JPH06177007A - Projection aligner - Google Patents

Abstract

PURPOSE:To realize the long service-life of a blind filter and improve an exposing throughput when resolution or focusing depth is not necessitated by applying a master drawing substrate with obliquely incident illumination to expose it to a minimum as necessary with high resolution and large focusing depth while placing a pupil filter at a projection lens aperture diaphragm position and exposing it by replacing the pupil filter with only the aperture diaphragm when the resolution or focusing depth is not necessitated so much. CONSTITUTION:An aperture limiting plate having a specified optical thickness and light transmissivity for limiting the size of the aperture and a pupil filter 25, that is provided with a transmissivity adjusting thin film 28 and has the same optical thickness as that of the aperture limiting plate, are selectively fixed at the aperture diaphragm position of a projection lens 11 wile the lens 11 is still fitted in a projection aligner.

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 for projecting and transferring a fine pattern of a semiconductor integrated circuit or the like on an original substrate onto a substrate to be exposed such as a semiconductor.

[0002]

2. Description of the Related Art A projection exposure method using short-wavelength visible light or far-ultraviolet rays is used for forming a fine pattern of a semiconductor integrated circuit or the like on a substrate to be exposed such as a semiconductor wafer easily, at high speed and at low cost. ing. FIG. 6 shows an optical system of a conventional projection exposure apparatus described in “LSI Design and Manufacturing Technology”, page 248, published by Denki Shoin Co., Ltd. This will be roughly described with reference to FIG. 1. Light emitted from the mercury lamp 1 is condensed by the elliptic concave mirror 2 and the collimator lens 3, passes through the filter 4 for monochromaticity, and enters the fly-eye lens 5. A first reflecting mirror 6 is provided between the mercury lamp 1 and the collimator lens 3 to convert light from the lamp into a direction substantially orthogonal to the light source optical axis and to transmit heat rays to the back side. The fly-eye lens 5 is composed of an assembly of many small-diameter lenses, and the light emitted from each lens is the second reflecting mirror 7.
Is reflected by the condenser lens 8 and is condensed by the condenser lens 8 to illuminate the reticle 9 which is the original drawing substrate.
This can improve the uniformity of illumination. Whereas the mercury lamp 1 is the original light source (primary light source),
The emission side of the fly-eye lens 5 serves as a substantial emission source of light that illuminates the reticle 9, and is called a secondary light source.
The second reflecting mirror 7 is for changing the direction of the light ray again. The reticle 9 is provided on a reticle holding table 10 on which a pattern of a fine pattern such as a semiconductor integrated circuit is formed, and when illuminated by the light emitted from the condenser lens system 8, the fine pattern is projected onto the projection lens 11. Is transferred onto the wafer 12, which is a substrate to be exposed, coated with a resist. The projection lens 11 is made by combining a large number of lenses to eliminate various aberrations, but basically, the reticle 9 is used.
Side and the wafer 12 side are divided into two blocks, and an aperture stop 13 is installed between them. Light emitted from an arbitrary point on the reticle 9 passes through the lens group on the reticle 9 side, then becomes substantially parallel, passes through the aperture stop 13, and enters the lens group on the wafer 12 side. Then, the light is focused by the lens group on the wafer 12 side, and focused and imaged at one point at the resist position on the surface of the wafer 12. The wafer 12 is for adjusting and determining the position and the height with respect to the projection lens 11,
It is installed on the X moving stage 14, the Y moving stage 15, the Z moving stage 16, and the rotating stage 17. The resolution of the pattern transferred onto the wafer 12 is determined by whether or not the diffracted light due to the pattern existing on the reticle 9 can be taken into the aperture stop 13, and the highest resolution is 0 order diffracted light and 1 It is largely determined whether the second-order diffracted light can be taken into the aperture stop 13. The direction in which the first-order and higher-order diffracted light travels is determined by the cycle of the pattern and the fineness of the pattern. Therefore, when the reticle 9 is illuminated vertically, the diffracted light of the first order or more advances toward the outer side of the projection lens 11 when the pattern is fine. Therefore, the larger the aperture of the aperture stop 13, the more diffracted light having a fine pattern can be captured, resulting in high resolution.

By the way, Japanese Patent Application Nos. 3-99822 and 3-157401 already filed by the same applicant.
For example, the reticle is obliquely illuminated so that the 0th-order diffracted light of the pattern existing on the reticle passes near the outer periphery of the aperture stop in the oblique illumination light traveling direction, and the 1st-order diffracted light on one side is opposite to the aperture stop. If the light passes through the outer periphery of the reticle, the reticle is illuminated vertically, and the first-order diffracted light on both sides of the pattern existing on the reticle passes through the aperture stop, compared to the direction of the incident light. It is disclosed that a very high resolution can be obtained because even the first-order diffracted light that spreads outward at an angle of about twice can be captured. In addition, when the method of illuminating the reticle obliquely is adopted as described above, a transfer image is formed only by the 0th-order diffracted light and the 1st-order diffracted light on one side. There is an advantage that the depth of focus at the time of transferring a fine pattern is significantly improved as compared with the case of a total of three light fluxes of the first-order diffracted light. In order to illuminate the reticle obliquely, as disclosed in Japanese Patent Application No. 59-212169, the light from the center of the fly-eye lens 5 on the exit side is cut off and the light from the periphery is illuminated. Good. That is,
Illumination may be performed by an annular or multipoint secondary light source. However, if the reticle 9 is simply illuminated at an angle, the reticle 9
The 1st-order diffracted light due to the pattern depending on the above can be taken into the aperture stop only for one side, whereas the 0-th order diffracted light that travels straight passes through the aperture stop. As a result, the 0th-order diffracted light becomes too much, and the contrast of the image of the fine pattern formed at the resist position decreases. For the purpose of compensating for this drawback, Japanese Patent Application Nos. 3-135317 and 3-157401, etc., adjust the amount of 0th-order diffracted light to an appropriate amount at the time of oblique illumination. Disclosed is a projection exposure apparatus and method having "a projection lens aperture whose transmittance is adjusted around the aperture".

[0004]

However, the aperture stop 1
When the "pupil filter", which is the "projection lens aperture whose transmittance is adjusted", is installed at the position of 3, the resolution becomes high and the depth of focus becomes deep, but the following problems occur. The exposure light passing through the projection lens and reaching the substrate to be exposed is reduced by the amount that the transmittance is limited by the pupil filter. Therefore, the exposure time increases correspondingly, and the throughput decreases. The light that is limited by the pupil filter and cannot pass through the aperture stop position is either absorbed by the pupil filter or reflected by the pupil filter, depending on the type of the pupil filter.
The reflected light will eventually be absorbed somewhere inside the projection lens, or will be reflected several times somewhere and then will pass through the aperture stop of the projection lens again and reach the substrate to be exposed. When absorbed by the pupil filter, the absorbed energy is converted into heat, causing the temperature of the pupil filter to rise. If it is absorbed somewhere inside the projection lens, it causes a temperature rise in that part. If the temperature rises anywhere in the projection lens, including the pupil filter, the projection lens will be distorted and the lens dimensions and interlens dimensions will change. It causes dimensional changes and deterioration of uniformity in the exposure field. Also,
When a projection lens with a pupil filter is used for a long time, the thin film forming the pupil filter deteriorates due to long-time irradiation of exposure light rays, and eventually the film peels off and the peeling pieces adhere to the projection lens members above and below the filter. Since these deposits cause transfer defects during exposure, they must be carefully monitored to prevent them from depositing. However, once such peeling pieces adhere to the projection lens member, they cannot be removed unless the projection lens is disassembled and overhauled. On the other hand, when the light is reflected by the pupil filter surface, the light that reaches the pupil filter surface again after passing through the pupil filter surface after being reflected several times and then reaching the substrate to be exposed is noisy in the light rays forming the pattern. Since it is superposed as light, it causes deterioration of resolution, deterioration of exposure contrast, and the like. When a glass material with some translucency is used as a pupil filter for limiting the transmittance in a projection lens designed to be a simple aperture plate as an aperture stop, the optical path length is changed and the resolution is impaired. . When a certain glass material is used as a pupil filter for limiting the transmittance, a projection lens designed by correcting the lens aberration in consideration of the existence of the glass material must be used.

In order to deal with the above three problems,
Accordingly, when transferring a large pattern for which high resolution is not required, exposure is performed without limiting the transmittance of the aperture stop. Accordingly, the frequency of use of the pupil filter that limits the transmittance is reduced. Also, the pupil filter film is replaced before it is deteriorated and peeled off. Corresponding to the above, a projection lens which is designed by correcting the lens aberration in consideration of the existence of a glass material to be inserted as a pupil filter for limiting the transmittance in advance is used. Is effective. The method of exposing without limiting the transmissivity of the aperture stop when transferring a large pattern that does not require high resolution, as a means to solve the problem, reduces the frequency of use of the pupil filter that restricts the transmissivity. At the same time, it becomes a countermeasure against the problem.

Therefore, the present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to illuminate the original drawing substrate with oblique incidence and place a pupil filter at the projection lens aperture stop position. Extend the life of the pupil filter by performing exposure with high resolution and large depth of focus to the minimum required, and replacing the pupil filter with a simple aperture stop for exposure when resolution or depth of focus is not so required. It is an object of the present invention to provide a projection exposure apparatus capable of improving the exposure throughput when resolution and depth of focus are not required.

[0007]

In order to achieve the above object, the present invention provides a projection exposure apparatus which projects and transfers a pattern on an original drawing substrate onto a substrate to be exposed through a projection lens. At least 1 having thickness and translucency
Two aperture limiting plates, and at least one pupil filter having a transmittance adjusting thin film formed thereon and having the same optical thickness as the aperture limiting plate. The aperture limiting plate and the pupil filter are connected to the projection lens. Is selectively installed at the aperture stop position of the projection lens while being installed in the projection exposure apparatus.

[0008]

In the present invention, the translucent aperture limiting plate does not limit the transmissivity of the aperture stop and is used when transferring a large pattern that does not require high resolution, and a pupil filter that limits the transmissivity. Use less frequently. The pupil filter is used when performing exposure with high resolution and large depth of focus.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in the drawings. FIG. 1 is a perspective view of a projection lens and a pupil filter, FIG. 2 is a cross-sectional view of a main part, and FIGS. 3A and 3B are aperture limiting plates that limit only the size of the aperture without limiting the transmittance, and It is a perspective view of the pupil filter which limits a ratio. In the figure, the same components as those of the conventional device shown in FIG. 6 are designated by the same reference numerals. In these figures, a projection lens 11 arranged between a reticle and a wafer which is a substrate to be exposed to form a fine pattern of the reticle on the wafer includes a reticle side lens group 21a (FIG. 6),
It is provided with a cylindrical body 22 coaxially with the wafer side lens group 21b (FIG. 6). A long hole 23 that is long in the circumferential direction is formed on a part of the peripheral surface of the cylindrical body 22 at a portion corresponding to the reticle side lens group 21a and the wafer side lens group 21b, that is, a position where an aperture stop is installed. The aperture limiting plate 24 is formed so as to transmit light from the elongated hole 23 and limits only the size of the aperture without limiting the transmittance, and has the same optical thickness as the aperture limiting plate 24. The pupil filter 25 for limiting the transmittance can be selectively inserted. In this case, the aperture limiting plate 24 is used when transferring a large pattern for which high resolution is not required, and the pupil filter 2
5 is used when exposure with high resolution and large depth of focus is performed.

The aperture limiting plate 24 is made of a transparent glass material such as synthetic quartz, fused quartz, synthetic fluorite, and fused fluorite, and the surface other than the opening 24a is shown in FIG. , Covered with a light shielding film 26 as shown in FIG. It goes without saying that the light shielding film 26 may be made of any material as long as it shields the exposure light beam.

The pupil filter 25 is made of a glass material similar to the aperture limiting plate 24 and has a light-transmitting plane plate 27.
And a light-shielding film 26 and a transmissive film 28 for adjusting the transmittance, which are formed on the flat plate 27. Permeable membrane 2
No. 8 is a ring-shaped material formed in the opening 25a and can be any material as long as it can impart a predetermined transmittance to the exposure light beam. For example, a thin film of chromium, a thin film of chromium oxide, or a fluoride film. It is a multilayer thin film of magnesium and zinc sulfide, etc.

Here, the aperture limiting plate 24 and the pupil filter 2
The optical thickness of 5 does not mean the absolute value of these simple thicknesses, but means the thickness considering the refractive indexes of the aperture limiting plate 24 and the plane plate 27. The total phase angle Φ (radian) that changes while the light beam of wavelength λ passes through the entire thickness including the adhesion film is 2
The value obtained by dividing by π and multiplying by the wavelength λ is the optical thickness t (= Φ · λ / 2π) here. Although the expression "the transmittance is not limited" is used in the above description, a slight attenuation of the transmission amount cannot be avoided by any aperture limiting plate 24 and flat plate 27 made of any glass material. It means that the transmittance is not lowered. The same applies to the following description.

In FIG. 2, a vacuum suction plate 31 having a vacuum suction hole (or vacuum suction groove) 30 is disposed inside the cylindrical body 22 at the aperture stop position.
An aperture limiting plate 2 which is selectively inserted from above the long hole 23.
4 or pupil filter 25 is installed and configured to be vacuum-adsorbed. Therefore, the vacuum suction hole 30 is connected to a vacuum pump (not shown) via the tube 33. Incidentally, 34 is a piping component for connecting the tube 33 to the vacuum suction plate 31, and this piping component 34 is screwed into the vacuum suction plate 31 via a packing 35. 36
Is a lid member for airtightly closing the lower end opening of the vacuum suction hole 30, and 37 is a stopper for determining the position in the insertion depth direction when the aperture limiting plate 24 or the pupil filter 25 is inserted. Although the vacuum suction plate 31 is a simple parallel plate in the drawing, it may be a component that also has a function of holding the adjacent lenses in the projection lens 11, and the shape is arbitrary. When vacuum suction is performed, the surface of the aperture limiting plate 24 with the light shielding film 26 or the surface of the pupil filter 25 with the transmission film 28 is positioned at the original aperture stop position. Vacuum suction plate 3
Although the material of No. 1 is arbitrary, a material such as ceramic, which is unlikely to cause protrusion during the production of the vacuum suction surface, is suitable.

Although the method of attaching the vacuum suction plate 31 to the inside of the cylindrical body 22 is arbitrary, the attachment surface is used as an assembly reference plane, and the vacuum suction plate 31 has a predetermined upper surface and lower surface which are parallel to each other and have a certain flatness. Opening limit plate 24
Alternatively, the pupil filter 25 can be arbitrarily replaced and installed at a position in the predetermined optical axis direction.

In FIG. 2, the vacuum suction plate 31 is directly provided in the cylindrical body 22.
However, it is not always easy to provide a highly accurate mounting surface for the vacuum suction plate 31 inside a long cylindrical body. The mounting surface of the vacuum suction plate 31 may be provided on a component for holding each lens, a component serving as a spacer between the lenses, and the like inside the cylindrical body 22. On the contrary, if it is possible to perform accurate processing, without providing the vacuum suction plate 31 separately,
It is obvious that the vacuum suction hole 30 or the vacuum suction groove may be directly provided in the cylindrical body 22.

Since the transmission film 28 of the pupil filter 25 has a thickness, the optical optical path length depending on the film thickness is the projection lens 1.
There may be a problem in considering the aberration of 1. In that case, the optical thickness of the aperture limiting plate 24 that limits only the size of the opening without the transmission film is the same as that of the flat plate 27 with the transmission film 28. The thickness of the aperture limiting plate 24 is determined in advance. By adding a transmissive film having the same optical optical path length as that of the transmissive film 28 of the pupil filter 25 to the aperture restricting plate 24 that restricts only the size of the aperture, the pupil filter 25 and the aperture restricting plate 24 are optically coupled. The target thicknesses may be the same. In any case, as shown in FIGS. 1 and 2, when the pupil filter 25 or the aperture limiting plate 24 is attached to the vacuum suction plate 31 inside the cylindrical body 22 of the projection lens 11 by suction, To be able to exert the initial lens function.

Aperture limiting plate 2 inserted in the projection lens 11
4 or a position in a direction parallel to the surface of the pupil filter 25 is positioned by providing a guide or pressing against a stopper 37. Moreover, you may press in one direction with a spring. In FIG. 2, the stopper 37 that positions only in the insertion depth direction.
However, if a similar stopper is provided in the direction orthogonal to the insertion direction, the position can be uniquely determined.

FIGS. 4A to 4H are perspective views showing other embodiments of the pupil filter for limiting the transmittance.
(A) is an example in which a multi-point transmissive film 28 is provided in the opening 25a, and (b) is a transmissive film 28a, 28b having different transmittances T ₁ , T _{2 in} the opening 25a. An example of concentric circles, (c) in the figure, the transmissive film 28a having the transmissivity T ₁ is provided in a multipoint manner in the opening 25a, and the transmissivity T ₂ is also provided outside thereof.
An example in which the permeable membrane 28b is provided in an annular shape, (d) is a multi-point permeable membrane 28a (transmittance T ₁ ) provided in the opening 25a, and the permeable membrane 28b (transmittance) is also provided outside thereof. T ₂ ) is provided, the transmittance T ₃ is also shown in the center of FIG.
An example in which a permeable film 28c having a transmittance of T ₃ is provided in the central portion of FIG. 6C, and an example in which a transparent film 28c having a transmittance T ₃ is provided in the central portion of FIG. Also, an example in which a transmissive film 28c having a transmissivity T ₃ is provided, and (h) is a transmissive film 28 in which the transmissivity T is continuously changed as shown in the figure.
Is an example in which is provided. In the figure, the portion with the light shielding film 26 is shown by hatching, and the portion with the transmission film 28 (28a to 28c), that is, the portion where the transmittance is intentionally lowered is shown by hatching or cross hatching. It was

The shape of the transparent film 28 is determined according to the shape of the exit of the fly-eye lens, that is, the shape of the secondary light source. The projection optical system is configured so that the fly-eye lens exit port forms an image at the aperture stop position of the projection lens 11. Therefore, when the fly-eye lens exit is annular, the annular transmittance adjuster (28) of FIG.
Is roughly matched to the size of the annular image at the exit of the fly-eye lens. Further, in the case of FIGS. 4B and 4E, the shape of the portion having the transmittance T ₁ is roughly matched with the size of the annular image at the exit of the fly-eye lens. Of course, it goes without saying that they may be perfectly matched. Even when the fly-eye lens exit has a multipoint shape, a pupil filter provided with a transmission film may be used according to the number, size, and position of the image points. That is, the multi-point transmissive film 28 of FIG. 4A is roughly or completely adjusted to the number, size, and position of multi-point images of the fly-eye lens exit. In addition, FIG.
Also in the cases of (d), (f) and (g), the shape of the portion having the transmittance T ₁ is roughly or completely matched with the size of the multi-point image at the exit of the fly-eye lens. When the fly-eye lens exit has a multi-point shape, it has a ring-shaped transparent film that envelops a multi-point image formed at the aperture stop position.
You may use the pupil filter like (b), FIG.4 (b), (e). The transmittance of the permeable film 28 is arbitrary, and as a special case, T ₁ = T ₂ , T ₂ = T ₃ , T ₁ = T ₃ , T ₁
A pupil filter under the condition of = T ₂ = T ₃ can also be applied.

In the above-mentioned explanatory views (FIGS. 3 and 4), for the sake of clarity, the light-shielding film which limits only the size of the apertures (24a, 25a) without limiting the transmission film 28 or the transmittance of the pupil filter 25. The film 26 includes the aperture limiting plate 24 and the flat plate 27.
It was drawn to exist on the upper surface of. However, the aperture limiting plate 2
4, it may be the lower surface of the plane plate 27. In addition, the light shielding film 2
It is also possible to adopt a structure in which 6 and the transmissive film 28 are sandwiched between two translucent plates. In short, it is sufficient that the projection lens 11 exerts a normal lens function when the transmission film 28 or the light-shielding film 26 that limits only the size of the aperture comes near the original aperture stop position. Since the projection lens 11 exerts a normal lens function, it is necessary to set the optical thickness of the aperture limiting plate 24 or the pupil filter 25 that limits only the size of the aperture and the inclination with respect to the optical axis of the projection lens very accurately. However, the positions of the light-shielding film 26 and the transmission film 28 may be approximately at the original aperture stop positions. Needless to say, it is better to consider that the positions of the light-shielding film 26 and the transmission film 28 are exactly the original aperture stop positions.

The aperture limiting plate 24 and the pupil filter 25 shown in FIGS. 3 and 4 may be prepared in arbitrary types and in arbitrary numbers according to the shape of the light source that the projection exposure apparatus can take. It is also possible to prepare a plurality of sheets of the same type in which the dimensions and transmittance of each part of the pupil filter are changed, or a plurality of aperture limiting plates 24 in which only the aperture size for simply limiting the aperture is changed. Further, the shape and dimensions of the aperture limiting plate 24 and the pupil filter 25 are arbitrary, and they do not have to be rectangular as shown in FIGS. The shape and size may be determined by comprehensively considering the size of the aperture stop, the convenience of attachment to the aperture stop position, the convenience of manufacturing the light shielding film 26 and the transmission film 28, and the like.

By the way, the projection lens 11 is located in the central portion of the projection exposure apparatus, and the projection exposure apparatus is often placed in a chamber that is precisely air-conditioned in order to maintain accuracy. Therefore, it is of course possible to replace the aperture limiting plate 24 and the pupil filter 25 by manual operation, but it is preferable that the replacement is automatically performed by remote operation.

FIG. 5 is a view showing a mechanism for automatically changing the aperture limiting plate 24 and the pupil filter 25 by remote control. The various aperture limiting plates 24 and the pupil filter 25 are connected to the stocker 40.
The aperture limiting plate 24 or the pupil filter 25, which is stored in the computer and is required from the keyboard of the control device 41 such as a personal computer.
By keying in the name or number of the stocker or the name or number of the storage location in the stocker 40, a command is given to the handling mechanism control unit 42 for transportation, and the stocker 40 opens the predetermined aperture limiting plate 24 or pupil filter 25. Fork 43
Is grasped and taken out, inserted into the projection lens 11, and installed on the vacuum suction plate 31. The fork 43 has a suction part and is attached to the lower end of a rod 44, and the rod 44 is attached to an elevating slider 48 provided on a carrier 47 that is movable along a guide 46 so as to be able to move up and down. It is clear that the direction of the loading / unloading port of the stocker 40 and the path and direction of movement of the fork 44 are arbitrary, and there is no need for the directions and paths of arrows a, b, and c in FIG. Stocker 40 in the empty space of the projection exposure apparatus
The stocker 40 and the cylindrical body 2 of the projection lens 11 are installed.
The guide 46 of the fork 44 may be provided between the elongated hole 23 formed in 2 and an appropriate path. At this time, the aperture limiting plate 24 or the pupil filter 25 is handled by the handling mechanism.
2 is positioned in the direction of these surfaces within the required accuracy range, the stopper 37 for positioning in the insertion direction and the stopper in the direction orthogonal to the insertion direction shown in FIG. 2 are unnecessary. Further, it is effective to insert the pupil filter 25 at the aperture stop position of the projection lens 11 in the case of obliquely illuminating the original drawing substrate. Therefore, the projection lens 11
Aperture limiting plate 24 or pupil filter 25 at the aperture stop position of
It is more preferable to interlock the operation of turning on the illumination of the original drawing substrate for switching between the direct incidence illumination and the oblique incidence illumination. At the exit of the fly-eye lens, which is the secondary light source of the projection exposure apparatus,
The shape of the illumination light source can be changed by arbitrarily inserting a plate having a transparent portion or hole such as a circular shape, an annular shape, or a multipoint shape, or sliding or rotating a plate having a plurality of emission ports. Eggplant Then, when the information on the shape of the illumination light source is automatically detected or the information on the shape of the illumination light source is input from the keyboard of the control device 41 such as a personal computer shown in FIG. 5, it is prepared corresponding to the shape of the illumination light source. The type of the aperture limiting plate 24 or the pupil filter 25 placed in the aperture stop position of the projection lens thus selected is displayed on the control device 41 as an image. By doing so, the operator selects and instructs any one of the displayed aperture limiting plate 24 or the pupil filter 25, so that the corresponding aperture limiting plate 24 or the pupil filter 25 is mounted at the aperture stop position. be able to.
If the shape of the illumination light source and the flat plate or pupil filter 25 attached to the aperture stop position of the projection lens 11 are made to correspond one-to-one, and the shape of the illumination light source is automatically detected or key-inputted, the corresponding aperture is automatically obtained. The limiting plate 24 or the pupil filter 25 may be mounted at the aperture stop position. Alternatively, a combination of the actually effective shape and size of the illumination light source and the aperture limiting plate 24 or the pupil filter 25 mounted at the aperture stop position of the projection lens 11 is displayed on the screen of the control device 41. A combination of the shape and size of the illumination light source and the aperture limiting plate 24 or the pupil filter 25 mounted at the aperture stop position of the projection lens 11 is automatically realized by the operator selecting and instructing the combination. You may

[0024]

As described above, according to the projection exposure apparatus of the present invention, an aperture limiting plate that has a predetermined optical thickness and a light transmitting property and limits only the size of the aperture, and the transmittance adjustment. And a pupil filter having the same optical thickness as the aperture limiting plate, and projecting the aperture limiting plate and the pupil filter with the projection lens installed in the projection exposure apparatus. Since the lens is selectively installed at the aperture stop position of the lens, when transferring a large pattern that does not require high resolution, an aperture limiting plate is used to perform exposure with high resolution and large depth of focus. It is possible to reduce the frequency of use of the pupil filter used in some cases. Therefore, the exposure throughput can be remarkably improved when the resolution and the depth of focus are not required. Further, the life of the transmission film of the pupil filter can be extended by the amount that the frequency of use of the pupil filter is reduced. Further, even if the pupil filter deteriorates, the deteriorated pupil filter can be easily replaced with the projection lens attached to the projection exposure apparatus. In the conventional device, when the pupil filter deteriorates, the projection lens needs to be removed, and in some cases, the projection lens needs to be replaced. Therefore, disassembly, reassembly, and readjustment of the entire projection exposure apparatus are required, which requires a great deal of time, labor, and cost. According to the present invention, these problems can be solved at once. Further, the present invention can be applied to a projection exposure apparatus using a mercury lamp as a light source and a projection exposure apparatus using an arbitrary light source such as an excimer laser as an exposure light source. When an excimer laser is used as a light source, exposure energy is applied in a pulsed manner, so that the pupil filter is repeatedly subjected to a large amount of energy, and deterioration of the pupil filter causes a projection exposure apparatus using a mercury lamp as a light source. Faster than. For this reason,
The present invention is particularly effective.

[Brief description of drawings]

FIG. 1 is a perspective view of a projection lens and a pupil filter.

FIG. 2 is a sectional view of a main part of a projection lens.

3A and 3B are perspective views of an aperture limiting plate that limits only the size of an aperture and a pupil filter, respectively.

FIGS. 4A to 4H are perspective views showing other embodiments of the pupil filter.

FIG. 5 is a schematic configuration diagram of an automatic transport mechanism.

FIG. 6 is a diagram showing an optical system of a conventional general projection exposure apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mercury lamp 9 Reticle 11 Projection lens 12 Wafer 13 Aperture stop 24 Aperture limiting plate 25 Pupil filter 26 Light-shielding film 28 Transmission film

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location G03F 7/20 521 9122-2H

Claims (1)

[Claims] 1. A projection exposure apparatus for projecting and transferring a pattern on an original substrate onto a substrate to be exposed through a projection lens, and at least one aperture limiting plate having a predetermined optical thickness and translucency. A thin film for adjusting the transmittance is formed, and at least one pupil filter having the same optical thickness as the aperture limiting plate. The aperture limiting plate and the pupil filter are used as a projection exposure apparatus for the projection lens. A projection exposure apparatus, wherein the projection exposure apparatus is selectively installed at an aperture stop position of a projection lens in an installed state.