JPH09223653A - Projection exposure equipment - Google Patents

Abstract

(57) Abstract: A drive offset amount of a reticle blind or the like can be easily obtained without using an actual substrate. A line sensor (3) is provided on a substrate stage (13).
1, 32 are provided, and the dimming area R by the reticle blind
The shot P is shot so that 1 and R2 are applied to the line sensors 31 and 32, and the dimming characteristic of the dimming region is measured. The drive start position and drive speed of the reticle blind are adjusted so that the dimming characteristic becomes a desired characteristic.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection exposure apparatus used for manufacturing semiconductor elements, liquid crystal displays and the like.

[0002]

2. Description of the Related Art In the manufacture of semiconductor devices and liquid crystal displays, a photosensitive substrate such as a wafer or glass on which a fine pattern image formed on a mask or reticle (hereinafter referred to as a reticle) is coated with a photoresist by a projection exposure apparatus. Projection exposure is performed. In this projection exposure apparatus, in order to cope with the increase in the size of the photosensitive substrate, the exposure area of the photosensitive substrate is divided into a plurality of unit areas, the exposure according to each unit area is repeated, and finally a screen for synthesizing a desired pattern is displayed. Synthetic methods have been used.

When synthesizing screens, a pattern is formed at the boundary position of each exposure area due to a drawing error of a reticle for pattern projection, an aberration of a lens of a projection optical system, a positioning error of a stage for positioning a photosensitive substrate, and the like. In order to prevent the occurrence of breaks, the exposure is performed by superimposing a minute amount of the boundaries of the exposure areas. However, if the exposure areas are simply overlapped, the exposure amount of the overlapped portion is doubled, and the line width of the seam portion of the pattern may change depending on the characteristics of the photoresist. Further, when the screen synthesis is performed, a step may occur at the seam portion of the pattern due to the displacement of the positions of the adjacent exposure regions, and the characteristics of the device may be impaired. Furthermore, when the work of superimposing a single-layer pattern formed by screen composition into multiple layers is shared by different exposure devices for each layer, the exposure area of each layer may differ due to the difference in lens aberration and positioning accuracy between the exposure devices. The overlay error occurs discontinuously at the seam portion of the pattern, and particularly in an active matrix liquid crystal device, the contrast changes intermittently at the seam portion of the pattern, resulting in a significant deterioration of the device quality.

As a means for eliminating such inconvenience in screen composition, Japanese Patent Publication No. Sho 63-49218 discloses a method for reducing the amount of transmitted light at a position corresponding to a pattern joint portion of a reticle or a filter to be superimposed on the reticle. There is described a method in which a light means is provided and the exposure amount of the overlapping portion of the pattern is matched with the exposure amount of the other portion. Further, in Japanese Patent Application Laid-Open No. 6-302501, a movable reticle blind is provided in an illumination optical system that irradiates a reticle with exposure light from a light source, and an illumination area on the reticle is continuously exposed during exposure of a photosensitive substrate. A method is described in which the exposure amount of the overlapping portion of the pattern is made substantially equal to the exposure amount of the other portion by changing.

[0005]

In the method of dimming the peripheral portion of the exposure area by moving the reticle blind during exposure, if the drive start position of the reticle blind is deviated, the exposure amount of the pattern overlapping portion is changed. Cannot be uniform. Further, the reticle blind is driven by a drive means such as a DC motor, but the applied voltage required to obtain a predetermined moving speed is small depending on the device because the load of each drive means and the drive mechanism is different. Different to Therefore, a representative value is set for the voltage applied to the driving means, and the machine difference from the representative value is given to each projection exposure apparatus as a fixed offset amount. This offset amount was obtained by actually exposing the photosensitive substrate when adjusting the projection exposure apparatus, and was set as an apparatus constant.

The shutter provided in the illumination optical system is
Opening and closing is controlled by a method of closing the shutter after a preset time has elapsed after opening the shutter, or a method of closing the shutter when the integrated exposure amount reaches a predetermined value by monitoring the exposure amount during exposure. In either method, the light output from the light source of the exposure apparatus decreases due to deterioration as the light source usage time increases, and therefore the exposure time gradually increases when the photosensitive substrate is exposed with a desired exposure amount. Therefore, it is necessary to change the reticle blind moving speed, that is, the offset amount according to the change of the shutter opening time, but in the conventional method, the actual substrate is exposed and then developed each time, and the pattern actually formed is changed. It is necessary to measure and obtain an offset value that has changed over time, and a great deal of labor was required to adjust the reticle blind.

The present invention has been made in view of the above problems of the prior art, and provides a projection exposure apparatus capable of easily obtaining a drive offset amount of a reticle blind or the like without using an actual substrate. The purpose is to do.

[0008]

In the present invention, an illuminance measuring sensor provided on a substrate stage is used to dimming characteristics of a peripheral dimming means for dimming a peripheral area of an exposure area such as a driving reticle blind. The object is achieved by measuring

That is, according to the present invention, an illuminating optical system for irradiating a reticle with a light beam from a light source and a photosensitive substrate are mounted.
A substrate stage movable in a dimensional direction, a projection optical system for forming a pattern image of a reticle on a photosensitive substrate, and a peripheral dimming unit arranged at a position conjugate with the reticle in an illumination optical system are provided. In a projection exposure apparatus that reduces the integrated exposure amount of the peripheral portion of the pattern image formed on the photosensitive substrate by the light attenuating unit as the distance from the center of the pattern image increases, the illuminance measuring unit provided on the substrate stage is provided. The present invention is characterized by comprising adjusting means for adjusting the peripheral dimming means so that the peripheral dimming characteristic measured by the illuminance measuring means becomes a desired dimming characteristic. The illuminance measuring means may be one or a plurality of line sensors or a spot-like illuminance sensor.

When the adjusting means forms a plurality of pattern images on the photosensitive substrate by shifting the positions while overlapping the peripheral portions of the adjacent pattern images with each other, the exposure amount at the overlapping position of each pattern image is out of the overlapping range. The peripheral dimming unit is adjusted so that the exposure amount is substantially equal to the exposure amount.

A diaphragm member (reticle blind) for defining the area of the opening through which the light flux from the light source passes by the peripheral light attenuating means.
And an aperture control unit that changes the position of the aperture member during exposure, the adjusting unit may adjust at least one of the drive start position and the drive speed of the aperture member.

Further, when the peripheral dimming means is constituted by a filter (density wedge filter) which is arranged at the periphery of the opening through which the light beam from the light source passes and whose transmittance decreases as the distance from the center of the opening is increased, The adjusting means adjusts the position of the peripheral dimming means with respect to the optical axis of the illumination optical system.

According to the present invention, in the projection exposure apparatus using the screen synthesis method, the measurement and correction of the extinction characteristic of the peripheral extinction means for adjusting the exposure amount of the exposure areas to be superposed are performed without using the actual substrate. Since it can be done automatically, the work amount when adjusting the peripheral dimming means can be greatly reduced, and even when the projection exposure apparatus is arranged inline, the peripheral line can be reduced without stopping the upstream line. It is possible to adjust the light means.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of a projection exposure apparatus that performs screen composition using a driving reticle blind. The illumination light emitted from the extra-high pressure mercury lamp 1 is condensed by the elliptical mirror 2 and enters the wavelength selection filter 5 from the reflecting mirror 4 in response to the opening / closing operation of the shutter 3. The wavelength selection filter 5 passes only the wavelength required for exposure, and the illumination light that has passed through the wavelength selection filter 5 is adjusted by the fly-eye integrator 6 into a luminous flux having a uniform illuminance distribution and reaches the reticle blind 7. A reticle blind (hereinafter, simply referred to as a blind) 7 changes the size of the opening S to adjust the illumination range on the reticle 10 by the illumination light. Further, a part of the light flux emitted from the fly-eye integrator 6 is reflected by the half mirror 16 and enters the integrated exposure amount meter 17, and the integrated exposure amount meter 1
Based on the output of 7, the opening / closing time control of the shutter 3, that is, the exposure amount control is performed.

Illumination light that has passed through the opening S of the blind 7 is reflected by the reflecting mirror 8 and enters the lens system 9, and the image of the opening S of the blind 7 is reflected by the lens system 9 by the reticle 10.
Imaged above, the desired area of reticle 10 is illuminated.
The image of the pattern existing in the illumination range of the reticle 10 is imaged on the photosensitive substrate 12 such as a wafer or a glass plate coated with a photoresist by the projection optical system 11, and thereby the reticle 10 is formed on a specific area of the photosensitive substrate 12. Pattern image is exposed.

The photosensitive substrate 12 is fixed on the stage 13. The stage 13 is a known one in which a pair of blocks movable in directions orthogonal to each other are superposed, and the position of the photosensitive substrate 12 in the horizontal plane is adjusted by the stage 13. When synthesizing screens, after one exposure of a reticle (pattern area) is completed, the reticle 10 is replaced and the stage 13 is driven to move another area of the photosensitive substrate 12 to the projection optical system 11. Position and expose. Thereafter, the same procedure is repeated each time the exposure is completed, and the entire area of the photosensitive substrate 12 is exposed. In addition, a plurality of types of patterns are formed on one reticle, and the photosensitive substrate 12
The screen 7 may be combined by changing the illumination range of the reticle by the blind 7 (changing to a different pattern area) in association with the change of the exposure area of. The position of the stage 13 is
Laser light 15 is emitted toward the moving mirror 14 on the stage 13, and is detected by a laser interferometer 20 that measures the distance based on the interference between the reflected light and the incident light.

As shown in FIG. 2, the blind 7 is a combination of a pair of blades 7a and 7b bent in an L shape in a state in which they are orthogonal to the optical axis AX of the illumination light to generate a rectangular opening S. Then, the positions of the blades 7a and 7b are adjusted by the drive mechanisms 18a and 18b shown in FIG. 1 to change the size of the opening S. As shown in FIGS. 3 and 4, the drive mechanism 1
8a and 18b are first blades 7a and 7b
The second block 711 and the third block 712 are overlapped with the block 710 of FIG. The second block 711 is moved along with the guide groove x
1 and x2 to move the blades 7a and 7b in a plane perpendicular to the optical path of the illumination light. As shown in FIG. 4, the drive mechanisms 18a and 18b are arranged on opposite sides of the blades 7a and 7b, and the third blocks 712 are integrally fixed to the main body of the exposure apparatus by a frame (not shown). .

Shutter 3 and drive mechanisms 18a and 18b
Are controlled by the controller 19. That is, after setting the blind 7 for the pattern area of the reticle 10 to be exposed, the shutter 3 is opened by a command from the control device 19 and the exposure of the photosensitive substrate 12 is started. The movement of the blind 7 is started in synchronization with the operation of the shutter 3, and the integrated exposure amount meter 17 measures the integrated exposure amount. Then, when the exposure amount measured by the integrated exposure amount meter 17 reaches a predetermined value, the shutter 3 is closed and the movement of the blind 7 is ended. The moving speed of the blind 7 is set so that the blind moves by a distance corresponding to a region to be screen-combined while the shutter 3 is open.

FIG. 5 shows the concept of an exposure method using a blind. When exposing two different pattern areas A and B as shown in FIGS. 5A and 5B so that the hatched portions overlap each other, first, as shown in FIG. 5C, the reticle blind 7 is placed on the pattern area A. Set the white part of. Then, as shown in FIG. 5D, while illuminating the pattern area A (during exposure), the reticle blind 7 corresponding to the hatched portion of the pattern area.
Drive in the direction of the arrow. As a result, as shown in FIG. 5E, the exposure amount on the photosensitive substrate continuously decreases toward the end at the portion corresponding to the hatched portion.

FIG. 6 shows an exposure image and an exposure amount distribution on the photosensitive substrate when the size of the opening of the reticle blind 7 is appropriately determined and exposure is performed in the state without the reticle. FIG.
(A) shows two different shots P1 and P2 projected on the photosensitive substrate adjacent to each other, and hatching regions R1 and R2 at the ends thereof are dimming regions due to movement of the reticle blind 7. In the dimming regions R1 and R2, the exposure amount is reduced by the operation described with reference to FIG. FIG.
As shown in (b), when both shots are combined, the exposure amount distribution of each shot becomes as shown in FIG. 6 (c),
In the overlapping range of the dimming regions R1 and R2, one dimming amount changes so as to compensate for the variation of the other dimming amount, and as a result, as shown in FIG.
As shown in (d), the combined exposure amount in the overlapping portion of the dimming regions R1 and R2 matches the exposure amount in the white portion in FIG. 6A which is not affected by the reticle blind.

In this example, the blade 7 of the blind 7
a and 7b (only one blade 7a in the example of FIG. 5) is moved during the exposure so that the opening S is gradually enlarged, and by this operation, the exposure range A1- on the photosensitive substrate 12 corresponding to the enlarged portion of the opening S1- The exposure amount of A2 is decreased toward the end of the opening S in the expansion direction at a constant rate. In the example of FIG. 5, the blade 7a is moved in one direction to reduce the exposure amount on only one side of the exposure area of the photosensitive substrate 12, but if the blade 7a is simultaneously driven in two directions, the exposure of two sides of the exposure area is performed. If the blades 7a and 7b are simultaneously driven in two directions, the exposure amount of the entire circumference of the exposure area can be reduced. Even if the aperture S is gradually reduced during exposure, the exposure amount can be reduced.

An example of controlling the movement of the blind 7 will be described with reference to FIGS. 7 and 8. FIG. 7 (a) is shown in FIG.
The output obtained by the integrated exposure meter 17 shown in
This is equivalent to one obtained by one shutter opening / closing operation. FIG. 2B shows a change in the moving speed of the blind with time. This control example uses the integrated exposure meter 17
Blind 7 the voltage obtained by multiplying the output of
It is used as it is as a speed command voltage for the movement. In this case, even if the illuminance of the light source 1 deteriorates, the speed of the blind 7 automatically follows and slows down, and proper exposure is realized. Further, since the output of the integrated exposure meter 17 is output according to the opening / closing of the shutter 3, the shutter 3 is completely output.
The blind 7 can be moved in synchronization with. The above multiplier is set so that when the blind 7 is moved based on the waveform representing the change in the moving speed of FIG. 2B, the moving amount of the blind 7 becomes a distance corresponding to the overlapping width of the exposure area. Is a multiplier for.

FIG. 8 is a block diagram of a control system for controlling the speed of the blind as shown in FIG. 7 (b).
The output of the integrated exposure meter 17 is amplified by the amplifier 21. The output of the amplifier 21 is input to the integrating circuit 22 and the multiplier 25. On the other hand, the above-mentioned multiplier is output from the output port of the microprocessor 23 and input to the other input of the multiplier 25 via the D / A converter 24. The output from the multiplier 25 is input to the servo circuit 26 and drives a blind driving motor 27.

The drive control of the blind may be a method of simply controlling the drive of the blind in synchronization with the opening and closing of the shutter 3 as long as the fluctuation of the illuminance of the light source can be ignored. Next, a method of measuring the extinction characteristic with the reticle blind will be described. FIG. 9 shows the stage 13 of the exposure apparatus.
FIG. On the stage 13, line sensors 31, 32 such as linear CCD sensors are provided along the X direction. The line sensors 31 and 32 are the stage 13
When the shot P is projected on the upper side, the width of the dimming regions R1 and R2 due to the movement of the blind 7 in the shot P [FIG.
(E) has a length sufficient to cover A1-A2]. The dimming region R1 is formed by the movement of the blade 7a, and the dimming region R2 is formed by the movement of the blade 7b.

FIG. 10 is an enlarged view showing the positional relationship between the shot P of FIG. 9 and the line sensors 31 and 32. The blades 7a and 7b of the blind are assumed to be driven from the peripheral portion of the shot toward the central portion as indicated by arrows a and b in the figure. Now, the dimming regions R1 and R2 of the shot P
However, as shown in FIG. 10, the stage 13 is moved to such a position as to reach the line sensors 31 and 32, respectively, and the blades 7a and 7b of the blind 7 are driven to perform the shot. Line sensors 31, 3 shown by dots in FIG.
Each element of No. 2 measures and integrates the illuminance during a shot with a sufficiently short sampling time, and measures the integrated exposure amount at the measurement point.

FIG. 11B shows line sensors 31, 32.
It is a plot of the measurement results obtained in accordance with the overlapping range. If exposure is performed as it is with this blind setting, the combined exposure amount of the portion where the dimming regions R1 and R2 are overlapped changes as shown in FIG. 11C, and it can be seen that uneven exposure occurs in the overlapped portion. . It should be noted that FIG. 11A shows a synthetic exposure dose curve of overlay exposure by an ideally adjusted blind.

Therefore, the blind drive is corrected based on the result of FIG. 11 (b). First, looking at the exposure amount curve b of the left blind, it rises earlier than the ideal overlapping range shown in FIG. Therefore, it can be determined that it is necessary to offset the blind drive start position. The error amount of the rising position can be obtained from the position coordinates of the stage. On the contrary, the exposure amount curve a of the right blind rises late. Therefore, it is necessary to apply an offset opposite to that of the left blind to the drive start position of the right blind.

As a result of offsetting the driving start positions of the left-side blind driving and the right-side blind driving in this way, exposure amount curves a and b, that is, dimming characteristics as shown in FIG. 12A are obtained. When overlay exposure is performed in this state, the combined exposure amount varies depending on the location as shown in FIG. 12B, and exposure unevenness also occurs in the overlay portion. From FIG. 12A, it can be seen from the exposure amount curve b by the left blind that the driving end position of the left blind is cut into the non-overlapping exposure part. That is, it can be determined that the driving speed of the left blind is too high. On the contrary, from the exposure amount curve a, it can be seen that the blind drive is completed before the blind reaches the predetermined position. Therefore, it can be determined that the driving speed of the right blind is slow.

Therefore, when the blind driving speed is corrected by adjusting the voltage applied to each blind driving motor or the value of the multiplier stored in the microprocessor 23, the exposure amount curve a in FIG. 13A is obtained. , B
The dimming characteristic shown by can be realized. In this case, the combined exposure amount due to the superposition of the dimming regions R1 and R2 is uniform and equal to the exposure amount of the non-overlapping portion as shown in FIG. 13B.

In the above description, the pair of line sensors 31 and 32 are provided on the stage 13 to simultaneously measure the extinction characteristics of the extinction regions R1 and R2 on the left and right of the shot. However, only one line sensor is provided on the stage 13, and the stage 13 is first moved so that the line sensor covers the dimming region R1 to measure the dimming characteristic of the dimming region R1. Alternatively, the stage 13 may be moved so as to cover the other dimming region R2 and the dimming characteristic of the dimming region R2 may be measured. Further, instead of the line sensor, one or a plurality of spot-like illuminance sensors are provided on the stage 13, and the position of the illuminance sensor with respect to the dimming region R1 or R2 is sequentially moved by a minute distance in the X direction by moving the stage. By repeating the shots, the exposure amount data of the dimming region as shown in FIGS. 11 to 13 can be obtained.

Although the measurement and adjustment of the extinction characteristic of the extinction region set at the end of the exposure region in the X direction has been described here, one or one on the stage 13 along the Y direction.
By providing a pair of line sensors or by using one or a plurality of illuminance sensors provided on the stage 13, the dimming area set at the end of the exposure area in the Y direction is reduced in a similar manner. It is possible to measure the light characteristics and adjust the drive start position and drive speed of the reticle blind based on the result.

Next, an explanation will be given of the adjustment in the case where a density wedge filter, that is, a density filter whose transmittance decreases as the distance from the center of the opening is used instead of the reticle blind as the peripheral light reduction means in the exposure area.

In the example described here, the blind 6 shown schematically in FIG. 14 is placed at the position of the drive reticle blind in FIG.
0 is placed. The blind 60 creates a rectangular opening S by combining a pair of blades 60a and 60b that are bent in an L shape in a state of being orthogonal to the optical path of the illumination light, as shown in FIGS. The size of the opening S can be changed by adjusting the positions of the blades 60a and 60b by a similar drive mechanism. The blades 60a and 60b are obtained by integrally mounting the ND filters 601a and 601b on the surfaces of the light shielding plates 600a and 600b, and the end portions of the ND filters 601a and 601b on the side of the opening S are slightly projected from the light shielding plates 600a and 600b. It is provided. The aperture S of the blind 60 is fixed during exposure, and the image of the aperture S is formed on the reticle 10 by the lens 9.

As shown in the cross-sectional view of FIG. 15, the protruding portions of the ND filters 601a and 601b from the light shielding plates 600a and 600b are formed in a triangular cross-section that becomes thinner in proportion to the amount of protrusion from the light shielding plates 600a and 600b. , So that the transmittance of the blind 60 is 100% on the aperture S and the aperture S
In the peripheral portion of the light shielding plate 600, the distance decreases from the center position of the opening S to 0% at the edge positions of the light shielding plates 600a and 600b. The amount L of protrusion of the ND filters 601a and 601b from the light shielding plates 600a and 600b is constant over the entire circumference of the opening S, so that the dimming characteristics in the peripheral portion of the opening S are the diagonal of the opening S where the ND filters overlap. It is the same on all sides except the corners. Therefore, by overlapping the dimming regions by the ND filters 601a and 601b so that the shots are adjacent to each other, the exposure amount of the overlapping portion can be made uniform and the same as the exposure amount on the opening S.

Even when a darkening area is formed around the exposure area using the density wedge filter, if the setting position of the blind 60, that is, the setting of the darkening area by the density wedge filter is deviated, the adjacent shot A uniform exposure amount cannot be obtained when the dimming regions are overlapped. Therefore, it is necessary to measure the extinction characteristic of the extinction region and adjust the position of the blind 60.

The extinction characteristic of the extinction area formed by the density wedge filter can be measured by the same method as the extinction characteristic of the extinction area formed by the moving reticle blind. For example, as shown in FIGS. 9 and 10, the line sensor 3 such as a linear CCD sensor is used.
1 and 32 are used, the stage 13 is moved to a position where the light reduction area by the density wedge filter hits the line sensors 31 and 32, and a shot is projected to determine the exposure amount distribution of the light reduction area. Measure. Then, the position of the blind 60 is adjusted so that the position of the rising portion of the measured exposure amount distribution curve becomes the predetermined position.

In this way, by measuring the extinction characteristics of the extinction area formed by the peripheral extinction means such as the reticle blind and the density wedge filter, and automatically correcting the extinction characteristics, it is possible to perform the intervention manually. It is possible to maintain high exposure quality for screen synthesis. Further, even in the projection exposure apparatus arranged in-line, it is possible to adjust the peripheral dimming means without interrupting the flow of the photosensitive substrate.

When performing measurement using the integrated exposure amount by one or a plurality of spot-like illuminance sensors, accurate adjustment cannot be performed unless the exposure amounts at the respective measurement points are equal. . However, in reality, a slight error may occur in the exposure amount for each shot due to an output variation of the light source, an error in the shutter opening / closing timing, and the like. Therefore, in the case of performing the above measurement, the actual exposure amount is also measured for each shot at the same time, and by calibrating the measurement value of the integrated exposure amount by the illuminance sensor according to the result, it is possible to perform adjustment with higher accuracy. Become.

FIG. 16 shows an example in which the measurement value of the integrated exposure amount by the illuminance sensor is calibrated by the actual exposure amount measurement value. FIG.
6, the horizontal axis represents the position of the illuminance sensor and the vertical axis represents the measured exposure amount. In the figure, Δ represents the measured value by the illuminance sensor, and ◯ represents the actual exposure amount measured by the integrated exposure meter 17 in FIG. Since the actual exposure amount changes for each shot,
The value measured by the illuminance sensor contains an error due to the fluctuation. Therefore, each measurement value by the illuminance sensor is calibrated to a value when the actual exposure amount is the illustrated constant reference exposure amount. The exposure amount curves a and b as shown in FIG. 11 are created by using the data of the exposure amount (indicated by X) thus calibrated, and the driving start position of the driving reticle blind, the offset amount of the driving speed, or the density wedge The setting light error of the filter is detected to adjust the peripheral dimming means.

Although the adjustment of the peripheral dimming means for screen composition using the drive reticle blind or the density wedge filter has been described so far, the present invention is not limited to the adjustment of the peripheral dimming means, and it is not limited to normal projection. The present invention can also be applied to the offset and scaling adjustment of blinds provided to limit the exposure range of the exposure apparatus.

[0041]

According to the present invention, in the projection exposure apparatus using the screen synthesis method, the measurement and the correction of the extinction characteristic of the peripheral extinction means for adjusting the exposure amount of the overlapped areas are performed without using the actual substrate. Since it can be performed automatically, it is possible to significantly reduce the work amount when adjusting the peripheral dimming means, and even when the projection exposure apparatus is arranged inline,
The peripheral dimming means can be adjusted without stopping the upstream line.

[Brief description of drawings]

FIG. 1 is a schematic view of a projection exposure apparatus according to the present invention.

FIG. 2 is a front view of a blade portion of the reticle blind.

FIG. 3 is a schematic diagram of a reticle blind drive mechanism.

4 is a schematic configuration diagram of an AA cross section of the blade shown in FIG. 2 and a driving mechanism.

FIG. 5 is a diagram showing a positional relationship between a reticle and a blade when screens are combined.

FIG. 6 is a diagram showing a relationship between an exposure image and an exposure amount on a photosensitive substrate.

FIG. 7 (a) is a diagram showing the output of an integrated exposure meter, (b).
FIG. 4 is a diagram showing a change in moving speed of a reticle blind.

FIG. 8 is a block diagram of a reticle blind control system.

FIG. 9 is a top view of the stage.

FIG. 10 is a diagram showing a positional relationship between a line sensor and a shot.

FIG. 11 is a diagram showing a result of exposure amount measurement.

FIG. 12 is a diagram showing an exposure amount curve after adjustment of a blind drive start position.

FIG. 13 is a diagram showing an exposure amount curve after blind drive speed correction.

FIG. 14 is a schematic front view of another example of the blind.

15A and 15B are cross-sectional views taken along line BB in FIG. 14 and the transmittance of the cross-section.

FIG. 16 is a diagram illustrating correction of an integrated exposure amount measured by an illuminance sensor.

[Explanation of Codes] 1 ... Ultra-high pressure mercury lamp, 2 ... Elliptical mirror, 3 ... Shutter,
4 ... Reflecting mirror, 5 ... Wavelength selecting filter, 6 ... Fly eye integrator, 7 ... Reticle blind, 7a, 7b ...
Blade, 8 ... Reflecting mirror, 9 ... Lens system, 10 ... Reticle, 11 ... Projection optical system, 12 ... Photosensitive substrate, 13 ... Stage, 14 ... Moving mirror, 15 ... Laser light, 17 ... Integrated exposure meter, 18a, 18b ... Driving mechanism, 19 ... Control device, 20
... interferometer, 21 ... amplifier, 22 ... integration circuit, 23 ... microprocessor, 24 ... D / A converter, 25 ... multiplier, 26 ... servo circuit, 27 ... motor, 31, 32 ... line sensor, 60 ... blind, 60a, 60b ... Blades, 600a, 600b ... Shading plates, 601a, 601
b ... ND filter, 710 ... First block, 711 ...
Second block, 712 ... Third block, P ... Shot, R1, R2 ... Dimming area, S ... Opening

Claims (4)

[Claims] 1. An illumination optical system for irradiating a reticle with a light beam from a light source, a substrate stage on which a photosensitive substrate is placed and movable in two dimensions, and a pattern image of the reticle is formed on the photosensitive substrate. A projection optical system and a peripheral dimming unit arranged at a position conjugate with the reticle in the illumination optical system, and integrating the peripheral portion of the pattern image formed on the photosensitive substrate by the peripheral dimming unit. In a projection exposure apparatus that reduces the exposure amount as it moves away from the center of the pattern image to perform exposure, illuminance measuring means provided on the substrate stage, and extinction of the peripheral dimming means measured by the illuminance measuring means. A projection exposure apparatus comprising: an adjusting unit that adjusts the peripheral dimming unit so that a characteristic has a desired dimming characteristic. 2. When the adjusting means forms a plurality of pattern images on the photosensitive substrate by shifting the positions while overlapping the peripheral portions of the adjacent pattern images with each other, the amount of light at the overlapping position of the pattern images is reduced. 2. The projection exposure apparatus according to claim 1, wherein the peripheral light attenuating unit is adjusted so as to be substantially equal to the light amount outside the overlapping range. 3. The peripheral dimming unit includes a diaphragm member that defines an area of an opening through which a light beam from the light source passes, and a diaphragm control unit that changes a position of the diaphragm member during exposure. The projection exposure apparatus according to claim 1 or 2, wherein the means adjusts at least one of a drive start position and a drive speed of the diaphragm member. 4. The peripheral dimming means is a filter that is arranged at the periphery of an opening that allows a light beam from the light source to pass therethrough, and the transmittance decreases as the distance from the center of the opening increases, and the adjusting means includes the illumination optical means. 3. The projection exposure apparatus according to claim 1, wherein the position of the peripheral dimming means with respect to the optical axis of the system is adjusted.