JPH07135132A - Projection exposure device - Google Patents

Abstract

(57) [Summary] [Object] In a slit scan exposure type projection exposure apparatus, when the sensitivity of the photosensitive material coated on the wafer changes, the scanning speed of the stage is kept below the upper limit and The exposure amount control accuracy is maintained at high accuracy. [Structure] Illumination light from a mercury lamp 31 passes through a fly-eye lens 36, a relay lens 37A, movable reticle shading plates 38 and 39, fixed reticle blinds 42 and 43, a relay lens 37B and a condenser lens 45, and a slit on the reticle 1. The illumination area 46 is illuminated. The pattern in the illumination area 46 is transferred to the wafer 1 via the projection optical system 9.
0 is exposed. The width of the illumination area 46 in the scanning direction is changed via the fixed reticle blinds 42 and 43 according to the sensitivity of the photoresist on the wafer 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called slit scan exposure type projection exposure apparatus which is used, for example, in manufacturing a semiconductor element, a liquid crystal display element or the like in a photolithography process.

[0002]

2. Description of the Related Art Conventionally, when a semiconductor element, a liquid crystal display element, a thin film magnetic head or the like is manufactured by using a photolithography technique, a photomask or a reticle (hereinafter, referred to as
A projection exposure apparatus that exposes a pattern (collectively referred to as “reticle”) onto a wafer (or a glass plate or the like) coated with a photoresist or the like via a projection optical system is used. Recently, a single chip pattern such as a semiconductor element tends to be large, and a projection exposure apparatus is required to have a large area for exposing a pattern having a larger area on a reticle onto a wafer. .

Further, it is required to improve the resolution of the projection optical system in accordance with the miniaturization of the pattern of the semiconductor element or the like. However, the resolution of the projection optical system is improved and the exposure of the projection optical system is performed. There is a problem in that it is difficult in terms of design and manufacturing to increase the field. In particular, when a catadioptric system is used as the projection optical system, the aberration-free exposure field may have an arcuate region.

In order to cope with such a large area of the pattern to be transferred and the limitation of the exposure field of the projection optical system, for example, an elongated rectangular, arcuate or hexagonal illumination area (this is called a "slit-shaped illumination area"). ) Is scanned by the reticle, and the wafer is scanned in synchronism with the reticle for the exposure area that is conjugate with the illumination area, so that the image of the pattern on the reticle is sequentially exposed on the wafer. The projection exposure apparatus has attracted attention.

In the slit scan exposure system, assuming that the magnification of the projection optical system is β, the wafer is scanned at a speed β · V in a direction conjugate with the scanning direction of the reticle in synchronization with the scanning of the reticle at a speed V. To be done. In addition, the sensitivity of the photosensitive material (photoresist etc.) applied on the wafer determines the target exposure amount of the integrated exposure amount for the wafer. To set the integrated exposure amount to the target exposure amount, the light amount of illumination light is set. It is necessary to keep the width of the slit-shaped exposure area on the wafer in the scanning direction and the scanning speed of the wafer in a predetermined relationship.

In this regard, conventionally, when a photosensitive material having a sensitivity different from that used in the previous steps is used, exposure is mainly performed by increasing or decreasing the scanning speed of the wafer and reticle. The quantity was controlled. Then, when the scanning speed of the wafer or reticle reaches the upper limit value, a neutral density filter plate is inserted in the optical path of the illumination light,
The exposure amount was controlled by reducing the illuminance of the illumination light.

[0007]

In the projection exposure apparatus of the slit scan exposure system as described above, in the system in which the scanning speed of the wafer and the reticle is changed to control the exposure amount according to the sensitivity of the photosensitive material, the photosensitive material is used. However, there is a disadvantage that the scanning speed of the wafer or reticle reaches the upper limit value (the maximum scanning speed of the mechanical stage), and the exposure amount cannot be controlled any more.

Further, in the system in which the illuminance of the illumination light is reduced by the dimming filter plate when the scanning speed of the wafer or reticle reaches the upper limit value, by disposing the dimming filter plate in the illumination optical system, There is a possibility that flare or the like may be mixed in the illumination light. Further, there are problems such as heat generation of the neutral density filter plate due to the exposure light and dust generation due to the removal of the neutral density filter plate. Furthermore, when adjusting the illuminance of the illumination light, the illuminance of the illumination light on the exposed surface of the wafer is not always stable, and even if the power supplied to the light source is kept constant, it gradually decreases due to aging. There was the inconvenience of going.

In view of the above point, the present invention, in a slit scan exposure type projection exposure apparatus, suppresses the scanning speed of the stage to the upper limit value or less when the sensitivity of the photosensitive material coated on the wafer changes. Moreover, it is an object of the present invention to maintain the control accuracy of the integrated exposure amount for the wafer with high accuracy. Another object of the present invention is to enable a slit exposure exposure type projection exposure apparatus to maintain a high level of accuracy in controlling the integrated exposure amount for a wafer even when the illuminance of illumination light changes.

[0010]

A first projection exposure apparatus according to the present invention is, for example, as shown in FIG. 1, an illumination optical system for illuminating an illumination area on a mask (1) with illumination light, and the illumination area. And a projection optical system (9) for projecting an image of the pattern of the mask (1) on a substrate (10) coated with a photosensitive material, and a mask for scanning the illumination area with the mask (1) in a predetermined direction. The substrate-side stage (12, 4) that scans the substrate (10) in a predetermined direction with respect to the exposure region that is conjugate with the illumination region in synchronization with the scanning of the side stage (3, 4) and the mask (1).
13), and a sensitivity input for inputting the sensitivity of the photosensitive material coated on the substrate (10) in a scanning projection exposure apparatus that sequentially exposes the image of the pattern of the mask (1) on the substrate (10). Means (17).

Further, according to the present invention, the illumination area on the mask (1) by the illumination light is set to a predetermined shape (46), and the width of the illumination area (46) of the predetermined shape in the scanning direction is arbitrarily set within a predetermined range. Variable field diaphragm (42, 4)
3), the light amount detecting means (14) for detecting the exposure energy of the illumination light, the sensitivity of the photosensitive material input by the sensitivity input means (17), and the illumination light detected by the light amount detecting means (14) Of the exposure area of the mask and the scanning speed of the mask (1) by the mask-side stage (3, 4) equal to or less than the predetermined upper limit value, the width in the scanning direction of the illumination area (46) on the mask (1) is obtained. Computing means (7)
And the illumination area (46) obtained by the computing means (7)
And a control means (41) for setting the width of the field through the variable field diaphragms (42, 43).

The second projection exposure apparatus according to the present invention is, for example, as shown in FIG. 1, an illumination optical system for illuminating an illumination area on the mask (1) with illumination light, and a mask ( A projection optical system (9) for projecting an image of the pattern of 1) onto a substrate (10) coated with a photosensitive material, and a mask side stage (3) for scanning the illumination area with the mask (1) in a predetermined direction. , 4) and a substrate-side stage (12, 13) for scanning the substrate (10) in a predetermined direction with respect to an exposure region which is conjugate with the illumination region in synchronization with the scanning of the mask (1). Images of the pattern of (1) are successively printed on the substrate (10).
In a scanning type projection exposure apparatus that exposes light to the upper side, an illumination area on the mask (1) by the illumination light is formed into a predetermined shape (46).
And a variable field stop (42, 43) for setting the width of the illumination area (46) of a predetermined shape in the scanning direction to an arbitrary width within a predetermined range.

The present invention further provides a substrate (10) for the illumination light.
Light amount detecting means (14) for detecting the exposure energy on the mounting surface of, and the mask side stage (3, 3) having a preset sensitivity of the photosensitive material or less than a predetermined upper limit value.
Calculation means for obtaining the width in the scanning direction of the illumination area (46) on the mask (1) from the scanning speed of the mask (1) according to 4) and the exposure energy of the illumination light detected by the light amount detection means (14). (7) and the width of the illumination area (46) obtained by the calculation means (7) is set to the variable field stop (42,
43), and a control means (41) for setting via the same.

[0014]

According to the first projection exposure apparatus of the present invention,
Set the projection magnification of the projection optical system (9) to β (for example, β = 1 /
5), the slit width of the exposure area (47) on the exposure surface of the substrate (10) is L _W , and the illumination area (4) on the mask (1)
If the slit width of 6) is L _R , the slit widths L _W and L
It has the following relationship with _R.

L _R = (1 / β) L _W (1) When the scanning speed of the substrate (10) is V _W and the scanning speed of the mask (1) is V _R , the scanning speeds V _R and V _W Similarly, the relationship with is as follows. V _R = (1 / β) · V _W (2) Now, if the illuminance of the illumination light on the substrate (10) is p and the sensitivity (target exposure amount) of the photosensitive material on the substrate (10) is e, The exposure time t for obtaining the target exposure amount at one point on the substrate (10) can be expressed as follows.

[0016] t = e / p (3) Further, equation (1) and (2), when crossing the exposed areas of the slit width L _W (47) at a scan rate V _W, the substrate (1
The exposure time t'of one point on 0) can be expressed as follows. t ′ = L _W / V _W (4) In order to make the time t in the equation (3) equal to the time t ′ in the equation (4) (t = t ′), the following condition is necessary.

E / p = L _W / V _W (5) By substituting the equation (2) into this, the scanning speed V _R of the mask (1) can be expressed as follows. V _R = L _W · p / (β · e) (6) Therefore, when the slit width L _W , the illuminance p, and the projection magnification β are constant, the mask (1 ) can be determined scanning speed V _R of the. In this case, since the projection magnification β of the projection optical system (9) is generally smaller than 1, the substrate (1
The scanning speed V _R of the mask (1) is faster than the scanning speed V _W of 0). Therefore, the scanning speed V of the mask (1)
_R is easier to reach the upper speed limit.

Therefore, assuming that the upper limit of the scanning speed V _R of the mask (1) is V _max , the following relationship is established from the equation (6). V _R = L _W · p / (β · e)> V _max (7) Therefore, when using a high-sensitivity (small sensitivity e) photosensitive material, make sure that the scanning speed does not reach the upper limit value. There are the following two methods from Equation (7). The illuminance p of the illumination light on the substrate (10) is reduced. Slit width L of the exposure area (47) on the substrate (10)
_W is reduced (thus the slit width L _R of the illuminated area (46) on the mask (1)).

The present invention uses the method, and the scanning speed is adjusted by adjusting the slit width L _W (and the slit width L _R ) according to the sensitivity p of the photosensitive material on the substrate (10). Substrate (1) while keeping it smaller than the upper limit
The above integrated exposure amount is set to the target exposure amount with high accuracy. The second projection exposure apparatus of the present invention also uses the method, but the sensitivity e of the photosensitive material on the substrate (10) is a preset constant, and the illuminance p of the illumination light is p. Is dealing with the case where it gradually decreases. Therefore, in order to approximate the exposure condition of the substrate (10), the light amount detecting means (1) for detecting the exposure energy on the mounting surface of the substrate (10).
4) is provided, and the slit width L _W on the substrate (10) (and thus the slit width L _R on the mask (1)) is calculated from the equation (7) according to the exposure energy (illuminance) p detected by this. Looking for.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the projection exposure apparatus according to the present invention will be described below with reference to the drawings. In this embodiment, the present invention is applied to the case where a reticle pattern is sequentially exposed on a wafer by a slit scan exposure type projection exposure apparatus. FIG. 1 shows a projection exposure apparatus of the present embodiment. In FIG. 1, a rectangular illumination area (hereinafter, referred to as “slit-shaped illumination area”) by the illumination light EL from the illumination optical system is shown.
The pattern on the reticle 1 is illuminated by this, and the image of the pattern is projected and exposed through the projection optical system 9 onto the wafer 10 coated with the photoresist. When the exposure is performed by the slit scan exposure method, the reticle 1 scans the slit-shaped illumination area of the illumination light EL at a constant speed V _R in the Y direction parallel to the paper surface of FIG. Te, the wafer 10 is a constant velocity V _W in the -Y direction (= β · V _R, β is the projection magnification of the projection optical system 9) is scanned in.

To explain the drive system for the reticle 1 and the wafer 10, the reticle Y drive stage 3 driven in the Y-axis direction is placed on the reticle support 4, and the reticle Y drive stage 3 is used for minute drive. The stage 2 is placed, and the reticle 1 is mounted on the reticle micro-driving stage 2.
Are held by a vacuum chuck or the like. The reticle micro-driving stage 2 is a reticle 1 with a small amount and high precision in the X direction, the Y direction, and the rotation direction (θ direction) perpendicular to the paper surface of FIG. 1 in the plane perpendicular to the optical axis of the projection optical system 9. Position control. A movable mirror 5 is arranged on the reticle micro-driving stage 2, and an interferometer 6 arranged outside
The positions of the reticle micro-driving stage 2 in the X direction, Y direction, and θ direction are constantly monitored. The position information obtained by the interferometer 6 is supplied to the main control system 7.

On the other hand, a wafer Y-axis drive stage 12 driven in the Y-axis direction is placed on the wafer support table 13,
A wafer X-axis drive stage 11 that is driven in the X-axis direction is placed on the wafer, and the wafer 10 is held thereon by vacuum suction via a Zθ-axis drive stage (not shown). The movable mirror 14 is also fixed on the wafer X-axis drive stage 11, and the position of the wafer X-axis drive stage 11 in the X-direction, the Y-direction, and the θ-direction is monitored by the interferometer 15 arranged outside, and the interferometer 15 The position information obtained by is also supplied to the main control system 7. The main control system 7 controls the positioning operation of the wafer Y-axis drive stage 12, the wafer X-axis drive stage 11 and the like via the wafer stage drive device 16 and also controls the reticle Y drive stage 3 via the reticle stage drive device 8. Controls the operation during scanning.

Wafer 1 Wafer 1 on X-axis drive stage 11
A dose monitor 18 including a photomultiplier or a photodiode is arranged near 0, and a photoelectric conversion signal of the dose monitor 18 is supplied to the main control system 7. The height of the light receiving surface of the dose monitor 18 is the wafer 10
The height of the exposure surface is substantially the same as the height of the exposure surface, and the main control system 7 irradiates the wafer 10 by driving the stage on the wafer side to move the dose monitor 18 into the exposure field of the projection optical system 9. It is possible to monitor the actual illuminance p of the illuminating light. The main control system 7 has a keyboard 1
7 is connected, and the operator inputs the sensitivity e of the photoresist coated on the wafer 10 to the main control system 7 via the keyboard 17.

Next, in the illumination optical system of this example, the illumination light emitted from the mercury lamp 31 (for example, a wavelength of 365 nm)
(I line) is condensed by the elliptical mirror 32, converted into a substantially parallel light flux by the input lens 33, and is incident on the fly-eye lens 36. The shutter 34 is arranged near the second focal point of the elliptical mirror 32, and the main control system 7 drives the drive device 35.
The exposure time and the like are controlled by opening and closing the shutter 34 via the.

A large number of secondary light sources are formed on the focal plane on the exit side of the fly-eye lens 36, and the illumination light EL from these large number of secondary light sources passes through the first relay lens 37A and has a uniform illuminance distribution. The pair of movable reticle shading plates 38 and 39 is irradiated. The light that has passed through the opening surrounded by the movable reticle light shielding plates 38 and 39 reaches a pair of fixed reticle blinds 42 and 43 arranged at a position slightly apart from the movable reticle light shielding plates 38 and 39. The width of the slit-shaped illumination area on the reticle 12 in the scanning direction is determined by the opening surrounded by the fixed reticle blinds 42 and 43. The movable reticle shading plate 38 and the fixed reticle blind 42 are connected to the driving device 40, and the movable reticle shading plate 39 and the fixed reticle blind 43 are connected to the driving device 41. Movable reticle shading plate 3
8, 39 because they are moved during one exposure operation, and because they are called fixed reticle blinds 42, 43 because their positions are fixed during the exposure operation.

The main control is performed according to the sensitivity e of the photoresist on the wafer 10, the scanning speed V _R of the reticle 1 (or the scanning speed V _W of the wafer 10), and the illuminance p of the illumination light on the wafer 10. The system 7 controls the positions of the fixed reticle blinds 42 and 43 via the driving devices 40 and 41, respectively, and sets the width of the slit-shaped illumination area on the reticle 2 in the scanning direction. Next, during the exposure operation, the main control system 7
Controls the positions of the movable reticle shading plates 38 and 39 via the driving devices 40 and 41.

FIG. 2 shows the arrangement of the movable reticle shading plates 38, 39 and the fixed reticle blinds 42, 43 along the optical axis AX of the illumination optical system. In FIG. 2, the scanning direction (Y) of the reticle 1 of FIG. The direction conjugate with the (direction) is the Y1 direction, and the direction conjugate with the non-scanning direction (X direction) is the X1 direction. Then, one movable reticle shading plate 38 is integrally formed with a blade 38y having an edge perpendicular to the Y1 direction and a blade 38x having an edge perpendicular to the X1 direction, and the other movable reticle shading plate 39 is formed to the Y1 direction. The blade 39y having an edge perpendicular to the direction and the blade 39x having an edge perpendicular to the X1 direction are integrally formed.
Blades 38y, 39y having edges perpendicular to the Y1 direction
And blades 38x, 39 having edges perpendicular to the X1 direction
The x is stepped in the optical axis AX direction so as not to interfere with each other.

The movable reticle shading plates 38 and 39 are supported so as to be movable in the X1 direction and the Y1 direction, respectively, and the illumination area on the reticle 12 in FIG. 2 is controlled by the opening surrounded by the blades 38y and 39y. Due to the opening limited in the Y direction and surrounded by the vanes 38x and 39x, FIG.
The illumination area on the reticle 12 is limited to the X direction. Similarly, one fixed reticle blind 42 includes a knife edge 42y having an edge perpendicular to the Y1 direction, and X1.
The fixed reticle blind 43 is an L-shaped member in which a knife edge 42x having an edge perpendicular to the direction is integrated, and the other fixed reticle blind 43 has a knife edge 43y having an edge perpendicular to the Y1 direction and an edge perpendicular to the X1 direction. It is an L-shaped member that integrates the knife edge 43x that it has. The fixed reticle blinds 42 and 43 are arranged at positions slightly deviated in the optical axis AX direction, and can freely move in the X1 direction and the Y1 direction with respect to each other.

Returning to FIG. 1, the movable reticle shading plate 38 is shown.
Of the light that has passed through the opening surrounded by and 39, the light that has passed through the opening surrounded by the fixed reticle blinds 42 and 43 illuminates the reticle 1. Then, the illumination light EL that has passed through the openings of the fixed reticle blinds 42 and 43.
Illuminates the slit-shaped illumination area 46 on the reticle 1 with a uniform illuminance via the second relay lens 37B, the mirror 44, and the main condenser lens 45. Strictly speaking,
The illumination area 46 is an area set by the openings of the fixed reticle blinds 42 and 43.
The illumination light EL is provided only in the area where the illumination visual field set by the opening surrounded by the movable reticle shading plates 38 and 39 overlaps.
Is irradiated. The pattern of the reticle 1 is projected and exposed onto a slit-shaped exposure area 47 that is conjugate with the illumination area 46 and the projection optical system 9.

In this case, the movable reticle shading plates 38 and 3
In FIG. 9, the blades 38y and 39y (see FIG. 2) that set the illumination field in the scanning direction on the reticle 12 are the reticle 1
Blades 38x and 39 arranged on the conjugate surface with the pattern formation surface of the reticle 1 and setting the illumination field in the non-scanning direction on the reticle 1.
x (see FIG. 2) is the first relay lens 3 from its conjugate plane.
It is located on the surface slightly defocused to the 7A side.
Further, the fixed reticle blinds 42 and 43 are arranged on a surface defocused from the conjugate surface of the reticle 1 with the pattern forming surface toward the second relay lens 37B by a predetermined distance.

Next, an example of the operation when performing exposure by the slit scan exposure system in this example will be described with reference to FIG. FIG. 3 is a plan view of the reticle 1 of this example, and an image of the pattern in the pattern forming area PA inside the reticle 1 is exposed on the wafer 10 in FIG. In addition, the pattern area P
A is surrounded by a light-shielding band (forbidden band) 48 having a predetermined width. On the reticle 1, a slit-shaped illumination area 46 set by the fixed reticle blinds 42 and 43 of FIG.
The illumination light EL is applied to a region where the illumination visual field 49 set by the movable reticle light shielding plates 38 and 39 in FIG. When the edges on both sides of the illumination area 46 in the scanning direction (Y direction) are within the pattern area PA, the illumination field 4 is included.
The edges on both sides in the Y direction of 9 are outside the edges on both sides in the Y direction of the illumination region 46. Further, both edges of the illumination visual field 49 in the X direction are inside the light shielding band 48, and both edges of the illumination region 46 in the X direction are outside the light shielding band 48.

When one edge of the illumination area 46 in the Y direction goes out of the light-shielding band 48 at the start or end of scanning, the movable reticle light-shielding plate 38 or 39 shown in FIG. By retaining one edge of 49 within the light-shielding band 48, it is possible to prevent unnecessary patterns outside the light-shielding band 48 from being projected onto the wafer 10. That is, the width (slit width) L _R of the illumination area 46 in the Y direction is fixed during one scanning exposure, and the reticle 1 is scanned with respect to the illumination area 46 in the Y direction at the speed V _R. .

FIG. 4 shows a shot area SA on the wafer 10 corresponding to FIG. 3, and the pattern image in the illumination area 46 in the pattern area PA on the reticle 1 in FIG. 3 is on the shot area SA in FIG. Is projected in the slit-shaped exposure area 47. Width of exposure area 47 in the Y direction (slit width)
Is L _W and the width in the X direction is D, and the wafer 10 is scanned in the −Y direction with respect to the exposure region 47 at the speed V _W. In this embodiment, the fixed reticle blinds 42 and 43 of FIG. 2 are operated according to the sensitivity e of the photoresist on the wafer 10 to operate the slit width L _W of the exposure area 47 on the wafer 10 (and the illumination on the reticle 1). The slit width L _R of the area 46 is set. A specific example will be described below.

For example, the projection magnification β of the projection optical system 9 is 1 /
5, the slit width L _W of the exposure area 47 on the wafer 10 is 1
0 [mm], illuminance p of illumination light on the exposed surface of the wafer 10
Is 800 [mW / cm ² ], scanning speed V _{R of} reticle 1
Of maximum value V _max of 250 [mm / sec] for wafer 10
The sensitivity e of the above photoresist is 200 [mJ / cm ² ]
Consider the case.

At this time, the optimum exposure time t at one point on the wafer 10, which is determined from the illuminance p of the illumination light and the sensitivity e of the photoresist, is as follows. t = e / p = 200/800 = 0.25 [sec] (8) In this case, the scanning speed V _R of the reticle 1 is as follows from the equation (6). V _R = L _W · p / (β · e) = 5 · 10 / 0.25 = 200 [mm / sec] (9) In addition, from the equation (6), when V _R > V _max The range of the sensitivity e is as follows.

E <L _W · p / (β · V _max ) = 5 × 10 × 8
00/250 = 160 [mJ / cm ² ] (10) Therefore, for a high-sensitivity photoresist whose sensitivity e is smaller than 160 [mJ / cm ² ], the scanning speed V _{R of the} reticle exceeds the maximum speed V _max. I will end up. Therefore, for example, when exposing a photoresist having a sensitivity e of 100 [mJ / cm ² ], the scanning speed V _{R of the} reticle is 250 [mm / s].
ec], the slit width L _W of the exposure region 10 on the wafer 10 is uniquely determined from the equation (6), and is as follows.

L_W= V_R・ Β ・ e / p = (250/5)
(100/800) = 6.25 [mm] (11) Also, the scanning speed V of the reticle._RBe as large as possible
Is more advantageous in terms of throughput because it shortens the processing time.
From the reticle scanning speed V_RThe maximum speed V _max Solid
The slit width L_WOnly variable, photoregis
It is also possible to correspond to the sensitivity e of the switch. Pickpocket in this case
Width L_WIs as follows from equation (6).

L _W = V _max βe / p (12) Next, in this example, the illuminance p on the exposed surface of the wafer 10 may gradually decrease due to the change over time of the mercury lamp 31.
Therefore, in order to cope with such a change with time, before performing exposure on each wafer, the dose monitor 1 shown in FIG.
8 may be moved to the exposure surface of the projection optical system 9 to actually measure the illuminance p of the illumination light on the exposure surface of the wafer. And
Obtains the slit width L _W by substituting thus actually measured illuminance p in (12), its the slit width L _W by moving the fixed reticle blind 42 and 43 in FIG. 1
To set. This improves control accuracy when the integrated exposure amount on the wafer is adjusted to the target exposure amount (photoresist sensitivity).

In the above-described embodiment, the width L of the slit-shaped exposure area 47 on the wafer 10 in the scanning direction is fixed by the fixed reticle blinds 42 and 43 arranged near the surface of the illumination optical system which is conjugate with the reticle 1. _W is set. However, as shown in FIG. 5, using fixed reticle blinds 50 and 51 arranged on the lower surface of the reticle 1,
The width of the slit-shaped exposure area 47 on the wafer 10 in the scanning direction may be set. In FIG. 5 in which parts corresponding to those in FIG. 1 are designated by the same reference numerals, two L-shaped parts (only the cross section is shown in FIG. 5) inside the stage on the reticle side and on the lower surface of the surface on which the reticle 1 is scanned. ) Fixed reticle blinds 50 and 51 are movably arranged, and the fixed reticle blinds 50 and 51 substantially set the illumination area on the reticle 1.

Further, although the light of the mercury lamp is used as the illumination light in the above-mentioned embodiment, the present invention is directly applied to the case where the harmonics of the excimer laser light and the argon laser light are used as the illumination light. can do. As described above, the present invention is not limited to the above-described embodiments, and various configurations can be adopted without departing from the gist of the present invention.

[0041]

According to the first projection exposure apparatus of the present invention,
Since the width of the illumination area on the mask in the scanning direction is substantially changed according to the sensitivity of the photosensitive material, the scanning speed of the stage is kept below the upper limit and the control accuracy of the integrated exposure amount to the substrate is improved. There is an advantage that accuracy can be maintained.

Further, according to the second projection exposure apparatus of the present invention, the exposure energy of the illumination light on the mounting surface of the substrate is measured, and the width of the illumination area on the mask in the scanning direction is measured according to the exposure energy. Therefore, even if the illuminance of the illumination light changes with time, there is an advantage that the control accuracy of the integrated exposure amount with respect to the substrate can be maintained with high accuracy.

[Brief description of drawings]

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

FIG. 2 is a perspective view showing a configuration of movable reticle light-shielding plates 38, 39 and fixed reticle blinds 42, 43 in FIG.

FIG. 3 is a plan view showing an illumination area 46 and an illumination field 49 on the reticle of the embodiment.

FIG. 4 is a plan view showing an exposure area on a wafer of an example.

5 is a configuration diagram of a main part showing a modified example of the fixed reticle blinds 42 and 43 of FIG.

[Explanation of symbols]

 1 reticle 3 reticle Y drive stage 4 reticle support 7 main control system 9 projection optical system 10 wafer 12 wafer Y-axis drive stage 13 wafer support 17 keyboard 18 dose monitor 31 mercury lamp 36 fly-eye lens 38, 39 movable reticle light shielding Plates 42, 43 Fixed reticle blind 45 Condenser lens 46 Illumination area 48 Exposure area 49 Illumination field of view

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location G03F 7/22 H 9122-2H

Claims (2)

[Claims] 1. An illumination optical system for illuminating an illumination area on a mask with illumination light; a projection optical system for projecting an image of the pattern of the mask in the illumination area onto a substrate coated with a photosensitive material; A mask-side stage that scans the mask in a predetermined direction with respect to an illumination area, and a substrate-side stage that scans the substrate in a predetermined direction with respect to an exposure area that is conjugate with the illumination area in synchronization with the scanning of the mask. A scanning projection exposure apparatus which sequentially exposes an image of the pattern of the mask onto the substrate, a sensitivity input means for inputting the sensitivity of the photosensitive material applied to the substrate, and the mask by the illumination light. A variable field stop that sets the upper illumination area to a predetermined shape, and sets the width of the illumination area of the predetermined shape in the scanning direction to an arbitrary width within a predetermined range, and a light amount that detects the exposure energy of the illumination light. Detection means, the sensitivity of the photosensitive material input by the sensitivity input means,
The width of the illumination area on the mask in the scanning direction is obtained from the exposure energy of the illumination light detected by the light amount detection means and the scanning speed of the mask by the mask-side stage that is equal to or less than a predetermined upper limit value. A projection exposure apparatus comprising: a calculation unit; and a control unit that sets the width of the illumination area obtained by the calculation unit through the variable field stop. 2. An illumination optical system for illuminating an illumination area on a mask with illumination light, a projection optical system for projecting an image of the pattern of the mask in the illumination area onto a substrate coated with a photosensitive material, and A mask-side stage that scans the mask in a predetermined direction with respect to an illumination area, and a substrate-side stage that scans the substrate in a predetermined direction with respect to an exposure area that is conjugate with the illumination area in synchronization with the scanning of the mask. In the scanning projection exposure apparatus, which sequentially exposes the image of the pattern of the mask on the substrate, the illumination area on the mask by the illumination light is set to a predetermined shape, and the illumination area of the predetermined shape is A variable field diaphragm that sets the width in the scanning direction to an arbitrary width within a predetermined range, a light amount detection unit that detects the exposure energy of the illumination light on the mounting surface of the substrate, and a preset amount of the photosensitive material. From the sensitivity, the scanning speed of the mask by the mask-side stage below a predetermined upper limit, and the exposure energy of the illumination light detected by the light amount detecting means, the width of the illumination area on the mask in the scanning direction. A projection exposure apparatus comprising: a calculation unit that calculates the width of the illumination area and a control unit that sets the width of the illumination region calculated by the calculation unit via the variable field stop.