11, wherein

The reticle stage has a plurality of driving sources,

The second detection means is provided in the vicinity of a predetermined drive source having the largest heat generation amount among the plurality of drive sources on the reticle stage, and the second detection unit before being circulated to the predetermined drive source. A first sensor for detecting a temperature of the liquid, a second sensor provided near the predetermined drive source and detecting a temperature of the second liquid after being circulated with respect to the predetermined drive source; including.

13. The exposure apparatus according to claim 12, wherein

The second control system includes: a plurality of branch channels that circulate the temperature-set second liquid to each of the plurality of driving sources;

14. The exposure apparatus according to claim 13, wherein

15. The exposure apparatus according to any one of claims 10 to 14, wherein the first control system is configured to control at least the substrate stage,

A third circulation condition for circulating the third liquid with respect to the projection optical system is set independently of the first and second control systems, and the third liquid is circulated under the third circulation condition. A third control system for controlling the temperature of the projection optical system by circulating

Third detecting means for detecting the temperature of the third liquid circulated through the projection optical system, further comprising:

The third control system sets the third circulation condition based on a detection result of the third detection means.

16. An exposure apparatus that projects a pattern image of a reticle held on a reticle stage onto a substrate held on a substrate stage via a projection optical system, wherein the reticle stage and the substrate stage include: A first control system comprising a plurality of drive sources, and a temperature control of the plurality of drive sources and the projection optical system having a heat generation amount or a temperature change amount within a first predetermined amount as a first control target;

Of the plurality of drive sources and the projection optical system, those having a heat generation amount or a temperature change amount larger than a first fixed amount are set as a second control target, and a second temperature control is performed independently of the first control system. And a control system.

17. The exposure apparatus according to claim 16, wherein

The first control system sets a first circulation condition when circulating the first liquid with respect to the first control target, and circulates the first liquid under the first circulation condition to form the first liquid. 1 Control the temperature of the controlled object,

The second control system sets a second circulation condition when circulating the second liquid with respect to the second control target, and circulates the second liquid under the second circulation condition to perform the second circulation. 2 Control the temperature of the control target.

18. The exposure apparatus according to claim 17, wherein The first circulation condition includes at least one of a temperature, a flow rate, and a flow rate of the first liquid set before circulating the first liquid through the object,

19. The exposure apparatus according to claim 17 or 18, wherein

A plurality of control targets included in the first control target, provided near the control target having the largest amount of heat generation or the temperature change, and a first detection unit that measures the temperature of the first liquid;

And a second detection unit that is provided near the control target having the largest heat generation amount or the temperature change amount among the plurality of control targets included in the second control target, and that measures the temperature of the second liquid. Have

The first and second control systems respectively set the first and second circulation conditions based on detection results by the first and second detection means.

20. The exposure apparatus according to any one of claims 16 to 19,

The first control target includes the projection optical system and a part of a driving source provided on the substrate stage,

The second control target includes a plurality of driving sources provided on the reticle stage.

21. The exposure apparatus according to any one of claims 16 to 20, wherein

The second control target includes a plurality of drive sources provided on the reticle stage, and a plurality of drive sources provided on the substrate stage.

A first temperature management unit that manages temperatures of a plurality of driving sources provided on the reticle stage;

A second temperature management unit that manages the temperature of the plurality of driving sources provided on the substrate stage independently of the first temperature management unit.

22. The exposure apparatus according to any one of claims 4 or 10 to 15 or 19,

The first control system sets the setting based on an average temperature of a temperature of the first liquid before circulating the control target and a temperature of the first liquid after circulating the control target. Do

The second control system performs the setting based on an average temperature of a temperature of the second liquid before circulating through the reticle stage and a temperature of the second liquid after circulating through the reticle stage. .

23. The exposure apparatus according to any one of claims 1 to 22, wherein

A first controller for supercooling or overheating the temperature of the second liquid at a temperature lower than a predetermined temperature;

A second adjuster that is installed closer to the reticle stage than the first adjuster and adjusts the temperature of the second liquid, the temperature of which is set by the first adjuster, to the predetermined temperature.

24. The exposure apparatus according to any one of claims 1 to 23, wherein the liquids used for the temperature control are the same type of liquid.

25. The exposure apparatus according to any one of claims 1 to 24, wherein at least one of the first control system and the second control system is the one for one control target. It has multiple circulation paths for circulating liquid.

26. The exposure apparatus according to claim 25, wherein

Circulation directions of the refrigerant circulating through the plurality of circulation paths with respect to the control target are different from each other for each of the circulation paths.

2 7. A device manufacturing method, And transferring the pattern formed on the reticle onto the substrate using the exposure apparatus according to any one of claims 1 to 26.