WO1999023692A1

WO1999023692A1 - Aligner and exposure method

Info

Publication number: WO1999023692A1
Application number: PCT/JP1998/004843
Authority: WO
Inventors: Tetsuo Taniguchi
Original assignee: Nikon Corporation
Priority date: 1997-10-31
Filing date: 1998-10-26
Publication date: 1999-05-14
Also published as: JP4210871B2; JPH11135400A; AU9648198A

Abstract

A wafer is put on a wafer stage which is placed on a surface plate transferably in an X-direction and a Y-direction. The pattern image of a reticle is exposed in an exposure region on the wafer and the reticle and the wafer are scanned in the Y-direction to perform exposure. A measurement stage is placed on the surface plate transferably in the X-direction and the Y-direction independently of the wafer stage. A space image detection system which includes a dose monitor, an illuminance unevenness sensor and a measurement plate in which a slit is formed is set up on the measurement stage. As the wafer stage may have only minimum functions necessary for exposure, the size and weight of the wafer stage can be reduced. With this constitution, the size of a stage for the alignment of a reticle or a wafer can be reduced while the function of measuring the state of an exposing light or image forming characteristics is maintained.

Description

Specification

Exposure apparatus and exposure method

The present invention relates to an exposure apparatus used for transferring a mask pattern onto a photosensitive substrate during a lithographic process for producing, for example, a semiconductor device, a liquid crystal display device, or a thin-film magnetic head. The exposure method is particularly suitable for use in an exposure apparatus provided with a measuring device g for measuring the state of an exposure beam, an imaging characteristic, and the like.

Background art

In manufacturing semiconductor devices, etc., in a process of transferring a reticle pattern as a mask under a predetermined exposure light onto a wafer (or a glass plate or the like) coated with a resist through a projection optical system, In the past, a batch exposure type projection exposure apparatus (stepper) was often used. Recently, in order to transfer the pattern of a large-sized rice reticle with high precision without increasing the size of the projection optical system, the 'and' scan step in which exposure is performed by synchronously scanning the reticle and wafer with respect to the projection optical system Attention is also focused on scanning exposure type projection exposure apparatuses (scanning exposure apparatuses).

In these exposure apparatuses, it is necessary to always perform exposure with an appropriate exposure amount and high image forming characteristics, so that a reticle stage for positioning the reticle or a wafer stage for positioning the wafer is required. There is provided a measuring device for measuring the state such as the illuminance of the exposure light and the imaging characteristics such as the projection magnification. For example, the measurement device provided on the wafer stage includes a radiation dose monitor for measuring the incident energy of the exposure light to the projection optical system, and the position of the projected image. There is an aerial image detection system for measuring contrast, etc. On the other hand, as a measuring device provided on the reticle stage, for example, there is a reference plate on which an index mark used for measuring the imaging characteristics of the projection optical system is formed.

In the conventional exposure apparatus as described above, the exposure amount is optimized by using a measurement apparatus provided on a reticle stage or a wafer stage, and high imaging characteristics are maintained. On the other hand, recent exposure apparatuses are also required to increase the throughput (productivity) of the exposure step when manufacturing semiconductor elements and the like. In order to improve throughput, in addition to increasing the exposure energy per unit time, the stage drive speed is increased. For molds, there is a method to shorten the time of stepping and the time of scanning exposure.

In order to improve the driving speed of the stage in this way, when the stage system has the same size, a driving motor with a larger output may be used, and conversely, a driving motor with the same output as the conventional one can reduce the driving speed. To improve it, it is necessary to reduce the size of the stage system and make it more suspicious. However, if a drive motor with a larger output is used as in the former case, the amount of heat generated from the drive motor increases. Such an increased amount of heat may cause delicate thermal deformation of the stage system, so that the high positioning accuracy required for the exposure apparatus may not be obtained. Therefore, in order to prevent the deterioration of positioning accuracy and increase the driving speed, it is desirable to make the stage system as small and light as possible as in the latter case.

In particular, in scanning exposure type exposure equipment, the scanning exposure time is shortened due to the improvement of the driving speed, and the scanning exposure time is reduced. In addition to greatly improving the size of the stage, the downsizing of the stage system also improves the synchronization accuracy between the reticle and the wafer, and has the major advantages of improving imaging performance and overlay accuracy. However, if various measuring devices are provided on the reticle stage or wafer stage as in the past, the stage must be small. It is difficult to type.

Furthermore, if the reticle stage or wafer stage is equipped with a measuring device to measure the state of the exposure light or the imaging characteristics, the measuring device usually includes a heat source such as an amplifier and However, during measurement, the temperature of the measuring device gradually increases due to exposure light exposure. As a result, the reticle stage or wafer stage may be slightly thermally deformed, and the positioning accuracy and the overlay accuracy may be degraded. At present, the deterioration of positioning accuracy and the like due to the temperature rise of the measuring device is slight, but in the future, as the circuit pattern of semiconductor elements etc. becomes finer, it is necessary to suppress the influence of the temperature rise of the measuring device. Expected to increase.

In view of the above, the present invention provides an exposure apparatus capable of miniaturizing a stage for positioning a reticle or a wafer while maintaining a state of exposure light or a function of measuring an imaging characteristic. This is the first purpose.

Further, the present invention provides a light exposure device which includes a measurement device for measuring the state of exposure light or an imaging characteristic, and which can reduce an adverse effect of a rise in temperature when measuring using the measurement device. Is the second purpose.

In view of the above, the present invention provides an exposure method capable of miniaturizing a stage for positioning a reticle or a wafer while maintaining a state of exposure light or a function of measuring imaging characteristics. The third purpose.

Further, the present invention provides a light exposure method that includes a measurement device for measuring the state of exposure light or an imaging characteristic and that can reduce an adverse effect of a rise in temperature when performing measurement using the measurement device. The fourth purpose. Disclosure of the invention

A first exposure apparatus according to the present invention is an exposure apparatus that transfers a pattern formed on a mask onto a substrate by using an exposure beam. A first stage that moves a predetermined area while holding one of them, a second stage that is independent of the first stage, and measures the state of the exposure beam that is attached to the second stage And a measuring device.

According to the present invention, the size of the first stage is minimized by providing only the minimum function necessary for the exposure to the first stage used for the original exposure. The stage can be made smaller and lighter. On the other hand, since the measuring device that is not directly required for exposure and measures the state of the illuminance of the exposure beam and the like is mounted on another second stage, the state of the exposure beam can also be measured.

In this case, an example of the measuring device is a photoelectric sensor that measures the entire power of the exposure beam, an uneven illuminance sensor that measures the illuminance distribution of the exposure beam, or the like. Further, the second stage is, for example, arranged so as to be movable independently of the first stage, for example, on a moving surface of the first stage. At this time, by arranging the second stage in place of the first stage, the state of the exposure beam in the vicinity of the surface where the mask or the substrate is actually arranged can be measured.

Further, it is desirable to have a control device for moving the first stage between a position where the exposure beam is irradiated and a position where the exposure beam is not irradiated. At this time, at the time of measurement, the first stage is retracted from the irradiation position of the exposure beam.

Further, it is desirable to have a control device for moving the second stage between a position where the exposure beam is irradiated and a position where the exposure beam is not irradiated. Thus, at the time of measurement, the measurement device of the second stage moves to the irradiation position of the exposure beam.

In addition, when the first stage is at a position where the exposure beam is irradiated, control for positioning the second stage at a position where the exposure beam is not irradiated is performed. It is desirable to have a device. This allows the two stages to be used efficiently during exposure and measurement.

Next, a second exposure apparatus according to the present invention is an exposure apparatus that projects a pattern formed on a mask onto a substrate via a projection optical system. A first stage that moves through an area of the first stage, a second stage that is independent of the first stage, and a measurement that is arranged on the second stage and measures the imaging characteristics of the projection optical system And a device.

According to the present invention, it is possible to reduce the size and weight of the first stage by giving the first stage only the minimum functions necessary for exposure. On the other hand, since a measuring device that is not directly required for exposure and measures imaging characteristics such as distortion is mounted on another second stage, the imaging characteristics can also be measured. In this case, an example of the measuring device is a position sensor of a projected image, a measurement index mark, a measurement reference plane, or the like.

Further, the second stage is, for example, arranged so as to be movable independently of the first stage, for example, on a moving surface of the first stage. At this time, by arranging the second stage in place of the first stage, the imaging characteristics on the surface where the substrate is actually arranged can be measured.

The first stage holds the substrate, and moves the first stage between a position within the exposure area by the projection optical system and a predetermined position outside the exposure area. It is desirable to have a control device. At this time, the first stage is retracted from the exposure area during measurement.

Similarly, it is desirable to have a control device for moving the second stage between a position within the exposure area by the projection optical system and a predetermined position outside the exposure area. At this time, at the time of measurement, the measurement device of the second stage moves to the exposure area. Next, in a third exposure apparatus of the present invention, in the exposure apparatus for transferring a pattern formed on a mask onto a substrate using an exposure beam, a measurement apparatus for measuring a state of the exposure beam is provided. A stage, and a cooling device provided on the stage to cool the measuring device.

According to the present invention, even when the temperature of the measurement device rises when measuring the illuminance of the exposure beam using the measurement device, the measurement device is cooled by the cooling device. The fourth exposure apparatus of the present invention projects the pattern formed on the mask onto the substrate via the projection optical system. It has a stage on which a measuring device for measuring characteristics is arranged, and a cooling device provided on this stage for cooling the measuring device.

According to the present invention, even when the temperature of the measurement device rises when measuring the imaging characteristics using the measurement device, the measurement device is cooled by the cooling device. impact of beyond ₃

Next, a fifth exposure apparatus of the present invention is an exposure apparatus for transferring a pattern formed on a mask onto a substrate by using an exposure beam, wherein one of the mask and the substrate is held. A first stage that moves through a predetermined area, a second stage equipped with a measuring device that measures the state of the exposure beam, and an interposed space between the first stage and the second stage And a heat insulating member that blocks heat conducted from the second stage.

According to the present invention, even if the measuring device includes a heat source, or the temperature of the measuring device increases when measuring the illumination of the exposure beam using the measuring device, Heat conduction is hindered by the heat insulating member, and the exposed area is not affected by the heat source or temperature rise.

In this case, one example of the heat insulating member is a solid material with low thermal conductivity or temperature control. Gas. Air-conditioned gas is used as the temperature-adjusted gas.

Next, a sixth exposure apparatus of the present invention is directed to an exposure apparatus that projects a pattern formed on a mask onto a substrate via a projection optical system, wherein the first exposure apparatus holds the substrate and moves in a predetermined area. A second stage equipped with a measuring device for measuring the imaging characteristics of the projection optical system, and a second stage disposed between the first stage and the second stage. And a heat insulation section that blocks the heat conducted from the stage.

According to the present invention, even when the measurement device increases in temperature when measuring the imaging characteristics using the measurement device, or the measurement device includes a heat source, Therefore, the heat conduction is hindered, so that the exposed portion is not affected by the temperature rise or the like.

Also in this case, an example of the heat insulating member is a solid material having low thermal conductivity or a temperature-controlled gas.

A first exposure method according to the present invention is an exposure method for transferring a pattern formed on a mask onto a substrate using an exposure beam, wherein the first stage holds one of the mask and the substrate. And moving a predetermined area, and a step of measuring the state of the exposure beam by a measuring device attached to a second stage independent of the first stage.

According to the present invention, the size of the first stage is minimized by providing only the minimum function necessary for the exposure to the first stage used for the original exposure. The stage can be made smaller and lighter. On the other hand, since the measuring device that is not directly required for exposure and measures the state of the illuminance of the exposure beam and the like is mounted on another second stage, the state of the exposure beam can be measured.

In this case, an example of the measuring device is a light that measures the overall power of the exposure beam. An electric sensor or an uneven illuminance sensor that measures the illuminance distribution of the exposure beam. Further, the second stage is, for example, arranged so as to be movable independently of the first stage, for example, on a moving surface of the first stage. At this time, by arranging the second stage in place of the first stage, the state of the exposure beam in the vicinity of the surface where the mask or the substrate is actually arranged can be measured.

Further, it is desirable that the movement of the first stage is performed depending on a position where the exposure beam is irradiated and a position where the exposure beam is not irradiated. At this time, at the time of measurement, the first stage is retracted from the irradiation position of the exposure beam.

It is also desirable that the second stage further includes a step of moving between a position where the exposure beam is irradiated and a position where the exposure beam is not irradiated. Thus, at the time of measurement, the measurement device of the second stage moves to the irradiation position of the exposure beam.

Further, it is preferable that the method further includes a step of positioning the second stage at a position where the exposure beam is not irradiated when the first stage is at the position irradiated with the exposure beam. This allows the two stages to be used efficiently during exposure and measurement.

Next, in a second exposure method according to the present invention, in the exposure method for projecting a pattern formed on a mask onto a substrate via a projection optical system, the first stage may include any one of the mask and the substrate. A step of moving a predetermined area while holding one of them, and a step of measuring an imaging characteristic of the projection optical system by a measuring device arranged on a second stage independent of the first stage. Including.

According to the present invention, it is possible to reduce the size and weight of the first stage by providing only the minimum functions necessary for the exposure to the first stage used for the original exposure. become. On the other hand, there is no need for direct exposure and distortion Since the measuring device for measuring the imaging characteristics such as is mounted on another second stage, the imaging characteristics can also be measured.

In this case, an example of the measuring device is a position sensor of a projected image, a measurement index mark, a measurement reference plane, or the like.

The first stage holds the substrate, and the movement of the first stage moves between a position within the exposure area by the projection optical system and a predetermined position outside the exposure area. It is desirable that this be done. At this time, the first stage is retracted from the exposure area during measurement.

Similarly, it is preferable that the second stage further includes a step of moving the position between the position within the exposure area by the projection optical system and a predetermined position outside the exposure area. At this time, at the time of measurement, the measurement device of the second stage moves to the exposure area.

Next, in a third exposure method of the present invention, in the exposure method in which a pattern formed on a mask is transferred onto a substrate using an exposure beam, a measuring device disposed on a stage is provided with a state of the exposure beam. And a step of cooling the measuring device by a cooling device provided in the stage.

According to the present invention, even when the temperature of the measurement device rises when measuring the illuminance of the exposure beam using the measurement device, the measurement device is cooled by the cooling device. Is not affected by the temperature rise.

Next, a fourth exposure method of the present invention is directed to an exposure method for projecting a pattern formed on a mask onto a substrate via a projection optical system. The apparatus includes a step of measuring an imaging characteristic of the projection optical system, and a step of cooling the measurement apparatus by a cooling device provided on the stage. According to the present invention, even when the temperature of the measurement device rises when measuring the imaging characteristics using the measurement device, the measurement device is cooled by the cooling device. Is not affected.

Next, in a fifth exposure method according to the present invention, in the exposure method for transferring a pattern formed on a mask onto a substrate using an exposure beam, the first stage may include any one of the mask and the substrate. Moving a predetermined area while holding one of them, a measuring device attached to a second stage measures a state of the exposure beam, and a step of measuring the state of the first stage and the second stage. Cutting off heat conducted from the second stage by a heat insulating member arranged between the stage and the stage.

According to the present invention, even when the measuring device includes a heat source, or when the temperature of the measuring device rises when measuring the illuminance or the like of the exposure beam using the measuring device, the heat insulating member is provided. As a result, heat conduction is hindered, and the exposed portion is not affected by the heat source or temperature rise.

In this case, an example of the heat insulating member is a solid material having low thermal conductivity or a gas whose temperature is adjusted. Air-conditioned gas is used as the temperature-adjusted gas.

Next, in a sixth exposure method according to the present invention, in the exposure method for projecting a pattern formed on a mask onto a substrate via a projection optical system, the first stage holds the substrate and performs a predetermined operation. Moving the area of the projection optical system, measuring the imaging characteristics of the projection optical system with the measuring device mounted on the second stage, and connecting the first stage with the second stage. the arrangement adiabatic member between, is intended to include a step of interrupting the heat conducted from the second stages _c According to the present invention, even when the measurement device rises in temperature when measuring the imaging characteristics using the measurement device, or even when the measurement device includes a heat source, the heat insulating member is used. Since heat conduction is hindered, the exposed portion is not affected by the temperature rise or the like.

Also in this case, an example of the heat insulating member is a solid material having low thermal conductivity or a temperature-controlled gas. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic configuration diagram showing a projection exposure apparatus according to a first embodiment of the present invention.

FIG. 2 is a plan view showing reticle stage R ST and measurement stage 5 of FIG.

FIG. 3 is a plan view showing the wafer stage WST and the measurement stage 14 of FIG.

FIG. 4 is a plan view for describing a case where the state of exposure light or the like is measured using the measurement stage 14 in the first embodiment of the present invention.

FIG. 5 is a plan view showing a wafer stage and a measurement stage of a projection exposure apparatus according to a second embodiment of the present invention.

FIG. 6 is a front view showing a wafer stage and a measurement stage of a projection exposure apparatus according to a second embodiment of the present invention.

FIG. 7 is a schematic configuration diagram with a part cut away showing a projection exposure apparatus according to a third embodiment of the present invention.

FIG. 8 is a plan view showing a wafer stage of the projection exposure apparatus of FIG. FIG. 9 is a plan view showing a wafer stage of a projection exposure apparatus according to a fourth embodiment of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 to 4.

Fig. 1 shows the projection exposure apparatus of the step 'and' scan method used in this example. In Fig. 1, the exposure light source, beam shaping optical system, fly-eye lens for uniformizing the illuminance distribution, and light intensity The exposure light IL emitted from the illumination system 1 including the monitor, the variable aperture stop, the field stop, and the relay lens system passes through the mirror 1 and the condenser lens 3, and the pattern surface of the reticle R (lower surface). This illuminates the slit-shaped illumination area. The exposure light IL is excimer laser light such as KrF (wavelength 248 nm) or ArF (wavelength 193 nm), harmonics of a YAG laser, or i-line of a mercury lamp. (Wavelength 365 nm) can be used. By switching the variable aperture stop in the illumination system 1, it is possible to select a desired illumination method from among ordinary illumination, annular illumination, so-called deformed illumination, and illumination with a small coherence factor (σ value). It is configured. When the exposure light source is a laser light source, the light emission timing and the like are controlled via a laser power supply (not shown) by a main control system 10 that controls the overall operation of the apparatus.

The image of the pattern in the illuminated area 9 (see Fig. 2) of the reticle R by the exposure light IL is projected through the projection optical system PL at a projection magnification of | 3 (] 3 is 1 × 4 or 1 × 5 , Etc.) and projected onto a slit-like exposed area 12 on the wafer W coated with the photo resist. Hereinafter, the Ζ axis is taken in parallel with the optical axis Α の of the projection optical system PL, and the non-scanning direction (that is, the The X axis is taken along the direction perpendicular to the plane of FIG. 1 and the Υ axis is taken along the scanning direction (that is, the direction parallel to the plane of FIG. 1). First, an off-axis system for wafer W alignment and an image processing system An alignment sensor 16 is provided adjacent to the projection optical system PL, and a detection signal of the alignment sensor 16 is supplied to an alignment processing system in the main control system 10. The alignment sensor 16 is used to detect the position of a positioning mark (wafer mark) formed on the wafer W. The distance (baseline amount) between the detection center of the alignment sensor 16 and the center of the projected image of the reticle R by the projection optical system PL is obtained with high precision in advance and stored in the alignment processing system in the main control system 10. The shot area of the wafer W and the projected image of the reticle R are superimposed on the basis of the detection result of the alignment sensor 16 and the baseline amount thereof with high accuracy. Although not shown, a reticle alignment microscope for detecting an alignment mark on the reticle R is disposed above the reticle R.

Next, reticle R is held on reticle stage RST by vacuum suction, and reticle stage RST is placed on two guides 4 A and 4 B arranged in parallel in the Y direction via an air bearing. It is mounted movably in the Y direction. Further, in this example, the measurement stage 5 is mounted on the guides 4A and 4B so as to be movable in the Y direction via an air bearing independently of the reticle stage RST.

FIG. 2 is a plan view showing the reticle stage RST and the measurement stage 5, which are not shown along the guides 4A and 4B extending in the Y direction (scanning direction). A reticle stage RST and a measurement stage 5 are mounted so as to be driven in the Y direction by a linear motor or the like. The lengths of the guides 4 A and 4 B are set to be at least longer than the moving stroke of the reticle stage RST at the time of the running exposure by at least the length of the measuring stage 5. The reticle stage RST is configured by combining a coarse movement stage that moves in the Y direction and a fine movement stage that allows fine adjustment of the two-dimensional position on the coarse movement stage. ing.

A reference plate 6 made of a glass plate elongated in the X direction is fixed on the measurement stage 5, and a plurality of index marks IM for measuring the imaging characteristics of the projection optical system PL are formed on the reference plate 6 in a predetermined arrangement. Have been. The reference plate 6 is large enough to cover the slit-shaped illumination area 9 of the exposure light for the reticle R, more precisely, the field of view of the projection optical system PL on the reticle R side. By using the reference plate 6, there is no need to prepare a dedicated reticle for measuring the imaging characteristics, and it is not necessary to replace the reticle R for actual exposure with the dedicated reticle. The image characteristics can be measured with high frequency, and it can accurately follow the temporal change of the projection optical system PL. Thus, in this example, the measurement stage 5 for the reference plate 6 is provided independently, and no measurement member other than the reticle R is mounted on the original reticle stage R ST. In other words, the reticle stage R ST need only have the minimum scanning and positioning functions required for scanning exposure, and thus the reticle stage R ST has been reduced in size and weight. Therefore, the reticle stage RST can be scanned at higher speed, so that the throughput of the exposure step is improved. In particular, in the case of reduced projection, the running speed of the reticle stage RST is Ζ β times the running speed of the wafer stage (for example, 4 times, 5 times, etc.), and the upper limit of the scanning speed is almost the same in the reticle stage. In some cases, the throughput is greatly improved in this example.

In addition, a laser beam is emitted from a laser interferometer 7 設置 installed in the + Υ direction to the guides 4 Α and 4 に to a movable mirror on the + Υ direction side of the reticle stage RS 、, The laser beam is irradiated from the two-axis laser interferometers 7 X 1 and 7 X 2 installed in the Χ direction to the moving mirror on the + X direction side of the reticle stage RS 、, and the laser interferometers 7 Υ and 7 The X coordinate, Χ coordinate, and rotation angle of reticle stage RST are measured by X 1, 7 7 2, and the measured values are supplied to main control system 10 in FIG. 10 controls the speed and position of the reticle stage RST via a linear motor or the like based on the measured value. In addition, a laser beam is emitted from a laser interferometer 8Y installed in one Y direction to the guides 4A and 4B to a movable mirror on one side in the Y direction of the measurement stage 5, and the laser beam is irradiated. The Y coordinate of the measurement stage 5 measured by the interferometer 8 Y is supplied to the main control system 10. The optical axes of the laser interferometers 7 Y and 8 Y on the Y axis respectively pass through the center of the illumination area 9, that is, the optical axis AX of the projection optical system PL along the Y direction. And 8Y constantly measure the positions of the reticle stage RST and the measurement stage 5 in the scanning direction, respectively. When measuring the imaging characteristics, the reticle stage RST is retracted in the + Y direction, and the measurement stage 5 is moved in the Y direction so that the reference plate 6 covers the illumination area 9. The laser beams from X 1, 7 X 2 deviate from the side surface of reticle stage RST and irradiate the movable mirror on the + X direction side surface of measurement stage 5. At this time, the main control system 10 controls the position of the measurement stage 5 with high precision via a reversing motor, etc., based on the measured values obtained from the laser interferometers 8Y and 7X1, 7X2. . In this case, if it is desired to align the reference plate 6 with respect to the illumination area 9 with higher accuracy, an alignment mark is formed on the reference plate 6 and the position of this mark is determined by a reticle alignment. What is necessary is just to detect using a microscope.

On the other hand, during measurement, the position of reticle stage RST in the non-scanning direction is not measured. However, if reticle stage RST reaches below illumination area 9 for exposure, laser interferometers 7 X 1 and 7 X 2 From the reticle stage RST. Since the final alignment is performed using a reticle alignment microscope, there is no inconvenience that the laser beams from the laser interferometers 7X1 and 7X2 are interrupted. Wafer stage W via the wafer holder shown The wafer stage WST is held on the ST, and is mounted on the surface plate 13 via an air bearing so as to be movable in the X and Υ directions. The wafer stage WS also incorporates a focus / leveling mechanism for controlling the position (focus position) of the wafer W in the vertical direction and the tilt angle. In addition, a measurement stage 14 equipped with various measurement devices is mounted on the surface plate 13 separately from the wafer stage WS に through an air bearing so as to be movable in the X and Υ directions. ing. The stage 14 for measurement also has a built-in mechanism to control the focus position on its upper surface.

FIG. 3 is a plan view showing the wafer stage WST and the measurement stage 14. In FIG. 3, for example, a coil row is embedded in a predetermined arrangement inside the surface of the surface plate 13. On the bottom surface of the wafer stage WST and the bottom surface of the measurement stage 14, a magnet row is embedded together with a yoke, and the coil row and the corresponding magnet row constitute a planar motor, respectively. Therefore, the positions of the wafer stage WST and the measurement stage 14 in the X and Y directions and the rotation angle are controlled independently of each other. The flat motor is disclosed in more detail in, for example, Japanese Patent Application Laid-Open No. 8-51756.

The wafer stage WST of this example has only the minimum functions required for exposure. In other words, the wafer stage WST has a focus and leveling mechanism, and a wafer holder (bottom side of wafer W) that holds the wafer W by suction and a position measurement of the wafer stage WST on the wafer stage WST. The reference mark plate 17 and the two members are fixed. A reference mark (not shown) serving as a position reference in the X direction and the Y direction is formed on the reference mark plate 17, and the position of the reference mark is detected by the alignment sensor 16. , the wafer stage WST ₂ the positional relationship relative to the projection image, for example, reticle R (the wafer W) is discovered Further, the surface of measurement stage 14 is set at substantially the same height as the surface of wafer W on wafer stage WST. The measurement stage 14 has an irradiation amount monitor 18 composed of a photoelectric sensor for measuring the total energy per unit time (incident energy) of the exposure light that has passed through the projection optical system PL. System Irradiance unevenness sensor 19 consisting of photoelectric sensors for measuring the illuminance distribution in the slit-like exposure area 12 by the PL, and slits 21 X and 21 Y for measuring the imaging characteristics were measured. Plate 20 is fixed. On the bottom side of the X-axis slit 21 X and the Y-axis slit 21 Y of the measurement plate 20, a condenser lens and a photoelectric sensor are arranged, respectively, from the measurement plate 20 and the photoelectric sensor. An aerial image detection system is configured. Note that instead of the slits 2IX and 21Y, a rectangular opening edge may be used. The light receiving surface of the irradiation amount monitor 18 is formed to have a size to cover the exposure area 12, and the light receiving portion of the uneven illuminance sensor 19 has a pinhole shape. The detection signal of the unevenness sensor 19 is supplied to the main control system 10 shown in FIG.

The detection signal of the photoelectric sensor at the bottom of the measurement plate 20 is supplied to the imaging characteristic calculation system 11 in FIG. In this case, when measuring the imaging characteristics of the projection optical system PL, the reference plate 6 on the measurement stage 5 on the reticle side in FIG. 2 is moved to the illumination area 9 and the index mark IM formed on the reference plate 6 is measured. Is projected on the wafer stage side, and the images are scanned in the X and Y directions by slits 21X and 21Y on the measurement plate 20, respectively, and the detection signal from the photoelectric sensor at the bottom is scanned. Captured by the imaging characteristics calculation system 1 1. The imaging characteristic calculation system 11 processes the detection signal to detect the position, contrast, etc. of the image of the index mark IM, and from this detection result, the curvature of field of the projected image, distortion, and best focus. An image forming characteristic such as one spot position is obtained and output to the main control system 10. Further, although not shown, a mechanism for driving a predetermined lens in the projection optical system PL to correct an imaging characteristic such as a predetermined disposition is also provided. The main control system 10 is configured to correct the imaging characteristics of the projection optical system PL via this correction mechanism.

In FIG. 3, sensors such as an irradiation amount monitor 18 provided on the measurement stage 14, an uneven illuminance sensor 19, and a photoelectric sensor at the bottom of the measurement plate 20 are all provided with a heat source such as an amplifier. , And power and communication signal cables are connected. Therefore, if those sensors are mounted on the wafer stage WST for exposure, the positioning accuracy and the like may be deteriorated due to the heat source and the tension of the signal cable attached to the sensors. In addition, thermal energy due to exposure light exposure during measurement of imaging characteristics and the like may cause deterioration of positioning accuracy and the like. On the other hand, in this example, since those sensors are provided on the measurement stage 14 separated from the exposure wafer stage WST, the wafer stage WST can be reduced in size and weight, and the measurement stage 14 There is an advantage that a decrease in positioning accuracy due to a heat source of the sensor or heat energy of exposure light during measurement can be prevented. The downsizing of the wafer stage WST improves the moving speed and controllability of the wafer stage WST, increasing the throughput of the exposure process and improving the positioning accuracy, etc. A laser beam is irradiated from the laser interferometer 15 Y installed in the + Y direction to the moving mirror on the + Y direction side of the wafer stage WST, and the two-axis laser interference installed in the 1X direction A laser beam is radiated from a total of 15X1, 15X2 to a moving mirror on one side in the X direction of the wafer stage WS T, and the wafer interferometers 15Y, 15X1, 15X2 are used to illuminate the wafer stage WS. The X coordinate, Y coordinate, and rotation angle of T are measured, and the measured values are supplied to the main control system 10 shown in FIG. 1, and the main control system 10 sends the wafer stage through a planar motor based on the measured values. Control the speed and position of WST. When measuring the incident energy of the exposure light and the like, the position measuring laser beam is applied to the movable mirror of the measuring stage 14.

Fig. 4 shows the wafer stage WST and the measurement of the incident energy of the exposure light, etc. An example of the arrangement of the measurement stage 14 is shown in FIG. 4. The wafer stage WST is retracted away from the exposure region 12 as shown in FIG. When the measurement stage 14 is moved upward, the laser beams from the laser interferometers 15Y, 15X1, and 15X2 move off the side of the wafer stage WS WS and the measurement stage 14 Irradiates the moving mirror on the side of the camera. At this time, based on the measurement ^ S obtained from the laser interferometers 15Υ and 15X1, 15X2, the main control system 10 moves the position of the measurement stage 14 via the plane motor. Control with high precision. It should be noted that the position of the wafer stage WS 1 and the measurement stage 14 can be roughly controlled by driving the planar motor in an open loop. Therefore, when the laser beam is not irradiated, the main control system 10 The position of the wafer stage WST and the position of the measurement stage 14 are driven by an open loop method using a planar motor. However, in addition to the laser interferometers 15Y, 15X1, 15X2, a linear encoder, etc., for detecting the positions of the wafer stage WST and the measurement stage 14 with predetermined accuracy is provided. In the state where the laser beam is not irradiated, position measurement may be performed using such a linear encoder or the like.

Referring back to FIG. 1, although not shown, a slit image is obliquely projected onto a plurality of measurement points on the surface of the wafer W on the side surface of the projection optical system PL, and is re-imaged by the reflected light. An oblique incidence type focus position detection system (AF sensor) that detects the focus position of the corresponding measurement point based on the amount of lateral shift of the slit image is provided. Based on the detection result of the focus position detection system, the surface of the wafer W during the scanning exposure is focused on the image plane of the projection optical system P. Although not shown in FIG. 3, a reference member having a reference surface for the focal position detection system is also mounted on the measurement stage 14.

Next, the operation of the projection exposure apparatus of this embodiment will be described. First, the incident light amount of the exposure light IL to the projection optical system PL using the measurement stage 14 of the wafer stage 侧 Is measured. In this case, in order to measure the amount of incident light with the reticle R loaded, in FIG. 1, the reticle R for exposure is loaded on the reticle stage RST, and the reticle R is placed on the illumination area of the exposure light IL. Go to Thereafter, as shown in FIG. 4, the wafer stage WST is retracted on the surface plate 13 in, for example, the + Y direction, and the measurement stage 14 moves toward the exposure area 12 by the projection optical system PL. . Thereafter, the measurement stage 14 stops at a position where the light receiving surface of the irradiation amount monitor 18 on the measurement stage 14 covers the exposure area 12, and in this state, the exposure light IL passes through the irradiation amount monitor 18. The light quantity is measured.

The main control system 10 supplies the measured light amount to the imaging characteristic calculation system 11. At this time, for example, a measurement value obtained by detecting a light beam obtained by branching from the exposure light IL in the illumination system 1 is also supplied to the imaging characteristic calculation system 11. Based on the two measured values, a coefficient for indirectly calculating the amount of light incident on the projection optical system PL from the amount of light monitored in the illumination system 1 is calculated and stored. During this time, the wafer W is loaded on the wafer stage WST. Then, as shown in FIG. 3, the measurement stage 14 is retracted away from the exposure area 12 so that the center of the wafer W on the wafer stage WST is aligned with the optical axis AX (exposure area) of the projection optical system PL. The wafer stage WST is moved so as to be located near (center of 12). When the wafer stage WST is retracted, as shown in Fig. 4, the laser beams from the laser interferometers 15Y, 15X1, and 15X2 are not irradiated. Position control is performed by driving in an open loop system.

After that, the measurement stage 14 is retracted from the exposure area 12 and the wafer stage WST is irradiated with laser beams from the laser interferometers 15Y, 15X1, and 15X2. Then, the position of the wafer stage WST will be controlled based on the measurements of those laser interferometers- Using a reticle alignment microscope (not shown), the amount of misalignment between a predetermined alignment mark on reticle R and a predetermined reference mark on reference mark member 17 in FIG. 3 is set to a predetermined target value. Then, reticle R is aligned by driving reticle stage RST. At about the same time, the position of another fiducial mark on the fiducial mark member 17 is detected by the alignment sensor 16 in FIG. 1, whereby the positional relationship with respect to the projected image of the reticle R of the wafer stage WST is obtained. (Baseline amount) is accurately detected.

Next, the array coordinates of each shot area of the wafer W are detected by detecting the position of a wafer mark attached to a predetermined shot area (sample shot) on the wafer W via the alignment sensor 16. Desired. After that, based on the arrangement coordinates and the known baseline amount of the alignment sensor 16, scanning exposure is performed while aligning the shot area of the wafer W to be exposed with the pattern image of the reticle R. Is performed.

At the time of scanning exposure, in FIG. 1, a reticle R is scanned at a speed VR in the + Y direction (or one Y direction) via a reticle stage RST with respect to an illumination area 9 (see FIG. 2) of the exposure light IL. In synchronism with this, the wafer W is scanned in the -X direction (or + X direction) at a speed of; 3-VR (β is a projection magnification) with respect to the exposure area 12 via the ゥヱ Hast WST. . The opposite of the scanning direction is due to the projection optical system PL projecting a reverse image. When the exposure of one shot area is completed, the next shot area moves to the run start position by the stepping of the wafer stage WST. Thereafter, the exposure to each shot area is performed by the step-and-scan method. Are sequentially performed. During this scanning exposure, as shown in FIGS. 2 and 3, the measurement stage 14 on the wafer stage side and the measurement stage 5 on the reticle stage side are respectively retracted outside the exposure area. .

Also, during the exposure, for example, the light amount of the luminous flux branched from the exposure light IL in the illumination system 1 Is constantly measured and supplied to the imaging characteristic calculation system 11. The imaging characteristic calculation system 11 calculates the exposure amount incident on the projection optical system PL based on the measured value of the supplied light amount and the coefficient obtained in advance. The amount of light IL is calculated, the amount of change in the imaging characteristics (projection magnification, distortion, etc.) of the projection optical system PL caused by the absorption of the exposure light IL is calculated, and the calculation result is supplied to the main control system 10. I do. The main control system 10 corrects the image forming characteristics by, for example, driving a predetermined lens in the projection optical system PL. The above is the normal exposure, but when measuring the state of the projection exposure apparatus of the present example for maintenance or the like, the measurement stage 14 is moved to the exposure area 12 to perform the measurement. For example, when measuring the illuminance uniformity in the exposure area 12, after removing the reticle R from the reticle stage RST, in FIG. 4, the uneven illuminance sensor 19 is moved in the X direction and the Y direction in the exposure area 12. The illuminance distribution is measured while moving slightly. At this time, if it is necessary to more accurately determine the position of the measurement stage 14, a reference mark member equivalent to the reference mark member 17 is provided on the measurement stage 14 similarly to the wafer stage WST. Alternatively, the alignment sensor 16 may measure the position of the reference mark in the reference mark member.

Next, an operation of measuring the image formation measurement of the projection optical system PL using the measurement stage 5 of the reticle stage I and the measurement stage 14 on the wafer stage side will be described. In this case, in FIG. 2, the reticle stage R ST retracts in the + Y direction, and the reference plate 6 on the measurement stage 5 moves into the illumination area 9. At this time, the measurement stage 5 is also irradiated with laser beams from the laser interferometers 7 X 1 and 7 X 2 in the non-scanning direction, so that the laser interferometers 8 Y, 7 X 1 and 7 X The position of the measurement stage 5 can be positioned with high accuracy based on the measurement value of 2.

At this time, as described above, the images of the plurality of index marks I 投影 are projected on the wafer stage side through the projection optical system PL. In this state, in FIG. Driving, the index mark I with the slit on the measuring plate 20 The image of M is scanned in the X and Y directions, and the detection signal of the photoelectric sensor at the bottom of the measurement plate 20 is processed by the imaging characteristic calculation system 11 to obtain the position and contrast of those images. Can be Further, while changing the focus position of the measuring plate 20 by a predetermined amount, the positions of the images and the contrast are obtained. From these measurement results, the imaging characteristic calculation system 1] calculates the amount of variation in the imaging characteristics such as the best focus position, field curvature, and distortion (including a magnification error) of the projection image of the projection optical system PL. . This variation is supplied to the main control system 10. If the variation exceeds the allowable range, the main control system 10 corrects the imaging characteristics of the projection optical system PL. In the above embodiment, as shown in FIG. 3, wafer stage WST and measurement stage 14 are each driven by a flat motor on surface plate 13. However, a configuration in which the wafer stage WST and the measurement stage 14 are two-dimensionally driven by a combination of a one-dimensional motor is also possible.

Therefore, a second embodiment in which the wafer stage and the measurement stage are each driven by a mechanism combining a one-dimensional motor will be described with reference to FIGS. 5 and 6. Also in this example, the present invention is applied to a step-and-scan type projection exposure apparatus. In FIGS. 5 and 6, parts corresponding to FIGS. 1 and 3 are denoted by the same reference numerals. The detailed description is omitted.

FIG. 5 is a plan view showing the wafer stage side of the projection exposure apparatus of this example, and FIG. 6 is a front view thereof. In FIGS. 5 and 6, two X-axis linear guides 34 A and 34 B are installed on the upper surface of the surface plate 33 in parallel along the X direction, and the X-axis linear guides 34 A and 34 A are provided. An elongated Y-axis linear guide 32 is installed in the Y direction (running direction) to connect 34B. The Y-axis linear guide 32 is driven in the X direction along the X-axis linear guides 34 A and 34 B by a linear motor (not shown).

In addition, they can move in the Y direction along the Y-axis linear guides 32, and Independently, a wafer stage 31 and a measurement stage 35 are arranged independently, a wafer W is sucked and held on a wafer stage 31 via a wafer holder (not shown), and a dose is irradiated on the measurement stage 35. The monitor 18, the uneven illuminance sensor 19, and the measurement plate 20 are fixed, and a photoelectric sensor is incorporated at the bottom of the measurement plate 20. In this case, the bottom surfaces of the wafer stage 31 and the measurement stage 35 are placed on the surface plate 33 via air bearings, respectively, and the wafer stage 31 and the measurement stage 35 are independently independent. It is driven in the Y direction along the Y-axis linear guide 32 via the illustrated linear motor. That is, the wafer stage 31 and the measurement stage 35 are independently driven two-dimensionally along the Y-axis linear guide 32 and the X-axis linear guides 34A and 34B. Also in this example, the wafer stage 31 and the measurement stage were measured using a 4-axis laser interferometer similar to the laser interferometer 7Y, 7X1, 7X2, 8Y on the reticle stage side in FIG. The two-dimensional position of the stage 35 is measured, and the position and the driving speed of the wafer stage 31 and the measurement stage 35 are controlled based on the measurement result. Other configurations are the same as those of the first embodiment.

In this example, when measuring the irradiation energy of the exposure light or the imaging characteristics of the projection optical system, the wafer stage 31 is evacuated to a position away from the exposure area by the exposure light in one Y direction. The measurement stage 35 moves to the exposure area. On the other hand, at the time of exposure, the measurement stage 35 is evacuated to a position separated in the + Y direction from the exposure area by the exposure light. Then, the wafer stage 31 is stepped in the X and Y directions to move the exposure target shot area on the wafer W to the scanning start position for the exposure area, and then the wafer stage 31 is moved to the Y-axis linear guide. By moving at a constant speed in the Y direction along 32, scanning exposure is performed on the shot area.

According to this example as described above, the measurement stage is moved along the Y-axis linear guide 32. Reference numeral 35 is arranged independently of the wafer stage 31. With this configuration, it is not necessary to drive the measurement stage 35 in driving in the scanning direction (Y direction) where higher stage control accuracy is required, and the wafer stage 31 is reduced in size and weight. Therefore, the scanning speed can be improved, and the synchronization accuracy during scanning exposure has also been improved. On the other hand, the measurement stage 35 is simultaneously driven in the non-scanning direction (X direction), so that the load on the driving mechanism increases. However, in the non-scanning direction, much higher control accuracy is not required than in the scanning direction, so the effect of such an increase in load is small. Furthermore, since the measurement stage 35 as a heat source is separated from the wafer stage 31, a decrease in the positioning accuracy and the like of the wafer stage 31 is prevented.

In this example, as shown by a two-dot chain line in FIGS. 5 and 6, a second Y-axis linear guide 36 is arranged in parallel with the Y-axis linear guide 32 so as to be movable in the X direction. The measurement stage 35 may be arranged on the Y-axis linear guide 32 so as to be movable in the Y direction. Thereby, the control accuracy when driving wafer stage 31 in the X direction is also improved.

In the first embodiment, as shown in FIG. 2, the reticle stage RST and the measurement stage 5 are arranged along the same guides 4A and 4B. As shown on the wafer stage side in the figure, the reticle stage RS Τ and the measurement stage 5 may be independently movable two-dimensionally.

Further, in the above embodiment, one wafer stage WST, 31 on which wafer W is mounted is provided, but a plurality of wafer stages on which wafer W is mounted may be provided. In this case, it is also possible to use a method in which exposure is performed on one wafer stage and measurement for alignment or wafer replacement is performed on the other wafer stage. Similarly, a plurality of reticle stages on which the reticle R is mounted are provided on the reticle stage side, and these reticle stages are different. The reticle is placed on the wafer, and these reticles are sequentially exposed to the same shot area on the wafer by changing the exposure conditions (focus position, exposure amount, illumination conditions, etc.). The embodiment will be described with reference to FIGS. 7 and 8. In this example, a cooling device for cooling a measuring device provided on a wafer stage is provided. In FIGS. 7 and 8, parts corresponding to FIGS. 1 and 3 are denoted by the same reference numerals. The detailed description is omitted.

FIG. 7 shows the projection exposure apparatus of this example. In FIG. 7, a wafer W is arranged on the side of the exposure area 12 by the projection optical system PL, and the wafer W is placed on a wafer stage via a wafer holder (not shown). The wafer stage 41 is held on the surface plate 13 so as to be driven in, for example, the X and Y directions by a plane motor. Although not shown, a mechanism for controlling the focus position and the tilt angle of the wafer W is incorporated in the wafer stage 41. Further, the wafer stage 41 incorporates a mechanism for measuring the exposure light IL and the imaging characteristics so as to cover the wafer W. FIG. 8 is a plan view of the wafer stage 41 of FIG. 7. In FIG. 8, near the wafer W (wafer holder), the S quasi-mark member 17, the irradiation amount monitor 18, A measurement plate 20 on which an uneven illuminance sensor 19 and slits 21X and 21Y are formed is arranged. A concave portion 47 for installing a portable reference illuminometer is formed in the vicinity of the irradiation amount monitor 18 on the wafer stage 41, and the reference illuminometer is installed in the concave portion 47 to expose the exposure light. By measuring the incident energy of IL, it is possible to match the illuminance between different projection exposure apparatuses. Further, a reference member 46 having a reference plane serving as a reference for flatness or the like formed at one corner of the wafer stage 41 is also fixed. In this example, a cooling device for cooling the heat sources of these measurement mechanisms is provided.

That is, as shown in FIG. 7 with a part cut away, the slit 21 Y A condenser lens 42 and a photoelectric sensor 43 are arranged at the bottom of the device, and although not shown, an amplifier and the like are also connected to the photoelectric sensor 43. Therefore, a cooling pipe 44 is installed inside the wafer stage 41 so as to pass in the vicinity of the photoelectric sensor 43, and the cooling pipe 44 is connected to the external via a highly flexible pipe 45A. A refrigerant made of a low-temperature liquid is supplied from the cooling device, and the refrigerant that has passed through the pipe 45A is returned to the cooling device via a pipe 45B having great flexibility. In addition, the cooling pipe 44 is provided in the vicinity of the irradiation amount monitor 18 and the uneven illuminance sensor 19 shown in FIG. 8, and the bottom of the reference illuminometer concave portion 47, the reference mark member 17 and the reference member 46. Has also passed. In this example, since heat energy from a heat source such as an amplifier of these measuring devices is discharged through the refrigerant in the cooling pipe 44, the positioning accuracy of the wafer W is not deteriorated by the heat energy. . Also, when measuring the incident energy of the exposure light IL and the like, even when the exposure light IL is irradiated on the irradiation amount monitor 18 or the uneven illuminance sensor 19, the irradiation energy is transmitted through the refrigerant in the cooling pipe 44. Since it is discharged, the irradiation energy does not deteriorate the positioning accuracy of the wafer W.

In this example, the measuring device is cooled by using a liquid refrigerant.However, for example, air for air conditioning may be intensively blown to the vicinity of the measuring device to perform cooling. .

The piping configuration of the cooling pipes 4 and the arrangement of the measuring members (reference mark member 17, irradiation dose monitor 18, illuminance unevenness sensor 19, measuring plate 20, etc.) are as follows. However, various forms can be adopted as long as the members for measurement can be sufficiently cooled. Further, a plurality of cooling pipes 44 may be provided (or the cooling pipes 44 may be branched) to cool the respective measurement members in parallel.

Next, a fourth embodiment of the present invention will be described with reference to FIG. In this example, the arrangement area of the wafer (first stage) and the arrangement area of the measurement device on the wafer stage A heat insulating member is provided between the first and second regions (the second stage). In FIG. 9, portions corresponding to those in FIG. 8 are denoted by the same reference numerals, and detailed description thereof is omitted.

FIG. 9 shows a wafer stage 41 A driven in the X and Y directions on the surface plate in the same manner as the wafer stage 41 of FIG. 8. In FIG. 9, the upper part of the wafer stage 41 A is shown. Is divided into a measurement device installation area 41 Aa and other areas by a heat insulating plate 48 made of a material having a lower thermal conductivity than the wafer stage 41 A. Liquid in the case of using a metal or ceramics such as iron as the wafer stage 4 1 A, the resin as the insulating plate 4 8, glass, ₃ further as possible out the use of vacuum insulation pack, which is temperature control as a heat insulating plate 4 8 You can make it flow. Then, a wafer w is placed on the latter area via a wafer holder (not shown), and a reference mark member 17 serving as a position reference is installed, and the former measuring apparatus installation area 41 A a Inside, a reference mark member 17 A with a mark serving as a position reference is formed, a dose monitor 18, an uneven illuminance sensor 19, a reference member 46 having a reference plane, and a slit are formed. Measuring plate 20 is disposed. Further, a concave portion 47 for installing a reference illuminometer is formed on the measuring device installation area 41 Aa. In this example as well, measurement devices in the measurement device installation area 41 Aa are used when measuring the exposure light and the imaging characteristics, but the heat energy generated by the amplifiers and the like of these measurement devices is a heat insulating plate 4. 8 does not easily diffuse to the wafer W side, so that the positioning accuracy of the wafer W does not deteriorate. Similarly, there is an advantage that the irradiation energy given by the exposure light at the time of measurement is not easily diffused to the wafer W side by the heat insulating plate 48.

Note that, for example, as shown in FIG. 3, even in a configuration in which the wafer stage WST and the measurement stage 14 are separated, the air-conditioned air between the wafer stage WST and the measurement stage 14 is used as a heat insulating member. Can be considered. Also, on the reticle stage side, there is a difference between the area where the reticle is placed and the area where the measuring device is installed. Place a heat insulating member between them

In the above embodiments, the present invention is applied to a step-and-scan type projection exposure apparatus. However, the present invention can be applied to a batch exposure type projection exposure apparatus (stepper). The present invention can also be applied to a proximity type exposure apparatus that does not use a projection optical system. Further, the present invention may be used not only for an exposure apparatus, but also for an inspection apparatus using a stage for positioning a wafer or the like, a repair apparatus, or the like. As described above, the present invention is not limited to the above-described embodiment, and can take various configurations without departing from the gist of the present invention. Industrial applicability

According to the first or second exposure apparatus of the present invention, the first stage for moving the mask or the substrate is independently provided with the second stage including the measuring device. Therefore, there is an advantage that the stage for positioning the mask or substrate can be reduced in size and weight while maintaining the state of the exposure beam (exposure light) or the function of measuring the imaging characteristics of the projection optical system. . Therefore, the control performance of these stages can be improved, the throughput of the exposure process can be improved, and the heat source such as the photoelectric sensor or the amplifier that constitutes the measurement device can be separated from the exposure stage. Thus, the overlay accuracy and the like are improved. In particular, when the present invention is applied to a scanning exposure type exposure apparatus such as a step-and-scan method, the effect of the present invention is particularly large since the throughput is greatly improved by the improvement of the scanning speed.

In these cases, when the second stage is movably arranged independently of the first stage, the first stage can be quickly moved to the measurement area. When a control device is provided to move the first stage between the position where the exposure beam is irradiated (exposure area) and the position where the exposure beam is not irradiated (non-exposure area), the control device can quickly move the first stage during measurement. You can save the first stage. Further, when a control device is provided for moving the second stage between a position where the exposure beam is irradiated (exposure area) and a position where the exposure beam is not irradiated (non-exposure area), the control device can quickly move the second stage during the exposure. You can save the second stage.

Also, if the first stage is at the position where the exposure beam is irradiated, and if a control device for positioning the second stage at the position where the exposure beam is not irradiated is provided, the two stages are moved to the position where the exposure beam is not irradiated. They can be used efficiently.

According to the first or second exposure method of the present invention, the second stage having the measuring device is provided independently of the first stage for moving the mask or the substrate. There is an advantage that the stage for positioning the mask or the substrate can be reduced in size and weight while maintaining the state of the exposure beam (exposure light) or the function of measuring the imaging characteristics of the projection optical system. Therefore, the control performance of these stages can be improved, the throughput of the exposure process can be improved, and a heat source such as a photoelectric sensor or a pump constituting the measuring device is separated from the exposure stage. The overlay accuracy is improved. In particular, when the present invention is applied to a scanning exposure type exposure method such as a step 'and' scan method, the effect of the present invention is particularly large since the throughput is greatly improved by the improvement of the scanning speed.

In these cases, when the second stage is movably arranged independently of the first stage, the first stage can be quickly moved to the measurement area. When the first stage is moved between a position where the exposure beam is irradiated (exposure area) and a position where the exposure beam is not irradiated (non-exposure area), the first stage is quickly moved during measurement. You can evacuate.

When the second stage is moved between a position where the exposure beam is irradiated (exposure area) and a position where the exposure beam is not irradiated (non-exposure area), the second stage is quickly moved during the exposure. You can evacuate.

When the first stage is at the position where the exposure beam is irradiated, When positioning the stage in a position where the exposure beam is not irradiated, the two stages can be used efficiently.

Next, according to the third or fourth exposure apparatus of the present invention, or according to the third or fourth exposure method, since the cooling device for cooling the measurement device is provided, the state of the exposure beam, Alternatively, there is an advantage that the adverse effect of a rise in temperature when measuring the imaging characteristics of the projection optical system can be reduced, and positioning accuracy and overlay accuracy are improved.

According to the fifth or sixth exposure apparatus or the fifth or sixth exposure method of the present invention, since the heat insulating member is provided between the two stages, the state of the exposure beam In addition, there is an advantage that the adverse effect of a temperature rise when measuring the imaging characteristics of the projection optical system can be reduced, and positioning accuracy and overlay accuracy are improved.

Also, when the heat insulating member is a solid material having a low thermal conductivity, the two stages can be driven integrally, while when the heat insulating member is a gas whose temperature is adjusted, the first stage can be downsized. The effect is also obtained.

Claims

The scope of the claims

1. In an exposure apparatus that transfers a pattern formed on a mask onto a substrate using an exposure beam,

A first stage that moves a predetermined area while holding one of the mask and the substrate;

A second stage independent of the first stage;

A measuring device attached to the second stage for measuring a state of the exposure beam.

2. The exposure apparatus according to claim 1, wherein

An exposure apparatus, wherein the second stage is movably arranged independently of the first stage.

3. The exposure apparatus according to claim 1, wherein

An exposure apparatus comprising: a control device for moving the first stage between a position where the exposure beam is irradiated and a position where the exposure beam is not irradiated.

4. The exposure apparatus according to claim 2, wherein

An exposure apparatus, comprising: a controller that moves the second stage between a position where the exposure beam is irradiated and a position where the exposure beam is not irradiated.

5. The exposure apparatus according to claim 1, wherein

An exposure apparatus, comprising: a control device for positioning the second stage to a position where the exposure beam is not irradiated when the first stage is at a position where the exposure beam is irradiated.

6. Exposure to project the pattern formed on the mask onto the substrate via the projection optical system In the device,

A second stage independent of the first stage;

An exposure device, comprising: a measurement device arranged on the second stage to measure an imaging characteristic of the projection optical system.

7. The exposure apparatus according to claim 6, wherein

8. The exposure apparatus according to claim 6, wherein

The first stage holds the substrate,

A control device for moving the first stage between a position in an exposure area by the projection optical system and a predetermined position outside the exposure area.

9. The exposure apparatus according to claim 6, wherein

A control device for moving the second stage between a position in an exposure area by the projection optical system and a predetermined position outside the exposure area.

10. In an exposure device that transfers a pattern formed on a mask onto a substrate using an exposure beam,

An exposure apparatus, comprising: a stage on which a measurement device for measuring the state of the exposure beam is arranged; and a cooling device provided on the stage for cooling the measurement device.

1 1. In an exposure apparatus that projects a pattern formed on a mask onto a substrate via a projection optical system, A stage in which a measuring device for measuring the imaging characteristics of the projection optical system is arranged.

An exposure apparatus, comprising: a cooling device provided on the stage for cooling the measurement device.

1 2. In an exposure device that transfers a pattern formed on a mask onto a substrate using an exposure beam,

A second stage on which a measuring device for measuring the state of the exposure beam is mounted; and a second stage disposed between the first stage and the second stage to block heat conducted from the second stage. Exposure characterized by comprising: a heat insulating member;

13. The exposure apparatus according to claim 12, wherein

An exposure apparatus, wherein the heat insulating member is a solid material having a low thermal conductivity or a temperature-adjusted gas.

14. An exposure apparatus that projects a pattern formed on a mask onto a substrate via a projection optical system.

A first stage for holding the substrate and moving a predetermined area,

A second stage equipped with a measuring device for measuring the imaging characteristics of the projection optical system,

A heat insulating member disposed between the first stage and the second stage, and configured to block heat conducted from the second stage.

15. The exposure apparatus according to claim 14, wherein

16. An exposure method for transferring a pattern formed on a mask onto a substrate using an exposure beam,

A first stage for moving a predetermined area while holding one of the mask and the substrate;

A measuring device attached to a second stage independent of the first stage, and a step of measuring a state of the exposure beam.

17. The exposure method according to claim 16, wherein

The exposure method according to claim 1, wherein the second stage used in the measurement step is movably arranged independently of the first stage used in the transfer step.

18. The exposure method according to claim 16, wherein

The exposure method according to claim 1, wherein, in the moving step, the first stage moves depending on a position where the exposure beam is irradiated and a position where the exposure beam is not irradiated.

19. The exposure method according to claim 17, wherein

An exposure method, further comprising the step of: moving the second stage depending on a position where the exposure beam is irradiated and a position where the exposure beam is not irradiated.

20. The exposure method according to claim 16, wherein

An exposure method, further comprising the step of: positioning the second stage at a position where the exposure beam is not irradiated when the first stage is at the position irradiated with the exposure beam.

21. In an exposure method of projecting a pattern formed on a mask onto a substrate via a projection optical system, A first stage for moving a predetermined area while holding one of the mask and the substrate;

An exposure method, characterized in that a measuring device arranged on a second stage independent of the first stage includes a step of measuring an imaging characteristic of the projection optical system.

22. The exposure method according to claim 21, wherein

The exposure method according to claim 1, wherein the second stage used in the measuring step is movably arranged independently of the first stage used in the moving step.

23. The exposure method according to claim 21, wherein

The first stage holds the substrate,

The exposure method according to claim 1, wherein, in the moving step, the first stage moves between a position in an exposure area by the projection optical system and a predetermined position outside the exposure area.

24. The exposure method according to claim 21, wherein:

An exposure method, further comprising the step of: moving the second stage between a position within an exposure area by the projection optical system and a predetermined position outside the exposure area.

25. In an exposure method of transferring a pattern formed on a mask onto a substrate using an exposure beam,

A measuring device disposed on the stage, for measuring a state of the exposure beam;

An exposure method, wherein the cooling device provided on the stage includes a step of cooling the measuring device.

26. Exposure to project the pattern formed on the mask onto the substrate via the projection optical system In the optical method,

A measuring device arranged on the stage, for measuring an imaging characteristic of the projection optical system;

A cooling device provided on the stage, comprising: cooling the measuring device.

27. In an exposure method for transferring a pattern formed on a mask onto a substrate using an exposure beam,

Measuring a state of the exposure beam by a measuring device attached to the second stage;

An exposure member disposed between the first stage and the second stage to cut off heat conducted from the second stage.

28. The exposure method according to claim 27, wherein

The exposure method, wherein the heat insulating member used in the heat blocking step is a solid material having a low thermal conductivity or a gas whose temperature is adjusted.

29. In an exposure method for projecting a pattern formed on a mask onto a substrate via a projection optical system,

A first stage for moving the predetermined area while holding the substrate; a measuring device mounted on the second stage for measuring an imaging characteristic of the projection optical system;

An exposure member disposed between the first stage and the second stage to block heat conducted from the second stage.

30. The exposure method according to claim 29, wherein