WO2003028074A1

WO2003028074A1 - Diaphragm device, projection optical system and projection exposure device, and micro-device producing method

Info

Publication number: WO2003028074A1
Application number: PCT/JP2002/009956
Authority: WO
Inventors: Kenji Tamaoki
Original assignee: Nikon Corporation
Priority date: 2001-09-26
Filing date: 2002-09-26
Publication date: 2003-04-03
Also published as: JPWO2003028074A1

Abstract

This diaphragm device has a plurality of diaphragm blade bases (32) for adjusting the size of the opening (S). This device has a driving mechanism (33) for reciprocally linearly moving the respective diaphragm blade bases (32) in such a manner that, of the outer contours of the diaphragm blade bases (32), an optional point on the contour disposed on the center side of the opening (S) is directed toward substantially the center of the opening (S). This enables the diaphragm device to stand a high frequency of operation and to have a wide diaphragming range.

Description

TECHNICAL FIELD The present invention relates to a diaphragm apparatus, a projection optical system, a projection exposure apparatus, and a microdevice manufacturing method.

The present invention provides a stop device that adjusts the size of an aperture in an optical path, a projection optical system that changes the size of a numerical aperture by an aperture stop, and a mask pattern formed by a light flux based on the numerical aperture defined by the aperture stop. The present invention relates to an exposure apparatus that exposes a substrate, and a method of manufacturing a micro device that is manufactured by exposing a photosensitive substrate with a pattern of a mask. Background art

Conventionally, a mask or reticle (hereinafter, referred to as a reticle) has been used in a lithographic process, which is one of the manufacturing processes for imaging devices such as semiconductor devices, CCDs, liquid crystal display devices, and thin-film magnetic heads. Various exposure apparatuses for transferring a circuit pattern formed on a substrate (eg, a wafer or a glass plate) coated with a resist (photosensitive agent) are used. For example, as an exposure apparatus for semiconductor devices, a reticle pattern is projected onto a wafer using a projection optical system in accordance with the miniaturization of the minimum line width (device rule) of a pattern accompanying the high integration of an integrated circuit in recent years. A reduction projection exposure apparatus that performs reduction transfer is mainly used.

This reduction projection exposure apparatus is a step-and-rebeat type static exposure reduction projection exposure apparatus (so-called stepper) that sequentially transfers a reticle pattern to a plurality of shot areas (exposure areas) on a wafer. The reticle and the wafer are moved one-dimensionally in synchronism with the reticle and the wafer as described in Japanese Patent Application Laid-Open No. 8-16643, etc. A step-and-scan type scanning exposure type exposure apparatus (so-called scan Jung 'stepper) for transferring an image to an area is known.

Due to the demand for finer patterns and higher throughput in recent projection exposure apparatuses, the demand for so-called double exposure, in which a pattern is formed by two exposures in accordance with the pattern accuracy, is increasing remarkably. Usually, when performing this type of double exposure, It is necessary to change the NA (numerical aperture) by using a diaphragm device having two diaphragm blades. FIG. 16 shows an example of a conventional diaphragm device.

The drawing device 50 shown in this figure has a donut-shaped annular part 51 and a metal part 53 having an L-shape in sectional view having a peripheral wall part 52 erected on the outer peripheral part of the annular part 51. And a wheel set 54 rotatably fitted to the peripheral wall portion 52 of the metal piece 53, and a plurality of pieces arranged in a gap between the annular portion 51 and the wheel set 54 of the metal piece 53 (here In this case, 10 diaphragm blades 55 are provided.

Each of the diaphragm blades 5 has a planar shape that forms a part of a ring shape, and a shaft portion (a dowel) (not shown) provided at one end side (counterclockwise direction side) is rotatably supported by the hardware 53. A shaft (dove) (not shown) provided on the other end side (clockwise side) is formed in a wobble 54 along a substantially radial direction of the annular portion 51 (not shown). It is supported so that it can move freely. Further, the aperture blades 55 are annularly mounted so as to be overlapped with each other by being inserted under the adjacent aperture blades 55 on the other end side. The outer contour on the inner diameter side (the center side of the annular portion 51) of each of the aperture blades 55 is formed in a substantially circular arc shape. The opening S is set.

Also, in the above-described diaphragm device 50, the other end side of the diaphragm blade 55 is located at the center side (the inner peripheral side) of the annular portion 51 when the wicker wheel 54 rotates relative to the hardware 53, for example, clockwise. ), The other end of the diaphragm blade 55 rotates toward the outer periphery of the annular portion 51 when rotated counterclockwise, so that the size (aperture) of the opening S is adjusted (changed). You.

However, the conventional diaphragm device as described above has the following problems.

In order to perform double exposure, it is necessary to change the NA frequently, and to achieve this, it is necessary to ensure a high number of operations (for example, 100 times the conventional value) and durability of the aperture device. However, as described above, a method is used in which the diaphragm blades are inserted under the adjacent diaphragm blades on the other end side, so that the diaphragm blades come into contact with and press each other at each operation, which causes dust generation. At the same time, there is a problem that the diaphragm blades are worn out and durability against a high number of operations cannot be obtained. In particular, in the above-described aperture device 50, since the aperture blades 55 are mounted so as to overlap by 4 to 5 sheets over the entire circumference, There was a problem that the contact area between the aperture blades was increased, and the abrasion generated on the aperture blades was larger.

In addition, the dowels of the diaphragm blades that fit with the wheel are fixed to the diaphragm blades by pinching the pins, so it is difficult to withstand high operation times as durability.

On the other hand, the outer contour of the aperture S is an approximate arc synthesized by the arc contours on the inner diameter side (substantially the center side of the aperture S) of the plurality of diaphragm blades, but when the aperture s is set to the maximum diameter, In consideration of the fact that the rotating tip of the diaphragm blade does not cover the opening s, the conventional arc shape is formed so that the error is minimized at the maximum diaphragm diameter. However, such a circular arc profile has a problem that the deviation from the perfect circle in the outer contour (diameter) of the opening s at the minimum aperture diameter increases, that is, the roundness decreases. For this reason, it has been difficult for conventional aperture devices to have a wide adjustable aperture size (aperture range).

In addition, if the accuracy of the aperture diameter of the aperture is reduced as described above, even if the pattern image of the reticle is projected and exposed on the substrate, a fine pattern cannot be accurately formed. There is also a problem that it is difficult to increase the degree of integration of micro devices such as semiconductor devices.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above points, and has a diaphragm device capable of withstanding a high number of operations and securing a wide diaphragm range, a projection optical system having the diaphragm device, and An object of the present invention is to provide a projection exposure apparatus and a micro device manufactured by the projection exposure apparatus. It is another object of the present invention to provide a projection optical system and a projection exposure apparatus capable of accurately projecting a pattern image of a mask onto a substrate, and a method of manufacturing a microphone opening device that achieves high integration. Disclosure of the invention

In order to achieve the above object, the present invention employs the following configuration.

An aperture device according to the present invention is an aperture device (16) having a plurality of aperture blades (32 or 61) for adjusting the size of the aperture (S), wherein the plurality of aperture blades (32 or 61) are provided. 6 1) is linearly moved to any center of the aperture (S 2) at the center side of the aperture (S) toward the approximate center of the aperture, out of the external contour of each diaphragm blade (32 or 61). Sa A driving mechanism (33).

Therefore, in the aperture device of the present invention, for example, the aperture blade (32 or 61) having a shape obtained by dividing the ring shape into a plurality in the circumferential direction has a circumferential gap between the adjacent aperture blade (32 or 61). May be overlapped to such an extent that is not formed. Therefore, even when the diaphragm blades come into contact with each other, the contact area is reduced, and the abrasion that occurs on the diaphragm blades (32 or 61) can be reduced, and it is possible to withstand a high number of operations.

Each of the aperture blades may be arranged with a gap between adjacent aperture blades in a direction substantially parallel to the central axis of the opening. In this case, the contact between the aperture blades can be prevented, and the generation of dust and abrasion due to the contact can be further suppressed to withstand a higher number of operations.

Every one of the aperture blades may be arranged in the same plane substantially perpendicular to the central axis of the opening. In this case, the installation range of the diaphragm blade in the center direction of the opening can be reduced, and the size of the apparatus can be reduced.

Among the outer contours of the aperture blade, the contour on the center side of the opening may be formed to have an arc portion having a predetermined curvature and a straight line portion connected from the arc portion. In this case, irrespective of the size of the aperture diameter, it is possible to prevent a decrease in the roundness of the aperture, thereby making it possible to increase the adjustable aperture range of the aperture and to realize a highly accurate aperture diameter.

The drive mechanism may include a rotating member that rotates around a substantially central axis of the opening as a rotation axis, and a converting member that converts the rotational movement of the rotating member into a linear movement of the plurality of aperture blades. In this case, it is possible to contribute to miniaturization and cost reduction of the device without complicating the structure. A bearing may be mounted on a convex portion that slides by fitting into the fitting groove. In this case, it is possible to withstand a higher number of operations for the linear movement of the aperture blade.

The aperture device may include an aperture blade base that holds the aperture blade so as to be capable of the linear movement. In this case, the aperture range of the adjustable aperture can be widened without increasing the size in a plane, and the amount of rotation of the rotating member can be reduced when adjusting the aperture diameter of the aperture. The time required can be shortened.

The diaphragm blade base may linearly move in the same direction as the direction of movement of the diaphragm blade in accordance with the linear movement of the diaphragm blade. A rotating member that rotates about a substantially central axis of the opening as a rotation axis; and a rotational movement of the rotating member that linearly moves the diaphragm blade, and after the diaphragm blade moves, A link mechanism for linearly moving the aperture blade base. In this case, the aperture range of the adjustable aperture can be widened without increasing the plane by the speed increase by the link mechanism.

The diaphragm blade may be provided with a guide member for guiding the linear movement of the diaphragm blade base. In this case, downsizing of the aperture device and the projection optical system is realized.

The projection optical system according to the present invention is a projection optical system (PL) having an aperture stop (16) capable of changing a numerical aperture, wherein the aperture stop is used as one of claims 1 to 7. A diaphragm device (16) according to (1) is used.

Therefore, in the projection optical system of the present invention, dust generation due to friction of the aperture blades (32 or 61) is reduced, and for example, an adverse effect that occurs when projecting a pattern can be suppressed, and the projection optical system can be used for a long time. The size of the numerical aperture can be made variable throughout.

A projection exposure apparatus according to the present invention is a projection exposure apparatus (1) for projecting and exposing a pattern image of a mask (R) illuminated by a light beam onto a substrate (W). The aperture device (16) is used as an aperture stop that makes the aperture variable.

In this projection exposure apparatus, a pattern image of a mask (R) can be accurately projected and exposed on a substrate (W) for a long period of time with little influence of dust generation.

An aperture stop included in the stop device may be arranged on a pupil plane of the projection optical system. In this case, by making the numerical aperture in the projection optical system accurate and variable over a high number of operations, it is possible to obtain an effect that a fine pattern of a mask can be accurately formed on a substrate.

The method for manufacturing a micro device according to claim 9 or 10, wherein the method for manufacturing a micro device is a method for manufacturing a micro device by exposing a photosensitive substrate (W) with a pattern image of a mask (R). The method includes the steps of: exposing the self-photosensitive substrate with the device pattern image of the mask using the apparatus (1); and developing the exposed photosensitive substrate. Therefore, the microdevice of the present invention can be manufactured with predetermined characteristics and can form a fine pattern, so that high integration can be realized. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a view showing an embodiment of the present invention, and is a schematic configuration diagram of a projection exposure apparatus. FIG. 2 is an external perspective view of a first embodiment of the aperture stop constituting the projection exposure apparatus. FIG. 3 is an external perspective view of a linear guide supporting the aperture blade.

FIG. 4 is a right side view of FIG.

FIG. 5 is a plan view of hardware that forms the aperture stop.

FIG. 6 is a partial cross-sectional view of the aperture stop.

FIG. 7 is a sectional view taken along line AA in FIG.

FIG. 8 is a plan view of the arrow wheel constituting the aperture stop.

FIG. 9 is an exploded perspective view of the aperture stop according to the second embodiment.

FIG. 10 is an external perspective view in which two diaphragm blades are configured to be relatively movable. FIG. 11 is a side sectional view of FIG.

FIG. 12 is an external perspective view of a saddle member constituting the aperture stop.

FIG. 13 is a cross-sectional view in which a linear guide is coupled to an aperture blade.

FIG. 14 is a side sectional view of FIG.

FIG. 15 is a diagram illustrating the operation of the link mechanism.

FIG. 16 is an external perspective view showing an example of a conventional aperture stop.

FIG. 17 is a flowchart illustrating an example of a semiconductor device manufacturing process. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a first embodiment of a stop device, a projection optical system, a projection exposure device, and a micro device of the present invention will be described with reference to FIGS. Here, the aperture device of the present invention is applied to a projection exposure device that exposes a substrate to a reticle pattern via a projection optical system. Here, an example in which the substrate is a wafer for manufacturing semiconductor devices, and the projection exposure apparatus is a scanning projection exposure apparatus that scans and exposes the reticle pattern onto the wafer by synchronously moving the reticle and the wafer. Explanation using I do. In these figures, the same components as those in FIG. 16 shown as a conventional example are denoted by the same reference numerals, and description thereof will be simplified.

FIG. 1 shows a schematic configuration of a projection exposure apparatus 1 according to the present invention. As shown in this figure, in the projection exposure apparatus 1, an ArF excimer laser beam (energy beam) as a light beam having an output wavelength of, for example, 193 nm is emitted from the light source unit 2 to the illumination apparatus side. The light is emitted toward the optical system IU. The main body of the exposure apparatus is housed in a chamber 13 filled or circulated with an inert gas such as nitrogen gas that transmits exposure light, and is controlled so that the temperature and the humidity are kept constant. . The light source unit 2 includes a light source that oscillates pulse light as a substantially parallel light beam narrowed to avoid the oxygen absorption band, and the optical path of the narrowed laser light is located between the illumination optical system IU. There is a beam matching unit (BMU) that matches the beam, a beam shaping optical system that shapes the laser beam into a predetermined cross-sectional shape, and the like.

The laser light incident on the illumination optical system IU is reflected by the reflection mirror 5 and guided to a fly-eye lens 6 as an optical integrator. The fly-eye lens 6 is configured by bundling a large number of lens elements. On the exit surface side of this lens element, a large number of light source images (secondary light sources) corresponding to the number of lens elements constituting the lens element are provided. It is formed. In this example, one fly-eye lens 6 is provided, but a fly-eye lens as a second optical integrator may be provided between the fly-eye lens 6 and the light source unit 2 or the reflection mirror 5. In addition, instead of a fly-eye lens, an internal reflection type aperture-shaped optical member may be used as an optical integrator.

At a position where a number of secondary light sources formed by the fly-eye lens 6 are formed, a turret plate 7 having a predetermined shape and a plurality of aperture stops of a predetermined size is provided. ing. The turret plate 7 is driven to rotate by a motor 8, and one aperture stop is selected according to the pattern of the reticle (mask) R to be transferred onto the wafer (substrate, photosensitive substrate) W, and the illumination optical system IU Inserted in the optical path. The turret plate 7 and the motor 8 constitute a variable aperture stop device for an illumination system.

Light beams from a number of secondary light sources formed by the fly-eye lens 6 pass through a variable aperture stop and are split into two light paths by a beam splitter 9, and the reflected light is converted into an optical path. The illuminance of the illumination light is detected by being guided to the grater sensor 10. The signal S1 corresponding to the detected illuminance is input to the control circuit 40. On the other hand, the transmitted light is driven by the relay lens 11 and the driving mechanism 12a, passes through the field stop 12 that defines the illumination area for the reticle R, passes through the relay lens 13 and is reflected by the reflection mirror 14 The light is condensed by a condenser optical system 15 composed of a plurality of refractive optical elements such as lenses. In the projection exposure apparatus of this embodiment, the optical elements 5, 6, 7, 9, 9, 11, 12, 13, 14, and 15 described above constitute an illumination optical system IU.

The laser light emitted from the illumination optical system IU illuminates the circuit pattern (pattern) formed on the reticle R uniformly in a superimposed manner. Then, an image of the circuit pattern on the reticle R is formed on the wafer W by the projection optical system PL, the resist applied on the wafer W is exposed, and the image of the circuit pattern is transferred onto the wafer W.

The reticle R is held and fixed to the reticle stage 18 by the reticle holder 17 at the object plane of the projection optical system PL. The reticle stage 18 is provided on the base 22 so as to move two-dimensionally along a plane orthogonal to the plane of FIG. The reticle holder 17 is provided with a mirror 21. The laser light from the laser interferometer 20 is reflected by the mirror 21 and enters the laser interferometer 20. Eight positions are measured with high accuracy. The position information is input to the control circuit 40, and the control circuit 40 controls the position of the reticle R by driving the reticle stage drive motor 19 based on the position information.

The projection optical system PL has a configuration in which refractive optical elements such as lenses are all arranged in a plurality of stages, and at least one lens element (for example, a reticle) is used to correct aberrations (magnification errors and the like). A drive mechanism (not shown) that moves the lens element (the lens element closest to R) is provided.

An aperture stop (stop device) 16 is arranged on or near the pupil plane of the projection optical system PL (entrance pupil). In this case, the aperture stop 16 in the projection optical system PL and the variable aperture stop in the illumination optical system IU are arranged at optically conjugate positions. The size of the aperture stop 16 can be changed so as to change the numerical aperture of the projection optical system PL. The details of the aperture stop 16 will be described later.

The wafer W is transferred from the projection optical system PL to the wafer stage 27 by the wafer holder 26. It is located on the image plane. The wafer stage 27 is provided so as to move two-dimensionally along a plane orthogonal to the plane of FIG. A mirror 31 is set on the wafer stage 27, and the laser light from the laser interferometer 30 is reflected by the mirror 31 and enters the laser interferometer 30. Stage 27 position is measured. The position information is input to the control circuit 40, and the control circuit 40 controls the position of the wafer W by driving the wafer stage driving motor 29 based on the position information. An illuminance sensor 28 is provided on the wafer stage 27, and detects illuminance (energy) of exposure light (laser light) applied to the wafer W. The detection signal of the illuminance sensor 28 is output to the control circuit 40.

As shown in FIG. 2, the aperture stop 16 is composed of a plurality of (in this case, 12) aperture blade bases 32, which are arranged equally in an annular shape and form an opening S by the outer contour on the inner diameter side, and And a drive mechanism 33 for linearly moving the diaphragm blade base 32 forward and backward toward the center of the opening S. In the aperture stop 16, an aperture blade base 32 is arranged on or near the pupil plane of the projection optical system PL.

As shown in FIG. 3, each of the aperture blade bases 32 is formed of a material that does not generate outgas (eg, an organic substance) that absorbs exposure light, for example, stainless steel, and has a shape obtained by dividing an annular shape in the circumferential direction. It comprises a ring-shaped portion 34 presenting, and rectangular portions 35, 35 having a substantially rectangular shape in plan view located on both sides in the circumferential direction of the ring-shaped portion 34. Among the outer contours of the annular portion 34, the contour 34a on the center side (ie, the inner diameter side) of the opening S has an arc shape (arc portion) formed with a predetermined curvature. Also, of the outlines of the rectangular portion 35, the outline 35a on the center side of the opening S is a linear shape (linear portion) formed continuously from the outline 34a on the center side of the annular portion 34. ing.

The curvature of the center-side contour 34 a of the ring-shaped portion 34 is set almost in the middle between the maximum curvature and the minimum curvature of the opening S. That is, if the radius of the contour 34a is Ra, the maximum radius of the opening S (maximum aperture diameter) is R MAX, and the minimum radius (minimum aperture diameter) is RMIN, Ra = (R MAX + RMIN) / 2 is set. The circumferential size of the diaphragm blade base 32 is such that when the diaphragm blade base 32 is positioned at the maximum diameter setting position of the opening S, a gap is formed between the circumferentially adjacent diaphragm blade bases 32. When the diaphragm blade base 32 is positioned at the minimum diameter setting position of the opening S, the rectangular The center side contour 35 a overlaps the diaphragm blade base 32 adjacent in the circumferential direction and is set to the minimum size that does not form the outer diameter of the opening S. Therefore, when the opening S is set to the minimum diameter, the contour of the opening S is the center-side contour 34 a of the annular portion 34.

As shown in FIG. 2, the drive mechanism 33 has an L-shape in cross section having a donut-shaped annular portion 51 and a peripheral wall portion 52 erected on the outer peripheral portion of the annular portion 51. Hardware 5 3, a wheel (rotating member) 54 rotatably fitted to the peripheral wall 52 of the metal 5 3, a rotation drive unit (not shown) for rotating the wheel 54, FIGS. As shown in the figure, it is roughly composed of a linear guide (conversion member) 36 that supports the diaphragm blade base 32 and moves linearly. Among the drive mechanisms 33, hardware 53, wickers 54, and linear guides 36 are installed inside the lens barrel of the projection optical system PL, and the rotary drive unit is installed outside the lens barrel, and dust generated by driving Etc. do not affect the projection characteristics of the projection optical system PL.

The linear guide 36 includes a guide portion 37 formed in a linear shape, and a moving body 38 to which the diaphragm blade base 32 is fixed and which moves linearly along the guide portion 37. The moving body 38 is provided with a projection 41 on which a bearing 39 is mounted (see FIG. 4). As shown in Fig. 5, the hardware 53 has guides 37 on the linear guide 36 and grooves 42a and 42b for installing the moving body 38 at equal intervals around the center of the opening S. (At an interval of 30 °) and extend radially from the center. The guide portion 37 is fixed to the grooves 42a and 42b, and the moving body 38 moves along the fixed guide portion 37. The depth of the grooves 42a, 42b is determined by the distance between the adjacent diaphragm blade bases 32, which are fixed to the linear guide 36 when the linear guide 36 is mounted in the grooves 42a, 42b. Are set so as to be spaced from each other in the center direction of the opening S (the direction perpendicular to the paper surface in FIG. 5), that is, the direction substantially parallel to the center axis. Also, every other groove 42 a, 42 b is arranged so that each of the aperture blade bases 32 is disposed in the same plane substantially orthogonal to the center direction (center axis) of the opening S. Formed at different depths.

As shown in FIG. 6, the metal piece 53 is provided with a step 43 for supporting the outer periphery of the wheel 5 4. The wheel 5 4 supported by the step 43 is a metal piece 5 3. A gap 44 for accommodating the diaphragm blade base 32 is formed between the annular portion 51 and the annular portion 51. Although detailed description has been omitted, in practice, the wheel 5 4 is formed by a holding member 4 5 fixed to the metal 5 3. 3, the movement of the opening S in a direction parallel to the center direction is restricted. FIG. 7 is a sectional view taken along line AA in FIG. As shown in this figure, a through hole 47 is formed in the peripheral wall portion 52 of the metal piece 53 at a position substantially at the same height as the wicker wheel 54 to open outward. The through holes 47 are formed at three points at equal intervals (120 ° intervals) in the circumferential direction (see FIG. 5), and each through hole 47 extends over approximately 30 ° in the circumferential direction. It is formed.

As shown in FIG. 8, in the wheel 5, fitting grooves 46 into which the protrusions 41 of the linear guides 36 are slidably fitted via bearings 39 are provided at equal intervals in the circumferential direction (30). At 12 ° intervals). Each fitting groove 46 has a position where the inner diameter side contour of the diaphragm blade base 32 forms the minimum aperture diameter of the opening S and a position of the convex portion 41, and the inner diameter side contour of the aperture blade base 32 has the opening S The projection 41 is formed in a linear shape that is connected to the position of the convex portion 41 when forming the maximum aperture diameter at a predetermined angle (for example, 20 °) in the circumferential direction. More specifically, each of the fitting grooves 46 is such that the position of the convex portion 41 when forming the maximum aperture diameter of the opening S is different from the position of the convex portion 41 when forming the minimum aperture diameter of the opening S. It is formed in a linear shape located clockwise. As a lubricant used between the guide portion 37 and the moving body 38 and for the bearing 39, a fluorine-based lubricant that generates little gas is used. In addition, the protrusions 41 themselves are also formed of a fluorine-based resin.

Further, as shown in FIG. 7, three levers 48 are provided on the outer periphery of the arrow wheel 54 at positions corresponding to the positions of the through holes 47 of the hardware 53. The above-described rotation drive unit rotates the arrow wheel 54 through the lever 48.

First, the operation of the aperture stop 16 in the projection exposure apparatus 1 having the above configuration will be described. When the rotation drive unit drives the rotation wheel 54 around the central axis of the opening S with respect to the hardware 53, for example, clockwise in FIG. 2, the protrusion fits into the fitting groove 46 of the rotation wheel 54. The part 41 moves toward the center of the opening S when the moving body 38 is guided by the guide part 37. In other words, the rotational movement of the arrow wheel 54 is converted into a linear movement by the linear guide 36, and the convex portion 41 moves toward the center of the opening S. Due to the movement of the convex portion 41, the aperture blade base 32 opens any point of the center side contours 34a and 35a with a gap between the adjacent aperture blade base 32. The beam moves linearly toward the approximate center of S, whereby the aperture diameter of the aperture S is reduced. With the conventional diaphragm device, the diaphragm Whereas any point on the inner contour of the blade moves spirally, the aperture device of the present embodiment differs from the conventional one in that any point on the inner contour 34 a and 35 a of the aperture blade moves linearly. The configuration of the diaphragm device of this embodiment is different from that of the diaphragm device of the present embodiment.

On the other hand, by rotating the whirler 54 with respect to the hardware 53 by driving the rotation drive unit, the protrusion 41 is rotated with respect to the center of the opening S in the reverse operation by rotating counterclockwise in FIG. As a result, the aperture diameter of the aperture S is increased. Therefore, by adjusting the rotation amount (rotation angle) and the rotation direction of the impeller 54, it is possible to control the movement amount of the diaphragm blade base 32 that advances or retreats to the approximate center, that is, the diaphragm diameter of the opening S. it can.

When the aperture blade base 32 forms the diameter of the opening S that is larger than the radius of the opening S formed by the center-side contour 34a, the rectangular portion 35 forms a part of the opening S However, since the center side contour 35a of the rectangular part 35 is a linear shape that is continuous from the center side contour 34a of the ring-shaped part 34, the center is compared to the case of an arc shape with the center side contour 34a extended. Part of the side profile does not protrude into the opening S and does not reduce the roundness.

When the pattern image of the reticle R is projected and exposed on the wafer W by the above-described projection exposure apparatus 1, the reticle R on which the pattern to be transferred is drawn is transferred to the reticle stage 1 by a reticle loading mechanism (not shown). 8 to be transported and placed. At this time, the position of the reticle R is measured by a reticle alignment system (not shown) so that the reticle R is installed at a predetermined position, and the reticle R is controlled by a reticle position control circuit (not shown) according to the result. Set the position to a predetermined position. The surface of the wafer W to which the pattern of the reticle R is transferred is coated in advance with a resist, which is a photosensitive material, and in this state, the wafer W is transported by a wafer loading mechanism (not shown) and is placed on the wafer stage 27. Will be installed. The wafer W is aligned and held and fixed on the wafer stage 27. In the transfer of the pattern of the reticle of the first layer, the wafer W placed on the wafer stage 27 does not have a pattern on the wafer W, and is located at a predetermined position on the wafer stage 27, for example, a wafer. W is installed at a position determined based on its outer diameter (such as orientation flat or notch).

In the case of the second and subsequent transfer of the pattern to the wafer W, since the pattern exists on the wafer W, the mark attached to the previously transferred pattern is not shown. By measuring with the wafer alignment system, the reticle stage 18 and the wafer stage 27 are designed so that the pattern to be transferred has a predetermined positional relationship with the pattern previously transferred on the wafer W. Control the position of.

In addition, according to the pattern characteristics (pattern shape and pattern type) of the reticle R to be projected and exposed on the wafer W, the reticle is adjusted via the motor 8 in the variable aperture stop for the illumination system so that the optimum resolution and depth of focus are obtained. While rotating the plate 7, the rotation drive unit of the aperture stop 16 in the projection optical system PL is driven to change the size of the numerical aperture. Specifically, when the pattern of reticle R is a so-called rough pattern that requires relatively loose precision when performing double exposure, or when the wiring density is relatively low, that is, when it is a so-called isolated line Set a small numerical aperture to increase the depth of focus. Conversely, when the pattern of the reticle R is a so-called fine pattern that requires strict accuracy when performing double exposure, or when the wiring density is relatively high, for example, a line-and-space pattern In such a case, the resolution is improved by setting a large numerical aperture.

Thereafter, a pattern image is projected and exposed on the wafer W by a step-and-scan method using a light beam having a numerical aperture defined by the illumination system variable aperture stop and the aperture stop 16. In this transfer, a part of the pattern on the reticle R is selectively illuminated by the field stop 12, the reticle R is moved by the reticle stage 18, and the wafer W is synchronized with the reticle R by the wafer stage 27. This is a so-called scanning type transfer that moves. Alternatively, a step-and-repeat method in which the pattern on the reticle R to be transferred while the reticle R and the wafer W are stationary is illuminated and transferred at a time may be used. As described above, in the present embodiment, since the diaphragm blade base 32 is configured to linearly move back and forth toward the approximate center of the opening S, no gap is formed between the diaphragm blades adjacent in the circumferential direction. Therefore, even if the diaphragm blade bases 32 come into contact with each other, these contact portions are only at both circumferential ends of the respective diaphragm blade bases 32, which significantly reduces the contact area as compared with the conventional case. be able to. Therefore, dust generation and abrasion due to the contact between the aperture blade bases 32 can be largely suppressed, and the device can sufficiently withstand the high number of operations associated with the double exposure.

Moreover, in the present embodiment, between the adjacent diaphragm blade bases 32, the center direction of the opening S (See Fig. 5 and Fig. 8 in the direction perpendicular to the plane of the paper.) By further suppressing it, it is possible to withstand even higher number of operations. Further, in the present embodiment, in order to form a gap between the adjacent aperture blade bases 32, every other aperture blade base 32 is disposed in the same plane substantially orthogonal to the center direction of the opening S. Therefore, the installation range of the aperture blade base 32 in the center direction of the aperture S can be reduced, and the aperture stop 16 and the projection optical system PL, and further, the projection exposure apparatus 1 can be downsized.

Further, in the present embodiment, the linear movement of the diaphragm blade base 32 is realized by a simple configuration in which the rotational movement of the yaw wheel 54 is converted into the linear movement by the linear guide 36, so that the structure is complicated. It is possible to contribute to miniaturization and cost reduction of the device without becoming unnecessary.

On the other hand, in the present embodiment, the center-side contour 35 a of the rectangular portion 35 located on both circumferential sides of the diaphragm blade base 32 is in direct contact with the center-side contour 34 a of the arc-shaped annular portion 34. Because of the linear shape, even if the diameter of the opening S that is larger than the radius of the opening S formed by the center-side contour 34 a is formed, the center-side contour 35 a protrudes into the opening S. There is no. Therefore, in this embodiment, regardless of the size of the aperture diameter, it is possible to prevent the roundness of the opening S from being reduced, and to increase the size (aperture range) of the adjustable aperture S.

In addition, since the accuracy of the diameter of the aperture formed by the aperture stop 16 can be ensured in this manner, the projection exposure apparatus 1 can accurately form a fine pattern of the reticle R on the wafer W, Higher integration can be achieved by enabling formation of fine patterns also in semiconductor devices.

Furthermore, in this embodiment, since the bearing 39 is mounted on the convex portion 41 provided on the moving body 38 of the linear guide 36, the number of operation times can be increased with respect to the linear movement of the diaphragm blade base 32. It becomes possible. ·

FIG. 9 to FIG. 15 are diagrams showing a second embodiment of the present invention.

In these figures, the same elements as those of the first embodiment shown in FIGS. 1 to 8 are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 9 is an exploded perspective view showing a second embodiment of the diaphragm device according to the present invention. The aperture stop device 16 includes an aperture blade base 32 and an aperture blade 61, and a drive mechanism 33 that linearly moves the aperture blade base 32 and the aperture blade 61 toward the center of the opening S so as to be able to advance and retreat. It is roughly constituted from. Of the aperture stop 16, the aperture blades 61 are arranged on or substantially in the same plane as the pupil plane of the projection optical system PL.

As in the first embodiment, the aperture blades 61 are made of stainless steel that absorbs exposure light and generate little outgas, and have a shape obtained by dividing the ring shape in the circumferential direction as shown in FIG. It comprises a ring-shaped portion 62 presenting, and rectangular portions 63, 63, which are located on both circumferential sides of the ring-shaped portion 62 and have a substantially rectangular shape in plan view. Among the outer contours of the ring-shaped portion 62, the contour 62a on the center side (that is, the inner diameter side) of the opening S has an arc shape (arc portion) formed with a predetermined curvature. Also, of the outer contours of the rectangular portion 63, the contour 63a on the center side of the opening S is a linear shape (linear portion) continuously formed from the center contour 62a of the annular portion 62. ing.

The curvature of the center-side contour 62 a of the ring-shaped portion 62 is set almost in the middle between the maximum curvature and the minimum curvature of the opening S. That is, if the radius of the contour 62 a is R a, the maximum radius of the opening S (maximum aperture diameter) is RMAX, and the minimum radius (minimum aperture diameter) is RM IN, then Ra = (RMA X + RM IN) Set to 2. Further, the size of the diaphragm blade 61 in the circumferential direction is such that when the diaphragm blade 61 is positioned at the maximum diameter setting position of the opening S, no gap is formed between the circumferentially adjacent diaphragm blades 61. When the diaphragm blade base 3 2 is positioned at the minimum diameter setting position of the opening S, the center-side contour 6 3 a of the rectangular portion 6 3 overlaps with the circumferentially adjacent diaphragm blade 6 1, and the outer periphery of the opening S It is set to the minimum size that does not form a diameter. Therefore, when the opening S is set to the minimum diameter, the outline of the opening S is formed by the center-side outline 62 a of the annular portion 62.

In this embodiment, the diaphragm blade base 32 does not form the outer diameter of the opening S. Therefore, when the diaphragm blade 61 is positioned at the minimum diameter setting position of the opening S, the outer diameter of the diaphragm blade 61 is smaller. That is, the size is set so that no gap is formed between the diaphragm blade 61 and the annular portion 51. On the aperture blade base 32, a rectangular frame 71 in a plan view is provided at the center in the width direction. The frame body 71 is provided with a support portion 73 extending in the direction (radial direction) toward the center of the opening S at the center in the width direction. Openings 72, 72 are provided along the direction. As shown in FIG. 11, the frame 71 in the sectional view taken along the line BB in FIG. 10 has a U-shape. That is, the frame 71 has a box shape with the support portion 73 as a bottom plate, and the frame 71 has an internal space 74 formed therein. Further, as shown in FIG. 10, moving bodies 69, which constitute linear guides 66 described later, protrude from the diaphragm blade base 32 on both sides in the width direction of the frame 71. I have. A pair of the diaphragm blade base 32 and the diaphragm blade 61 is disposed in the same plane that is substantially orthogonal to the center direction (center axis) of the opening S every other as in the first embodiment. Like every other, they are installed at different heights.

The drive mechanism 33 includes a metal part 53 having an annular part 51 and a peripheral wall part 52, a wheel 5 4 rotatably fitted to the peripheral wall part 52 of the metal part 53, and a rotation for rotating the wheel 5 4. Drive part

(Not shown), a link mechanism 64, and linear guides 65, 66.

As shown in FIG. 10, the linear guide 65 includes a guide member 67 fixed to the aperture blade base 32 and a guide member 6 fixed to the aperture blade 61 as shown in FIG. 11. 7 and a moving body 6 8 that moves linearly along. The guide member 67 has substantially the same width as the support portion 73 of the frame 71, and is provided along the support portion 73 in the internal space 74 by a fastening member 75 such as a mounting screw. Fixed. A rectangular saddle member 76 shown in FIG. 12 is fixed to the moving body 68 so as to straddle the guide member 67 and the support portion 73.

The saddle member 76 has a flat plate portion 76 a disposed above the support portion 73 (the front side in FIG. 10 and the upper side in FIG. 13), and a longitudinal direction of the flat plate portion 76 a. (Radial direction) Center position and width direction (Circumferential direction) Legs 7 that are vertically suspended from both sides so as to pass through openings 7 2 of frame 7 1 and hold both sides of moving body 6 8 6b, 76b and the corner of the flat plate portion 76a are vertically installed so as to pass through the opening 72 of the frame 71, and as shown in FIG. And legs 76c to 76c for holding both ends in the vertical direction. The leg portion 76c has a length in contact with the diaphragm blade 61, and the diaphragm blade 61 is formed by a leg member 76c ( That is, it is fixed (at four places) to the saddle member 76). A shaft portion 78 protrudes from substantially the center of the flat plate portion 76a, and a bearing 79 is provided on the shaft portion 78 (see FIGS. 10 and 11). The guides 66 are arranged on both sides of the guide 65 and the frame 71 in the circumferential direction. The linear guide 66 includes a guide member 70 attached to a support ring 80 (see FIG. 10) fixed to the hardware 53, and a linear guide 66 provided on the diaphragm blade base 32 and along the guide member 70. And movable bodies 69. Each guide member 70 is installed in parallel with the guide member 67 of the linear guide 65.

As shown in FIG. 15, the link mechanism 64 includes a base 81 having a rotating shaft 81 a that is rotatably fitted around a shaft parallel to the central axis of the opening S to the hardware 53, and a base 81. And a link portion 82 extending in a direction perpendicular to the central axis from the tip of the link. At the tip of the link portion 82, a fitting groove 83 extending in the length direction and opening to the hardware 53 side (the lower side in FIG. 15) and fitting with the bearing 79 of the saddle member 76 is provided. Is formed. Further, a shaft portion 84 protrudes upward from the base portion 81 side from the center in the length direction of the link portion 82, and the shaft portion 84 has a fitting groove 4 6 for a wheel wheel 54. There is provided a bearing 85 slidably fitted on the bearing. The fitting groove 46 has the position of the shaft portion 84 when the inner diameter side contour of the aperture blade 61 forms the minimum aperture diameter of the opening S, and the inner diameter side contour of the aperture blade 61 has the maximum aperture diameter of the opening S. When the shaft portion 84 at the time of forming the diameter is connected at a predetermined angle (for example, 20 °) in the circumferential direction and is tied, for example, in a straight line or when the wicker 54 is rotated, the rotation angle and It is formed in a shape expressed by a function that makes the relationship with the aperture diameter linear.

(See Figure 9). Other configurations are the same as those of the first embodiment.

Next, the operation of the aperture stop 16 having the above configuration will be described.

When the rotation drive unit drives the wicker 54 with respect to the hardware 53 around the central axis of the opening S, for example, clockwise in FIG. 9, the bearing 85 moves along the fitting groove 46 of the wicker 54. Then, it moves to the center side of the opening S. The link portion 82 provided with the bearing 85 is rotated counterclockwise in FIG. 9 around the axis of the rotating shaft 81a by the movement of the bearing 85. In addition, due to the counterclockwise rotation of the rotating shaft 81a, the bearing 79 fitted into the fitting groove 83 of the link portion 82 has a distance between the rotating shaft 81a and the bearing 85, and the rotating shaft 81a. It moves a distance according to the ratio of the distance from 8 1 a to the bearing 79. That is, as shown in Fig. 15, the distance from the rotating shaft 81a to the bearing 85 is L1, the distance from the rotating shaft 8la to the bearing 79 is L2, and the moving distance of the bearing 85 is S1. Then, the shaft accompanying the movement of the bearing 85 The movement amount S 2 of the reception 79 is expressed by the following equation.

S 2 = (L 2 / L 1) X S 1

That is, the bearing 79 moves a distance (L 2 Z L 1) times the moving distance of the bearing 85. By the movement of the bearing 85, the diaphragm blade 61 moves relative to the diaphragm blade base 32 toward the center of the opening S along the guide member 67 via the saddle member 76 and the moving body 68. .

As the diaphragm blade 61 moves in the radial direction, the saddle member 76 engages with the frame 71 at the center side of the opening S as shown in FIG. Movement is restricted. By restricting the movement of the saddle member 76, the diaphragm blade base 32 moves linearly along the guide member 70 of the linear guide 66 this time. The diaphragm blade 61 moves again toward the center of the opening S with the linear movement of the diaphragm blade base 32. At this time, the diaphragm blade 61 linearly moves along the guide member 70 of the linear guide 66 that linearly moves the diaphragm blade base 32. If the friction force at the linear guide 65 is larger than the friction force at the linear guide 66, the movement of the bearing 85 causes the diaphragm blade base 32 and diaphragm blade 61 to move physically. However, even if the saddle member 76 is engaged with the frame 71 outside the opening S, the center side contour of the diaphragm blade base 32 is set so as not to protrude beyond the center side contour of the diaphragm blade 61. Therefore, there is no problem in forming the aperture diameter by the aperture blades 61.

On the other hand, the rotation of the rotating shaft 8 1a by rotating the wicker wheel 54 with respect to the hardware 53 in the counterclockwise direction in FIG. 5 retreats with respect to the center of the opening S. Thereby, the diaphragm blade 61 moves in a direction away from the central axis of the opening S, and the diaphragm diameter of the opening S is enlarged. Therefore, by adjusting the amount of rotation (rotation angle) and the direction of rotation of the impeller 54, the amount of movement of the diaphragm blade 61, which advances or retreats to the approximate center, ie, the diameter of the aperture S, can be controlled to an arbitrary size. can do. For example, by setting L 2: L l = 2: 1, it is possible to set the aperture diameter in a range about twice as large as that of the first embodiment. As a result, the aperture blade 61 is configured to move linearly using both the linear guides 65 and 66. As described above, in the present embodiment, in addition to obtaining the same operation and effect as the above-described first embodiment, the diaphragm blade base 32 and the diaphragm blade 61 that can move relative to each other are used. Therefore, even if the aperture blade having the same size as that of the first embodiment is used, the size of the adjustable aperture S (aperture range) can be doubled without increasing the aperture stop 16 in a planar manner. Can be as wide as possible. Further, in the present embodiment, since the guide member 67 for relatively moving the aperture blade base 32 and the aperture blade 61 is provided on the aperture blade base 32, it is compared with a case where the guide member 67 is provided at another location. The aperture stop 16 and, consequently, the projection optical system PL can be reduced in size, and the amount of rotation of the rotating member 54 can be reduced when adjusting the aperture diameter of the aperture S. The time required for work can be reduced.

In the second embodiment, the force using the link mechanism 64 to relatively move the aperture blade base 32 and the aperture blade 61 is not limited to this. For example, the aperture blade base 3 2 The wire that is engaged at the center edge of the wire is folded back, and the wire tip is fixed to the diaphragm blade 61, or the gear with a gear ratio of 1: 2 is provided between the diaphragm blade base 32 and the diaphragm blade 61. It is also possible.

Further, in the above embodiment, the aperture device of the present invention is applied to the aperture stop of the projection optical system PL. However, the present invention is not limited to this, and may be applied to a variable aperture stop for an illumination system. Further, in the above embodiment, the moving body 38 of the linear guide 36 is provided with the convex portion 41 and the whirler 54 is provided with the fitting groove 46. On the contrary, the moving body 38 has A configuration may be adopted in which a fitting groove is provided, and a convex portion is provided in the wheel 54. Also in this case, it is desirable to provide a bearing on the projection.

Further, in the above embodiment, the aperture blade base 32 and the aperture blade 61 are configured to move linearly in a direction orthogonal to the center direction of the opening S. For example, the adjacent aperture blade bases 32 approach the center. , The linear movement direction may be slightly inclined within an allowable error range with respect to the above-mentioned orthogonal direction so as to gradually separate in the center direction. In this case, the diaphragm blade base 32 and the diaphragm blade 61 are deflected by their own weight toward the center, and can be prevented from coming into contact with adjacent diaphragm blades even when approaching.

The substrate of the present embodiment is not only a semiconductor wafer W for a semiconductor device, but also a glass substrate for a liquid crystal display device, a ceramic wafer for a thin film magnetic head, or a mask or reticle used in an exposure apparatus. The original plate (synthetic quartz, silicon wafer) etc. are applied. The projection exposure apparatus 1 includes a step-and-scan type scanning exposure apparatus (scanning stepper; US Pat. No. 5,473,410) for scanning and exposing the pattern of the reticle R by synchronously moving the reticle R and the wafer W. The present invention can also be applied to a projection exposure apparatus (stepper) of a step-and-repeat type in which the pattern of the reticle R is exposed while the reticle R and the wafer W are stationary, and the wafer W is sequentially moved in steps.

The type of the projection exposure apparatus 1 is not limited to an exposure apparatus for manufacturing a semiconductor device that exposes a semiconductor device pattern onto a wafer W, but may be an exposure apparatus for manufacturing a liquid crystal display element, a thin-film magnetic head, an imaging device (CCD), or the like. It can be widely applied to an exposure apparatus for manufacturing a reticle and the like. Further, the aperture device of the present invention can be applied not only to a projection exposure device but also to an optical apparatus (for example, a camera) including various aperture devices. The magnification of the projection optical system PL may be not only a reduction system but also an equal magnification system or an enlargement system. Further, as the projection optical system PL, when far ultraviolet rays such as an excimer laser are used, a material which transmits far ultraviolet rays such as quartz or fluorite is used as a glass material, and when a F 2 laser or X-ray is used, a catadioptric system is used. An optical system of a refraction system (a reticle R of a reflection type is also used), and when an electron beam is used, an electron optical system including an electron lens and a deflector may be used as the optical system. The optical path through which the electron beam passes must be vacuum.

When a linear motor (see USP5,623,853 or USP5,528,118) is used for the wafer stage 27 reticle stage 18, either an air levitation type using an air bearing or a magnetic levitation type using Lorentz force or reactance force is used. You can use it. Further, each of the stages 18 and 27 may be of a type that moves along a guide, or may be a guideless type that does not have a guide.

The drive mechanism of each stage 18 and 27 consists of a magnet unit (permanent magnet) in which magnets are arranged two-dimensionally and an armature unit in which coils are arranged two-dimensionally. A planar motor for driving 18 and 27 may be used. In this case, one of the magnet unit and the armature unit is connected to the stages 18 and 27, and the other of the magnet unit and the armature unit is connected to the moving surface side of the stages 18 and 27 (base). ). The reaction force generated by the movement of the wafer stage 27 is not transmitted to the projection optical system PL so that the reaction force is not transmitted to the projection optical system PL, as described in Japanese Patent Application Laid-Open No. Hei 8-166475 (USP 5,528,118). It is possible to mechanically escape to the floor (ground) using members. The present invention is also applicable to an exposure apparatus having such a structure.

The reaction force generated by the movement of the reticle stage 18 is not transmitted to the projection optical system PL so as to be described in Japanese Patent Application Laid-Open No. 8-3330224 (US S / N 08 / 416,558). Also, you can mechanically escape to the floor (ground) using the frame member. The present invention is also applicable to an exposure apparatus having such a structure.

As shown in Fig. 17, a micro device such as a semiconductor device has a step 201 for designing the function and performance of the micro device, a step 202 for manufacturing a reticle R based on this design step, and a silicon material. Step 203 of manufacturing wafer W from wafer, exposure processing step 204 of projecting and exposing the pattern of reticle R onto wafer W by projection exposure apparatus 1 of the above-described embodiment, and developing wafer W, device It is manufactured through an assembly step (including a dicing step, a bonding step, and a package step) 205 and an inspection step 206.

As described above, the projection exposure apparatus 1 according to the embodiment of the present application is capable of controlling various subsystems including the respective components listed in the claims of the present application to predetermined mechanical accuracy, electrical accuracy, and optical accuracy. Manufactured by assembling to keep. Before and after this assembly, adjustments to achieve optical accuracy for various optical systems, adjustments to achieve mechanical accuracy for various mechanical systems, and various electrical The air system is adjusted to achieve electrical accuracy. The process of assembling the exposure apparatus from various subsystems includes mechanical connections, wiring connections of electric circuits, and piping connections of pneumatic circuits among the various subsystems. It goes without saying that there is an individual assembly process for each subsystem before the assembly process from these various subsystems to the exposure apparatus. After the process of assembling the various subsystems into the exposure apparatus is completed, comprehensive adjustments are made to ensure the various accuracy of the entire exposure apparatus. It is desirable to manufacture the exposure equipment in a clean room where the temperature and cleanliness are controlled. Industrial applicability

An aperture device according to the present invention is configured such that each of the plurality of aperture blades is provided with an outer ring of each aperture blade.

Of 15, any point of the contour on the center side of the opening is moved linearly toward the approximate center of the opening. As a result, in this aperture device, dust generation and abrasion can be greatly reduced by greatly reducing the contact area between the aperture blades, and it is sufficient for the high number of operations associated with the execution of double exposure. Can withstand.

Claims

The scope of the claims

1. A diaphragm device having a plurality of diaphragm blades for adjusting the size of an aperture, wherein each of the plurality of diaphragm blades is an arbitrary one of the outer contours of each diaphragm blade at the center side of the aperture. A drive mechanism is provided for linearly moving the point (4) linearly toward the center of the opening.

2. The diaphragm device according to claim 1, wherein

Each of the aperture blades is arranged with a gap between adjacent aperture blades in a direction substantially parallel to the central axis of the opening.

3. The diaphragm device according to claim 2, wherein

Every other one of the aperture blades is disposed in the same plane substantially orthogonal to the central axis of the opening.

4. The squeezing device according to claim 1, wherein

Among the outer contours of the aperture blade, a contour on the center side of the opening has an arc portion having a predetermined curvature and a straight line portion continuously formed from the arc portion.

5. The diaphragm device according to claim 1, wherein

The drive mechanism includes: a rotation member that rotates about a substantially central axis of the opening as a rotation axis; and a conversion member that converts rotational movement of the rotary member into linear movement of the plurality of aperture blades.

6. The aperture device according to claim 5, wherein

A fitting groove is provided on one of the rotating member and the conversion member,

The other of the rotating member and the conversion member is provided with a convex portion that slides by fitting into the fitting groove,

A bearing is mounted on the projection.

7. The aperture device according to claim 1, wherein

An aperture blade base for holding the aperture blade so as to be movable in the linear direction;

8. The diaphragm device according to claim 7, wherein

The diaphragm blade base linearly moves in the same direction as the direction of movement of the diaphragm blade in accordance with the linear movement of the diaphragm blade.

9. The aperture device according to claim 7, wherein

A rotation member that rotates about a substantially central axis of the opening as a rotation axis; and a rotation movement of the rotation member that linearly moves the diaphragm blade, and after the diaphragm blade moves, the diaphragm blade. A link mechanism for linearly moving the base.

10. The diaphragm device according to claim 7, wherein

The diaphragm blade is provided with a guide member for guiding the linear movement of the diaphragm blade base.

11. A projection optical system having an aperture stop whose variable numerical aperture is variable, wherein the aperture device according to claim 1 is used as the aperture stop.

12. A projection exposure apparatus for projecting and exposing a pattern image of a mask illuminated by a light beam onto a substrate,

The aperture device according to claim 1, wherein the aperture device is disposed in an optical path of the light beam and has a variable numerical aperture.

13. The projection exposure apparatus according to claim 12, wherein

A projection optical system for transferring the pattern image of the mask onto the substrate, wherein the aperture stop included in the aperture device is disposed on a pupil plane of the projection optical system; I have.

14. A method for manufacturing a microphone-mouth device manufactured by exposing a photosensitive substrate with a pattern image of a mask,

A step of exposing the photosensitive substrate with the device pattern image of the mask using the projection exposure apparatus according to claim 12, and a step of developing the exposed photosensitive substrate.