JP2002110529A - Projection exposure apparatus and microdevice manufacturing method using the apparatus - Google Patents

Abstract

An object of the present invention is to provide a projection exposure apparatus capable of transferring a reticle pattern onto a photosensitive substrate with high accuracy by illuminating light having high uniformity, and a method for manufacturing a micro device using the apparatus. An illumination optical system for illuminating a reticle having a predetermined pattern formed thereon, and a projection optical system for projecting and exposing a pattern image of the reticle illuminated by the illumination optical system to a photosensitive substrate. System 8 and a scanning device MT for scanning the reticle 3 and the photosensitive substrate 9 with respect to the projection optical system 8.
The illumination optical system 1 has a light intensity of the illumination light at at least one of the light source LS side and the reticle 3 side with a predetermined position 130 optically conjugate with the imaging plane of the projection optical system 8 interposed therebetween. A light limiting member A1 for adjusting the distribution;
The distance D from the predetermined position to the light restricting member A1 satisfies a predetermined condition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for transferring a mask pattern onto a substrate in a lithography process for manufacturing a device such as a semiconductor device, a liquid crystal display device, a plasma display device, a micro machine or a thin film magnetic head. The present invention relates to a projection exposure apparatus used for a semiconductor device and a microdevice manufacturing method using the apparatus.

[0002]

2. Description of the Related Art In order to increase the exposure field (each shot area on a wafer) and increase the throughput of an exposure process without increasing the size of a projection optical system, a reticle as a mask is required for the projection optical system. 2. Description of the Related Art A scanning exposure type projection exposure apparatus (hereinafter, referred to as a "scanning exposure apparatus"), such as a step-and-scan method, for synchronously scanning a wafer as a photosensitive substrate has been developed. In this type of scanning exposure apparatus, the integrated exposure amount at each point on the wafer is
Averaged by the integration effect in the scanning direction,
In the non-scanning direction orthogonal to the scanning direction, for example, the influence of the uneven illuminance in the non-scanning direction in the slit-shaped illumination area appears as it is. Further, the illumination optical system included in the projection exposure apparatus may cause uneven illuminance due to aberration of lens components, manufacturing errors, and the like.

[0003]

The variation of the optical characteristics of the optical member or the optical system, for example, the variation of the transmittance on the optical path of the exposure light to the wafer causes the uniformity of the integrated exposure amount on the wafer. Can be increased. Thereby, illuminance unevenness can be corrected to some extent. However, when a change in transmittance or the like is caused, the telecentricity collapses (hereinafter, referred to as “telecentricity deviation”) or a light flux having a predetermined numerical aperture at a certain image height (hereinafter, referred to as “σ light flux”). This causes non-uniformity in the amount of light inside.

[0004] Telecentricity deviation and non-uniformity of the amount of light in the sigma beam impair the uniformity of the illuminating light, thereby lowering the transfer accuracy of the reticle pattern. Therefore, the yield of the final product also decreases. In recent years, the performance such as the resolving power required for a projection exposure apparatus has come very close to the theoretically calculated limit. As is generally well known, the optimal set values of the constants of the optical system (the numerical aperture of the projection lens, the numerical aperture of the illumination system, etc.) differ depending on the reticle pattern. As a matter of course, the apparatus side is required to be able to select an optimum optical system constant according to the mask pattern.

For this reason, a stop other than a circular stop may be used as the aperture stop. For example, a ring-shaped diaphragm as shown in FIG. 18A or a multi-aperture diaphragm as shown in FIG. 18B. Regarding the aperture stops in FIGS. 18A and 18B,
I will explain briefly. When the reticle pattern becomes finer and exposure is performed near the resolution limit of the device, of the luminous flux emitted from the aperture stop of the illumination system, the light that contributes to the resolution is from the periphery of the aperture stop. Only the emitted light is emitted, and the light emitted from the central part of the opening has only a function of lowering the contrast of the image. In other words, when transmitting the information of the reticle to the wafer, only the light emitted from the periphery of the aperture stop gives energy for information transmission, and the light emitted from the center of the aperture only generates noise, so to speak. It will be. Therefore, it can be said that it is desirable not to emit light from the center of the aperture stop.
From such an idea, an aperture as shown in FIG. 18A has been devised. The stop shown in FIG. 18B is a stop in the case where the pattern to be resolved is further limited to only vertical lines and horizontal lines. In this case, light emitted from the upper, lower, left and right sides of the aperture stop is merely noise. For this reason, a diaphragm as shown in FIG. 18B has been devised which further shields the upper, lower, left and right sides of the aperture diaphragm.

In the case of such an aperture which is not a circular aperture, only a part of the transmitted light amount of the fly-eye lens is used, and light is blocked by a modified aperture stop in many parts including a central part near the optical axis. For this reason, the above-mentioned problems of non-uniformity of the light amount in the σ beam and deviation of telecentricity occur. Therefore, it is difficult to make the pattern of the reticle highly accurate on the photosensitive substrate.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a projection exposure apparatus capable of transferring a reticle pattern onto a photosensitive substrate with high accuracy by using illumination light having high uniformity, and a micro device using the apparatus. It is intended to provide a manufacturing method.

[0008]

Means for solving the above problems will be described with reference to the accompanying drawings. The invention according to claim 1 is an illumination optical system for illuminating a mask on which a predetermined pattern is formed. A projection optical system 8 for projecting and exposing a pattern image of the mask 3 illuminated by the illumination optical system 1 onto a photosensitive substrate 9; A scanning device MT for scanning the transparent substrate 9, wherein the illumination optical system 1 is located between the light source 1 side and the mask 9 side with a predetermined position optically conjugate with the imaging plane of the projection optical system 8. A light limiting member A1 for adjusting the light intensity distribution of the illuminating light at at least one of the positions.
A projection exposure apparatus characterized in that the projection exposure apparatus is arranged in an illumination light path such that a distance D to the illumination light path satisfies the following condition.

[0009]

Here, Wx: the length in the longitudinal direction of the exposure field formed on the photosensitive substrate 9, NA _ill : the illumination optical system 1 on the photosensitive substrate side (image side) of the projection optical system 8. Maximum value of numerical aperture, M: imaging magnification from the predetermined position to the imaging plane of the projection optical system 8.

The invention according to claim 2 is an illumination optical system 1 for illuminating a mask 3 on which a predetermined pattern is formed, and the mask 3 illuminated by the illumination optical system 1.
A projection optical system 8 for projecting and exposing the pattern image on the photosensitive substrate 9, and a scanning device MT for scanning the mask 3 and the photosensitive substrate 9 with respect to the projection optical system 8, The illumination optical system 1 includes a first light restricting member A1 disposed at a first position on the light source 1 side with a predetermined position optically conjugate with the imaging plane of the projection optical system 8 and a first light restricting member A1 on the mask 3 side. And a second light restricting member B1 disposed at the position No. 2 and wherein the first and second light restricting members A1 and B1 adjust the light intensity distribution of the illumination light. I do.

In the invention according to claim 3, the first light restricting member A1 is provided to face the first surface PL1 passing through the first position and crossing the optical axis AX of the illumination optical system 1. And a second light limiting member B1 is provided to face the second surface PL2 passing through the second position and crossing the optical axis AX of the illumination optical system 1. It is desirable to have a pair of second dimming elements B1, B3.

Further, in the invention according to claim 4, it is desirable that the first light restricting member A1 and the second light restricting member B1 are arranged at an equal distance D to a predetermined position.

In the invention according to claim 5, an illumination optical system 1 for illuminating a mask 3 on which a predetermined pattern is formed, and a pattern image of the mask 3 illuminated by the illumination optical system 1 is exposed. A projection optical system 8 for projecting and exposing a transparent substrate 9 and the mask 3 with respect to the projection optical system 8.
And a scanning device MT for scanning the photosensitive substrate 9, and the illumination optical system 1 includes changing devices MT 1, 116, MT 2, 128 for changing illumination conditions for the mask 3.
And at least one of the light source 1 side and the mask 3 side with a predetermined position optically conjugate with the imaging plane of the projection optical system 8 in response to the change of the illumination condition by the change devices MT1, 116, MT2, 128. It is desirable to have a light limiting member A1 or the like that adjusts the light intensity distribution of the illumination light at the position.

Further, in the invention according to claim 6, a step of applying a photosensitive material on the substrate 9 and a step of projecting an image of the pattern of the mask 3 on the substrate 9 via the projection exposure apparatus; Developing the photosensitive material on the substrate 9; and forming a predetermined circuit pattern on the substrate 9 using the developed photosensitive material as a mask. provide.

In the invention according to claim 7, an illumination step of illuminating the mask 3 on which a predetermined pattern is formed using the illumination optical system 1, and projecting a pattern image of the mask 3 onto the photosensitive substrate 9. A scanning exposure step of scanning and exposing a pattern image of the mask 3 to the photosensitive substrate 9 by causing the projection optical system 8 to scan the mask 3 and the photosensitive substrate 9; And a light restricting member A1 disposed at or near a position optically conjugate with the imaging plane of the projection optical system 8 in response to the change of the illumination condition in the change step. And a method for manufacturing a microdevice, comprising an adjusting step of adjusting the light intensity distribution of the illumination light using the method.

Further, in the invention according to claim 8, in the adjusting step, the photosensitive substrate 9 is corrected by the light restricting member A1 or the like in order to correct the exposure unevenness on the photosensitive substrate 9.
It is desirable to adjust the light intensity distribution at the point.

[0018]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

(First Embodiment) FIG. 1 is a view showing a schematic configuration of a projection exposure apparatus according to a first embodiment. In FIG. 1, a projection optical system 8 constituting the projection optical system
Are set parallel to the optical axis AX, the Y axis is set parallel to the plane of FIG. 1 in the plane perpendicular to the optical axis AX, and the X axis is perpendicular to the plane of FIG. A reticle (mask) 3 is disposed as a projection master having a predetermined circuit pattern formed on an object surface of the projection optical system 8, and a photoresist as a substrate is applied to an image surface of the projection optical system 8. A wafer 9 is arranged.

The exposure illumination light supplied from the light source LS passes through the illumination unit 1A and then passes through the relay optical system (imaging optical system) 2 to uniformly illuminate the reticle 3 on which a predetermined pattern is formed. I do. In the optical path from the light source LS to the illumination unit 1A, one or a plurality of bending mirrors for deflecting the optical path as necessary are arranged. When the light source LS and the projection exposure apparatus main body are separate bodies, an automatic tracking unit that always directs the direction of the light from the light source LS to the projection exposure apparatus main body, or a light beam cross-sectional shape of the light from the light source LS is specified. An optical system such as a shaping optical system and a light amount adjusting unit for shaping to the size and shape of the above is arranged.

The illumination unit 1A includes, for example, an optical integrator formed of a fly-eye lens or an internal reflection type integrator to form a surface light source of a predetermined size and shape, and a size of an illumination area on the reticle 3 as described later. It has an optical system such as a field stop (scan slit or reticle blind) for defining the shape.

Here, the relay optical system 2 has two lens groups of a front group 2A and a rear group 2B, and an image of a slit-shaped opening of the field stop 130 in the illumination unit 1A is formed by the relay optical system. Is projected on the mask 3. Therefore,
The relay optical system 2 functions as an imaging optical system that forms an image of the field stop.

The reticle 3 is held on a reticle stage 5 via a reticle holder 4 in parallel with the XY plane. A pattern to be transferred is formed on the reticle 3, and a rectangular (slit-shaped) pattern area having a long side along the X direction and a short side along the Y direction in the entire pattern area is illuminated. Is done. The reticle stage 5 can be moved two-dimensionally along the reticle surface (ie, XY plane) by the action of a drive system (not shown), and its position coordinates are measured by an interferometer 7 using a reticle moving mirror 6. And the position is controlled.

The light from the pattern formed on the reticle 3 is transmitted through a projection optical system 8 to a wafer 9 serving as a photosensitive substrate.
A reticle pattern image is formed thereon. The projection optical system 8
An aperture stop AS having a variable aperture is provided near the pupil position, and is substantially telecentric on the reticle 3 side and the wafer 9 side.

The wafer (substrate) 9 is held on a wafer stage (substrate stage) 11 via a wafer holder 10 in parallel with the XY plane. Then, so as to optically correspond to a rectangular illumination area on the reticle 3,
On the wafer 9, a pattern image is formed in a rectangular (rectangular or slit-shaped) exposure region having a long side along the X direction and a short side along the Y direction.

The wafer stage 11 can be moved two-dimensionally along the wafer surface (that is, the XY plane) by the action of a drive system (not shown), and its position coordinate is the interferometer 13 using the wafer moving mirror 12. And the position is controlled.

As described above, the visual field area (illumination area) on the reticle 3 and the projection area (exposure area) on the wafer 9 defined by the projection optical system 8 have a rectangular shape having a short side along the Y direction. It is. Therefore, while controlling the positions of the reticle 3 and the wafer 9 using the drive system and the interferometers (7, 13), the rectangular exposure area and the illumination area are arranged along the short sides of the illumination area, ie, along the Y direction, as indicated by arrows. By moving (scanning) the reticle stage 5 and the wafer stage 11 and, consequently, the reticle 3 and the wafer 9 synchronously by the drive unit MT, the wafer 9 has a width equal to the long side of the exposure area and Scanning amount (movement amount) of wafer 9
The reticle pattern is scan-exposed to an area having a length corresponding to. For example, the direction in which the reticle 3 and the wafer 9 relatively move is such that when the reticle 3 moves rightward (+ Y direction) on the paper when the projection lens 8 is an imaging optical system once, the wafer 9 moves leftward on the paper. The scanning exposure is performed by moving in the (-Y direction).

As described above, the aperture stop AS for changing the numerical aperture (NA) is provided near the pupil plane of the projection lens 8. The control / arithmetic processing unit PC controls the size of the opening of the aperture stop AS based on information input from the console CNS by the operator or information stored in the memory unit MU in advance. And the control and arithmetic processing unit PC
Makes the NA variable by changing the size of the aperture of the aperture stop AS during scanning exposure.

Next, the optical system of the projection exposure apparatus will be described in more detail with reference to FIG. The light beam from the light source LS is formed into a desired shape (for example, a square shape) by the beam expander 112, and after the optical path is bent by 90 degrees by the mirror 114, the diffractive optical element 116 as a first integrator (first optical integrator) is formed.
Incident on. The first integrator includes a plurality of integrated diffraction elements 1 having desired divergence angle characteristics and an integration effect.
16 or turret plate 11 on which refractive element 100 is arranged
8 is provided. The light beam from the diffractive optical element 116 as the first integrator is transmitted via the relay optical system 120 to the second integrator (second optical integrator).
A desired illumination area is formed on the incident surface of the fly-eye lens 124 as the target. In addition, the fly-eye lens 124 is configured by an aggregate of many lens elements.

An aperture stop 126 corresponding to the illumination area is arranged on the exit surface of the second integrator 124. The position of the aperture stop 126 forms a secondary light source group. Here, a turret plate 128 as a variable aperture stop means
Is provided with a number of aperture stops having different shapes and sizes of apertures, including an aperture stop 126, and having a desired size and shape by rotating a turret plate 128 via a drive system MT2. An aperture stop having an aperture is set in the optical path. Thus, the size and shape of the secondary light source group (light intensity distribution) formed on the exit side (pupil position of the illumination optical system) of the fly-eye lens 124 as the second integrator can be accurately defined. The first
In response to switching of the optical member (diffractive optical element 116 or fly-eye lens 100) by the integrator, the variable aperture stop means 128 operates to set an aperture stop having an aperture having an appropriate size and shape in the optical path. I do. further,
As will be described later, if the relay optical system 120 is constituted by a zoom optical system, the variable aperture stop means 128 changes the aperture stop having an opening having an appropriate size and shape to an optical path according to the magnification of the relay optical system 120. May be set.

The light beam from the secondary light source group irradiates the field stop 130 via the condenser optical system 228 in a superimposed manner. In the vicinity of the field stop 130, a light shielding plate A1 is arranged as a filter for correcting uneven illuminance. The distance D between the light shielding plate A1 and the field stop 130 will be described later.
Further, since the present invention is suitable for a scanning type exposure apparatus, the field stop 130 also has a mechanism for moving in synchronization with the scanning exposure operation. That is, control is performed so that unnecessary exposure is not performed throughout the scan exposure.

At an appropriate position near the field stop 130, in order to optimize the integrated exposure distribution after scanning exposure,
A fixed auxiliary stop SB having a slit-shaped opening as shown in FIG. 19 is arranged. The shaded area in FIG. 19 indicates a light-shielded area. As shown in FIG. 1, the illumination optical system 1 has an illumination unit and a relay optical system 2. The field stop 130 is imaged at the position of the reticle 3 by the imaging optical system 132. That is, the position of the field stop 130 and the position of the reticle 3 have a conjugate relationship.

The reticle 3 is illuminated by the illumination optical system 1 described above, and the circuit pattern drawn on the reticle 3 is projected via the projection optical system 8 onto the resist-coated wafer 9. By scanning the reticle 3 and the wafer 9 synchronously in this arrangement, all the patterns drawn on the reticle 3 are exposed on the wafer 9. In this embodiment,
A plurality of first integrators 116 are arranged in the turret 118, and various types of switching can be performed by driving the motor MT1.

Here, in FIG. 2, the turret plate 1
Numeral 18 holds a fly-eye lens 100 and a diffractive optical element 116 which are constituted by an aggregate of a large number of lens elements. As shown in FIG. 2, the diffractive optical element 11
6 is set in the optical path, the diffractive optical element 116
Converts the incident light into an annular light flux, and the converted light passes through the relay optical system 120, and then an annular illumination area is formed on the incident surface of the fly-eye lens 124 as the second integrator. Further, a secondary light source group (or annular light intensity distribution) having an overall annular shape is formed on the exit side (pupil position of the illumination optical system) of the fly-eye lens 124 as the second integrator. Thus, the mask 3 can be illuminated under the annular illumination condition.

As shown in FIG. 2, the driving system MT
When the turret plate 118 is rotated via 1 to set the fly-eye lens 100 in the optical path, the fly-eye lens 100 divides the incident light into a wavefront and forms a large number of light source images on the exit side. After the light from these many light source images passes through the relay optical system 120, a substantially circular illumination area is formed on the incident surface of the fly-eye lens 124 as the second integrator, and thus the fly-eye lens as the second integrator On the exit side of the lens 124 (the pupil position of the illumination optical system), a secondary light source group (or a circular light intensity distribution) having a substantially circular shape as a whole is formed. Thereby, the mask 3 can be illuminated under normal illumination conditions (circular illumination conditions). The above turret plate 11
At 8, although not shown, a diffractive optical element for quadrupole illumination and a diffractive optical element for multipole illumination are held, and the exit side (pupil position of the illumination optical system) of the fly-eye lens 124 is approximately 4 A secondary light source group (4
It is also possible to form a polar or multipolar light intensity distribution and illuminate the mask 3 under quadrupole or multipole illumination conditions.

Further, if the relay optical system 120 is constituted by a zoom optical system, the outer diameter of the annular light intensity distribution formed at the pupil position of the illumination optical system during annular illumination can be varied, and the illumination during normal illumination. The outer diameter of the circular light intensity distribution formed at the pupil position of the optical system can be varied, and the quadrupole shape or the multipole shape formed at the pupil position of the illumination optical system at the time of quadrupole or multipole illumination can be changed. The position of each pole with respect to the center of the light intensity distribution can be made variable.

As described above, by switching the optical members (100, 116) in the first integrator, normal illumination (illumination that forms a circular light distribution on the pupil of the illumination optical system) and annular illumination (illumination optics) Illumination that forms a ring-shaped light distribution on the pupil of the system), quadrupole illumination (illumination that forms a quadrupolar light distribution on the pupil of the illumination optical system), and multipole illumination (multipole illumination on the pupil of the illumination optical system) Illumination that forms the light distribution of the illumination) can be switched. At this time, MT2 is driven in synchronization with the selection of the first integrator. Accordingly, it is desirable that, out of the plurality of aperture stops provided on the turret 128, an aperture stop having a corresponding appropriate size and shape is selected and set in the optical path.

The first integrator 116 is a fly-eye lens, a microlens array manufactured by etching, an integrated diffraction element or a refractive element having desired divergence angle characteristics and an integration effect (these are also manufactured by etching). ). Further, the second integrator 124 includes a fly-eye lens,
Micro lens array manufactured by etching,
It can be composed of a rod lens or the like.

Next, the light amount distribution shape when there is uneven illuminance will be described with reference to FIGS. The light amount distribution of the uneven illuminance on the wafer 9 is represented by the illuminance distribution E (X)
As a function of the position X in the non-scanning direction can be expressed as: The origin of the position X is a straight line that passes through the optical axis AX of the projection optical system 8 and is parallel to the Y axis.

E (X) = a · (X−b) ² + c · X + d (3)

In the equation (3), the quadratic coefficient a represents the uneven illuminance of the convex (a> 0) or concave (a <0) with respect to the position X,
The shift coefficient b indicates the shift amount of the symmetric axis of the uneven illuminance from the optical axis AX in the X direction, the first-order coefficient c indicates the so-called first-order tilt unevenness, and the coefficient d indicates the constant illuminance (offset) independent of the position X. Each is represented. The values of these coefficients a to d are obtained by, for example, the least squares method from actual measurement data as described later. Then, the obtained value is recorded as the state of the illuminance unevenness in the non-scanning direction (that is, the integrated exposure amount distribution in the non-scanning direction).

Specifically, the illuminance distribution E shown in FIG.
In (X), when the coefficient a is a positive value (FIG. 3A), “secondary convex illuminance unevenness” is used, and when the coefficient a is a negative value (FIG.
(B)) is referred to as “secondary concave illuminance unevenness”, and the case where coefficient a is zero and coefficient c is positive or negative is referred to as “primary tilt illuminance unevenness”. Note that in this example, the illuminance distribution E (X) is
Although the approximation is performed by the following function, E (X) may be approximated by a function of the third order or higher of the position X as described later, or may be further approximated by an exponential function or the like.

FIG. 4A shows a plane (xy) perpendicular to the optical axis.
It is a figure which shows the shape of the light shielding plate A1 (in a plane). Here, in the embodiment shown in FIG. 2, the irradiated surface (the reticle 3,
A light shielding plate A1 as an adjusting member (light limiting member) for correcting non-uniformity of the illuminance distribution or the light intensity distribution on the wafer 9) is arranged in the XZ plane. However, in order to facilitate understanding, in the following description, for example, FIGS. 4, 5, 19, and 20 will be described on the assumption that the light shielding plate A1 in FIG. 2 is arranged on the XY plane. In this case, it is assumed that the light-shielding plate A1 in FIG. 2 is obtained by removing the reflecting mirror 134 in FIG. 2, and the lens system 2A and the light-shielding plate A1 are arranged in order toward the lens system 2B.

The light shielding plate A1 has a pattern shape (hatched portion) for correcting secondary concave uneven illuminance. As described above, in the scanning direction (Y direction), the integrated exposure amount obtained by integrating the illuminance distribution of the scan slit width in the scanning direction (Y direction) is substantially equal. This integrated exposure amount is a light amount that is substantially uniform in the Y direction. On the other hand, in the non-scanning direction (X direction), for example, the above-described secondary concave illuminance unevenness occurs.

For this reason, in the non-scanning direction (X direction), the light intensity around the exposure area is reduced by increasing the light shielding ratio in a region where the absolute value of the X coordinate is large, that is, at both ends of the light shielding plate A1. . Further, in a region having a small X coordinate, that is, in the central portion of the light shielding plate A1, the light intensity at the central portion of the exposure region is not reduced so much by reducing the light shielding ratio.

That is, in the case of the secondary concave illuminance unevenness, the light amount distribution in the non-scanning direction (X direction) on the wafer 9 is made substantially uniform by using the light shielding plate A1 having the light shielding pattern shown in FIG. Can be

Here, the light-shielding plate A1 having such a configuration is the same as that shown in FIG.
As described above, the lens is disposed at a position defocused in the optical axis (Z-axis) direction by a predetermined distance D from the position of the field stop 130. The details of the scanning exposure in this arrangement will be described with reference to FIG. FIG. 20 shows an XY cross section of the optical path at a predetermined position along the Z direction where the light shielding plate A1 is arranged. FIG. 20 shows the fixed auxiliary aperture S shown in FIG.
The shadow of the light-shielding portion that B makes at the position of A1 is also displayed at the same time. A thick line C in FIG. 20 indicates the outermost circumference of the light beam arriving at each point Q, Q0, Q1, P, P0, P1, etc. on the exposure visual field from the aperture stop 126. This will be referred to as a sigma luminous flux. That is, since the light shielding plate A1 is arranged at a position defocused by a predetermined distance D from the field stop 130,
At this position, each sigma luminous flux has a spread rather than a point. Note that here, a normal circular illumination is assumed, and σ
The luminous flux is circular.

In FIG. 20, the distribution of the integrated exposure amount in the X direction when the scanning exposure is performed is obtained by integrating the total energy in the light beam C along a straight line (represented by a dotted line in FIG. 20) defined by each X. Given as an X distribution of values. For example, the exposure amount after scanning exposure at X = 0 is obtained by integrating the total energy in the light flux C along the straight line X = 0 from P0 to P1. Similarly, the exposure amount after scanning exposure at X = X1 is obtained by calculating the total energy in the light beam C along the straight line X = X1.
It is obtained by integrating Q0 to Q1.

Here, comparing the integrated exposure amounts of X = 0 and X = X1, it can be seen that the integrated exposure amount is smaller when X = X1 than when X = 0, by the difference in the light blocking ratio of the light shielding plate A1. Is understood. That is, when the light shielding plate A1 has the predetermined amount D
Even if only defocusing is performed, the strength of the peripheral portion can be reduced by using the light shielding plate A1. That is, it is possible to correct the secondary concave illuminance unevenness by the light shielding plate A1. Here, points other than X = 0, for example, X =
Attention must be paid to the fact that, during scanning exposure, a component in which the σ light beam C is asymmetrically shielded in the X direction occurs during scanning exposure. For example, this is the position of point Q in FIG.

In addition to the point Q, an asymmetric component similar to the point Q is added in a range where the light shielding plate A1 and the σ light beam C intersect. The intensity distribution in the σ light flux C defines the pupil distribution of the illumination. Therefore, the light beam has the asymmetry in the X direction as described above, and if the asymmetry is added, the integrated pupil intensity distribution after the scanning exposure becomes non-uniform in the X direction. Further, if there is such asymmetry in the σ light beam, the position of the center of gravity of the intensity distribution in the σ light beam is shifted from the center Q of the light beam. This is a telecentricity shift. For example, regarding the position of point Q in FIG.
It is clear that the center of gravity of the intensity distribution in the σ light beam blocked by 1 is shifted from the center point Q. This is only for the moment of exposure, but the result of integration along the straight line X = X1 also shows that the direction in which the center of gravity shifts is always constant within the range where the light-shielding plate A1 and the σ beam C intersect. The integrated center of gravity after the exposure deviates from X = X1. That is, a telecentricity deviation occurs.

As described above, the nonuniformity of the pupil intensity distribution (σ
The occurrence of a non-uniform light amount in a light beam) or a telecentricity deviation causes variations in the line width of a pattern to be projected and exposed. To alleviate this problem,
It is desirable that the defocus amount D of 1 be equal to or less than a certain value. This is because, when D is small, the σ luminous flux C becomes small. When the σ light flux C becomes smaller, the inclination of the light shielding portion in the X direction when the σ light flux C intersects the light shielding plate A1 and is shielded becomes smaller. That is, the asymmetry of the intensity distribution in the σ beam in the X direction is relatively reduced. As a result, non-uniformity and telecentricity deviation of the integrated pupil intensity distribution after the scanning exposure are reduced.

In this embodiment, by setting the defocus amount D of the light shielding plate A1 to a value that satisfies the following conditional expressions (1) and (2), the non-uniformity of the light amount distribution in the σ light beam and the telecentricity The deviation can be reduced to within an allowable range.

[0053]

Here, Wx: the length in the longitudinal direction of the exposure field formed on the photosensitive substrate 9, NA _ill : the illumination optical system 1 on the photosensitive substrate side (image side) of the projection optical system 8. The maximum numerical aperture (a value obtained by converting the maximum numerical aperture of the illumination optical system 1 to the photosensitive substrate side (image side) of the projection optical system 8), M: the projection optical system from the predetermined position The imaging magnification up to the imaging plane of 8.

However, in order to change the illumination conditions (coherence factor (σ value) and the annular ratio (the ratio of the outer diameter of the annular light beam to the inner diameter of the annular light beam) in annular illumination, etc., the illumination system is changed. The numerical aperture of the illumination optical system changes in accordance with the size of the light source image (circular light intensity distribution, annular light intensity distribution, multipolar light intensity distribution, etc.) formed on the pupil I do.
Here, the maximum value of the numerical aperture of the illumination optical system 1 defined by NA _ill means the maximum value of the numerical aperture of the illumination optical system that changes with such a change in the illumination conditions. Therefore, NA
_ill is the maximum numerical aperture of the illumination optical system on the image side of the projection optical system (or the illumination optical system converted on the image side of the projection optical system) under illumination conditions indicating the maximum value of the numerical aperture of the illumination optical system. Maximum numerical aperture).

If the upper limits of conditional expressions (1) and (2) are exceeded, it is difficult to sufficiently correct the non-uniformity of the light amount distribution and the telecentricity deviation in the σ light beam.
Further, in order to avoid mechanical interference with the field stop 130, it is desirable that the lower limit value of the distance D is 1 mm or more.

In order to sufficiently obtain the effects of the present invention, it is more preferable that the value of Pj in the above equations (1) and (2) be 0.1 or less and the value of Ps be 0.3 or less. desirable. That is, it is preferable that Pj and Ps in the above equations (1) and (2) satisfy the following equation (3).

Pj ≦ 0.1, Ps ≦ 0.3 (3)

For example, Wx = 25 mm, NA _ill = 0.
6, M = 2, Pj = 0.1 and Ps = 0.3, D = 25.28 mm in conditional expression (1), and D = 47.70 mm in conditional expression (2). Therefore, it is the smaller value that satisfies both the conditional expressions (1) and (2) that is D = 25.28 mm.
Becomes That is, by providing the light shielding plate A1 at a position defocused by D = 25.28 mm from the field stop 130 (reticle conjugate plane), the above-described non-uniformity of the light amount distribution in the σ light beam and the telecentricity deviation can be tolerated. Inside can be smaller.

(Second Embodiment) FIG. 6 is a diagram showing a configuration of an optical system of a projection exposure apparatus according to a second embodiment. In the optical system, a wider variety of illumination modes can be selected with a smaller number of first integrators than in the first embodiment. Therefore, the relay lenses 218 and 222
Has a zoom lens configuration. The same parts as those of the optical system according to the first embodiment are denoted by the same reference numerals, and the description of the overlapping parts will be omitted.

The main difference between the embodiment shown in FIG. 6 and the embodiment shown in FIG. 2 is that three optical integrators are arranged in series, and a zoom optical system is arranged between each optical integrator. Is a point.

The light beam from the light source LS is formed into a desired shape (for example, a square shape) by the beam expander 112, and enters a replaceable diffractive optical element 216a as a first integrator. The first integrator includes a large number of integrated diffraction elements (216a to 216c) having desired divergence angle characteristics and an integration effect.

Specifically, in FIG. 6, a first integrator (first optical integrator) includes a turret plate (not shown) and four turrets held by the turret plate.
And two diffractive optical elements (216a to 216d). Here, a turret plate (not shown) includes a diffractive optical element 216a for annular illumination that converts an incident light beam into an annular light beam, a diffractive optical element 216b for quadrupolar illumination that converts an incident light beam into a quadrupolar light beam, A circular diffractive optical element 216c for ordinary illumination that converts an incident light beam into a circular light beam, and a diffractive optical element 216d for multipolar illumination that converts an incident light beam into a multipolar light beam such as dipole or octupole. The turret plate is rotated by the driving means 40, and an appropriate diffractive optical element is selectively set in the optical path according to the change of the illumination condition. The light beam diffracted by one of the four diffractive optical elements (216a to 216d) in the first integrator is transmitted to the first relay zoom optical system 218 and the second
Integrator 220a, second relay zoom optical system 22
After passing through the light source 2, a desired illumination area is formed on the incident surface of the third integrator 224.

On the exit surface of the third integrator 224, a variable aperture stop 226 corresponding to the illumination area is arranged. The position of the aperture stop 226 forms a secondary light source group. The luminous flux from this secondary light source group is
The field stop 130 is irradiated in a superimposed manner through 28. A light shielding plate A1 is arranged near the field stop 130. Here, the distance D between the light-shielding plate A1 and the field stop 130 is set so that the deviation of the telecentricity and the non-uniformity of the light amount distribution in the σ light beam are not more than a certain value over the entire field of view.
It is determined to satisfy (2). In addition, since the present embodiment assumes a case of a scan type exposure apparatus, the field stop 130 includes a mechanism that moves in synchronization with the scan exposure operation. The field stop 130 is controlled so that unnecessary exposure is not performed throughout the scan exposure. The field stop 130 is provided for the imaging optical system 13.
2 forms an image on the reticle 3.

The reticle 3 is illuminated by the illumination optical system described above, and the circuit pattern drawn on the reticle is projected via the projection optical system 8 onto the resist-coated wafer 9. By scanning the reticle 3 and the wafer 9 synchronously in this arrangement, all the patterns drawn on the reticle 3 are exposed on the wafer 9.

As shown in FIG. 6, driving means 40, 44, 4 are driven by a signal from CPU 38 as control means.
8 is set, one of a number of diffractive optical elements (216a to 216d) as a first integrator is set in the optical path, and the second integrator 220a is set or retracted in the optical path. The shape and size of the opening 226 are appropriately set. The variable aperture stop means 226 includes, for example, a turret plate provided with a large number of aperture stops having different sizes and shapes, which are not shown, and is rotated by the drive means 48 to rotate the turret plate. Third integrator 22
4, the size and shape of the secondary light source (light intensity distribution formed at the pupil position of the illumination optical system) can be accurately defined. In addition, pattern information (fineness, shape or structure of the pattern) of the reticle (mask), exposure process information, and the like are input to the control means 38 as input information via a console (not shown) as input means.
The control means controls the driving means 40, 4 based on the input information.
2, 44, 46 and 48 are controlled.

Next, the operation for changing the illumination condition will be described. For annular illumination, a diffractive optical element 216a for annular illumination is set in the optical path via the driving means 40. Then, the diffractive optical element 116 gives an action of converting incident light into an annular light flux, and the light is transmitted through the diffractive optical element 116 to the first relay zoom optical system 2.
After passing through 18, the incident surface of the fly-eye lens 220a as the second integrator is illuminated with a predetermined numerical aperture. Here, a ring-shaped light intensity distribution is formed on a pupil plane (pupil position of the illumination optical system) PL in the first relay zoom optical system 218.

The second integrator 220a has a large number of lens elements, and the light illuminating the incident surface of the second integrator 220a is divided into wavefronts by the number of lens elements constituting the second integrator 220a. Thereafter, each of the wavefront-divided lights is illuminated via the second relay zoom optical system 222 so as to partially overlap the incident surface of the third integrator 224 in a ring shape, and the incident surface of the third integrator 224 is A ring-shaped illumination region in which substantially ring-shaped light is thickened is formed. Eventually, a secondary light source (or annular light intensity distribution) having an annular shape is formed on the exit side of the third integrator 224 (the pupil position of the illumination optical system). Thus, the mask 3 can be illuminated under the annular illumination condition.

Here, when zooming is performed by moving at least a part of the optical element of the first relay zoom optical system 218 via the driving means 42, the numerical aperture of light incident on the second integrator 220a changes. Further, the annular ratio (the ratio of the outer diameter to the inner diameter of the annular luminous flux) of the annular luminous flux formed on the entrance surface and the exit surface of the third integrator 224 can be made variable. That is, the first relay zoom optical system 218 has a function of changing the ring ratio of the ring light flux.

Further, when zooming is performed by moving at least one optical element of the second relay zoom optical system 222 via the driving means 46, the loop formed on the entrance surface and the exit surface of the third integrator 224. The diameter (outer diameter) of the luminous flux can be made variable. That is, the second relay zoom optical system 222 has a function of changing the diameter (outer diameter) of the annular light flux, in other words, the σ value (coherence factor).

Now, as shown in FIG. 6, a diffractive optical element 216b for quadrupole illumination is set in the optical path via the driving means 40 for quadrupole illumination. Then this 4
The diffractive optical element 216b for polar illumination gives an effect of converting incident light into a quadrupolar light flux, and the diffractive optical element
After passing through the first relay zoom optical system 218, the light having passed through 16b illuminates the entrance surface of a fly-eye lens 220a as a second integrator under a predetermined numerical aperture. Here, on the pupil plane (pupil position of the illumination optical system) PL in the first relay zoom optical system 218, a substantially four-point light intensity distribution is formed.

The second integrator 220a has a large number of lens elements, and the light illuminating the incident surface of the second integrator 220a is divided into wavefronts by the number of lens elements constituting the second integrator 220a. Thereafter, each of the wavefront-divided lights is illuminated via the second relay zoom optical system 222 so as to superimpose the incident surface of the third integrator 224 in a quadrupole shape. Thus, a quadrupole illumination region is formed. Consequently, on the exit side of the third integrator 224 (the pupil position of the illumination optical system), a secondary light source (or 4
A polar light intensity distribution) is formed. Thereby, the mask 3 can be illuminated under the quadrupole illumination condition. Note that the same applies to the case where the diffractive optical element 216d for multipole illumination is set in the optical path, and the description is omitted.

As shown in FIG. 6, for normal illumination (circular illumination), a diffractive optical element 216c for normal illumination (circular illumination) is set in the optical path via a driving means 40, and at the same time, The fly-eye lens 220a as the second integrator is retracted from the optical path via the driving means 44. Then, the diffractive optical element 216c for normal illumination (circular illumination) gives an effect of converting incident light into a circular light beam, and the light passing through the diffractive optical element 216b is used for the first relay zoom optical system 218. And illuminating the entrance surface of the third integrator 224 via the second relay zoom optical system 222 so as to overlap the entrance surface of the third integrator 224 in a circular shape, and a substantially circular illumination area is formed on the entrance surface of the third integrator 224. You. As a result, a secondary light source (or a circular light intensity distribution) having a circular shape as a whole is formed on the exit side of the third integrator 224 (the pupil position of the illumination optical system).
Thus, the mask 3 can be illuminated under the condition of normal illumination (circular illumination). When the magnification of the second relay zoom optical system 222 is changed, the third integrator 22
4, the diameter (outer diameter) of the circular light beam formed on the entrance surface and the exit surface is variable, that is, the σ value (coherence factor)
Can be made variable.

Here, under each illumination condition, at least one magnification change of the first relay zoom optical system 218 and the second relay zoom optical system 222 is performed, depending on the type of pattern formed on the mask and the exposure process. The size and shape of the secondary light source (light intensity distribution) formed on the exit side (pupil position of the illumination optical system) of the third integrator 224 can be appropriately adjusted.

As the first integrator 216a, a fly-eye lens, a microlens array manufactured by etching, an integrated diffractive element or a refractive element having a desired divergence angle characteristic and an integration effect (also manufactured by etching) Etc.) can be used. Further, as the second integrator 220a, a fly-eye lens or a microlens array manufactured by etching can be used. As the third integrator 224, a fly-eye lens or a microlens array manufactured by etching can be used.

FIG. 4B is a view showing a light-shielding pattern of a light-shielding plate A2 serving as a correction filter in the present embodiment. As shown in FIG. 4B, a plurality of light shielding plates A2 are provided.
It is composed of a sub-concave type light shielding pattern group. According to such a configuration as well, in the non-scanning direction (x direction) on the wafer 9, the light shielding amount can be large at both ends of the light shielding pattern, and the light shielding amount can be reduced near the center of the light shielding pattern. For this reason, the light-shielding plate A2 shown in FIG. 4B can correct secondary concave illuminance unevenness.

Further, even in the case of the light shielding plate A2 as in the case of the light shielding plate A1, the non-uniformity of the light amount distribution of the σ light beam and the telecentricity deviation occur as described above. In order to reduce the non-uniformity of the light quantity distribution of the σ light flux and the telecentricity deviation to within an allowable range, the defocus amount D from the field stop 130 (reticle conjugate plane) of the light shielding plate A2 is determined by the above-mentioned conditional expression (1). It is desirable to satisfy (2).

For example, Wx = 25 mm, NA _ill = 0.
6, M = 2, Pj = 0.1 and Ps = 0.3, D = 25.28 mm in conditional expression (1), and D = 47.70 mm in conditional expression (2). Therefore, the conditional expressions (1) and (2) are satisfied.
D = 25.28 mm, which is the smaller value. That is, from the field stop 130 (reticle conjugate plane), D = 25.
By providing the light-shielding plate A2 at a position defocused by 28 mm, the above-described non-uniformity of the light amount distribution and the telecentricity deviation in the σ light beam can be reduced within an allowable range.

In this embodiment, FIG.
Needless to say, a light-shielding plate A1 having a light-shielding pattern as shown in FIG. Also, in the first embodiment shown in FIG. 2, the light-shielding pattern shown in FIG. 4B can be used.

(Third Embodiment) A projection exposure apparatus according to a third embodiment has the same features as the second embodiment, that is,
There is a feature that more various illumination modes can be selected with a smaller number of first integrators than in the first embodiment. As shown in FIG. 7, the optical system of the present embodiment includes the first integrator (2) of the second embodiment.
16a to 216d) and the installation position of the second integrator 220a are reversed. The other configuration is the same as that of the optical system according to the second embodiment, and the description is omitted.

In this embodiment, for example, as a correction filter for correcting secondary concave illuminance unevenness, FIG.
(A), a light shielding plate A1 or A2 having a light shielding pattern as shown in FIG. 4 (b) can be used. Light shield A1
Alternatively, the position where A2 is arranged is a position defocused by a distance D from the field stop 130 (reticle conjugate plane).
It is desirable that the defocus amount D satisfies the conditional expressions (1) and (2).

(Fourth Embodiment) The projection exposure apparatus according to the fourth embodiment is characterized in that a wider variety of illumination modes can be selected with a smaller number of first integrators than in the first embodiment. are doing. As shown in FIG. 8, the third embodiment differs from the second and third embodiments in that an internal reflection type rod integrator 230 is used as the third integrator. On the light source side of the rod integrator 230, an optical system 222a for condensing light from the light source LS to the incident end face of the rod integrator is newly provided. Further, on the reticle side of the rod integrator 230, a relay optical system 22 that guides light from the emission end face of the rod integrator to the condenser optical system 228.
8a are provided. The combined system of the relay optical system 228a and the condenser optical system 228 is an imaging optical system that forms an image of the exit end face of the rod integrator near the field stop 130.

The combinations of elements that can be used as integrators are the same as those of the above embodiments except that the third integrator of the second embodiment is fixed to a rod integrator.

In this embodiment, for example, as a correction filter for correcting secondary concave illuminance unevenness, FIG.
(A), a light shielding plate A1 or A2 having a light shielding pattern as shown in FIG. 4 (b) can be used. Light shield A1
Alternatively, the position at which A2 is arranged is a distance D from the reticle conjugate plane.
Only the defocused position. It is desirable that the defocus amount D satisfies the conditional expressions (1) and (2).

In the first to fourth embodiments, the arrangement in which the imaging optical system 2 is removed is also possible. In that case, the field stop and the light shielding plate A1 or A2 are arranged immediately above the reticle 3. In this arrangement, the value of the magnification M included in the conditional expressions (1) and (2) that determine D is determined by the imaging optical system 2
It is desirable to note that the value is different depending on the amount of the removed.

(Fifth Embodiment) The fifth embodiment shown in FIG. 9 is characterized in that uneven illuminance is corrected by using two light shielding plates A1 and B1. FIG. 9 shows a state from the third integrator 228 to the wafer 9 (substrate) in the embodiment shown in FIGS. As shown in FIG. 9, the light beam from the third integrator 224 passes through the light shielding plate A1, the field stop 130 (movable blind) and the light shielding plate B1 via the condenser optical system 228, and is then applied to the reticle 3 surface by the imaging optical system 2. Be guided. The reticle 3 is illuminated by this light beam, and the pattern on the reticle 3 is transferred to the wafer 9.

The light shielding plate A1 is provided at a first position at a distance D from the field stop 130 (reticle conjugate plane) to the light source LS. Further, the light shielding plate B1 is provided at a second position at a distance D from the field stop 130 (reticle conjugate plane) to the reticle 3 side. Here, the field stop 130 forms a movable blind that moves in synchronization with the movement of the reticle 3 (object surface) and the wafer 9 (image surface). The movable blind is usually located near the reticle conjugate plane. In the present embodiment, the case where the position coincides with the reticle conjugate plane is considered.

FIGS. 10A and 10B are diagrams respectively showing the relationship between the light shielding plates A1 and B1 and the σ light beam in a plane (xy plane) orthogonal to the optical axis AX. Light shielding plates A1, B1
Has a pattern shape for correcting secondary concave illuminance unevenness. This light-shielding pattern is the same as the light-shielding plate A1 used in each of the above embodiments.

Next, the light shielding plates A1 and B1 are
The effect of arranging at the first and second positions equidistant D with respect to 0 (reticle conjugate plane) will be described. First, when only the light shielding plate A1 is arranged on the light source side of the field stop 130 (reticle conjugate plane), the light beam reaching the visual field position Q shown in FIG. 10A is shielded as shown by the hatched portion in the figure. You. This state is shown in FIG. Therefore, similarly to the first embodiment, non-uniformity of the light amount distribution in the σ light beam and deviation of the telecentricity occur.

Here, the light-shielding plate A1 is located at a first position at a distance D from the field stop 130 (reticle conjugate surface) to the light source, and the light-shielding plate B1 is located at a distance from the field stop 130 (reticle conjugate surface) to the reticle side. D at the second position, FIG.
As shown in the figure, the light beam passing through the position a of the light shielding plate A1 is
It passes through the position a of the light-shielding plate B1 which is turned upside down. Position b,
Similarly, the light rays passing through c and d also pass through positions where the top, bottom, left and right are inverted with respect to the light shielding plate A1, respectively. For this reason,
FIG. 5B shows the light quantity distribution of the σ light beam after passing through the two light shielding plates A1 and B1. In this case, the position of the center of gravity of the σ light beam coincides with the position of the center of gravity of the light beam before blocking. Therefore, non-uniformity of the light amount distribution in the sigma luminous flux and telecentricity deviation do not occur.

As described above, as shown in FIG.
And the light-shielding plate B1 are arranged at a position substantially equidistant D from the field stop 130 (reticle conjugate plane), so that the above-mentioned σ
The non-uniformity of the light amount distribution in the light beam and the telecentricity deviation can be eliminated.

In this embodiment, the same effect can be obtained by using a correction filter having a plurality of light shielding patterns as shown in FIG. As described above, the light shielding plate A1 is provided at the first position at the distance D from the field stop 130 (reticle conjugate plane) to the light source LS side. Further, the light shielding plate B1 is provided with a field stop 130 (reticle conjugate plane).
And at a second position at a distance D from the reticle 3 side. As described above, the light-shielding plate A1 and the light-shielding plate B1 are provided at the same distance with respect to the reticle conjugate plane.

However, the present invention is not limited to this, and the two light shielding plates A1 and B1 may not be provided at the same distance.
In this case, when the distance between the light-shielding plate A1 and the reticle conjugate surface is D1, and the distance between the light-shielding plate B1 and the reticle conjugate surface is D2, D included in conditional expressions (1) and (2) is as follows. It is desirable to determine D1 and D2 such that the conditional expression replaced with ΔD defined in Expression (4) is satisfied.

ΔD = | D1-D2 | (4)

This means that the defocus amount when the light shielding plate described in the first to fourth embodiments is provided at a position at a predetermined distance D from the reticle conjugate plane may be replaced by ΔD.

(Sixth Embodiment) In the fifth embodiment,
Two light shielding plates, a light shielding plate A1 and a light shielding plate B1, are used. On the other hand, in the present embodiment, a total of four light-shielding plates are used in order to correct the non-uniformity of the light amount in the σ light beam and the telecentricity deviation with higher accuracy in the scanning direction (Y direction). The points are different. Other configurations are the same as those of the above-described embodiments, and a description thereof will be omitted.

FIG. 12 is a diagram showing an arrangement of four light shielding plates. A pair of light shielding plates A1 are opposed to each other along a first surface PL1 which passes through a first position defocused by a distance D from the field stop 130 (reticle conjugate plane) toward the light source and crosses the optical axis AX of the illumination optical system. A3 is provided. Also, a distance D from the field stop 130 (reticle conjugate plane) to the reticle side
A pair of light shielding plates B1 and B3 are provided so as to face each other along a second surface PL2 passing through the second position defocused only by the optical axis AX of the illumination optical system. For example, the light shielding plate A3 has the same light shielding pattern as the light shielding plate A1, and is provided to face each other. The light-shielding plate B3 also has a light-shielding pattern similar to that of the light-shielding plate B1, and is provided to face each other.

The pair of light shielding plates are provided with a field stop 130
(Reticle conjugate plane) at the same distance D from each other. Similarly to the fifth embodiment, the distance D1 from the field stop 130 (reticle conjugate plane) to the light shielding plates A1 and A3 provided on the light source side, and the distance D1 from the field stop 130 (reticle conjugate plane) to the reticle side. Light shielding plates B1, B provided
The absolute value ΔD of the difference from the distance D2 to 3 (= | D1−D2
D1 and D2 may be determined so that the conditional expression in which |) is substituted for D included in conditional expressions (1) and (2) is satisfied.

Further, as shown in FIG. 12B, the light shielding plates A1 and B1 and light shielding plates A4 and B4 having a linear light shielding pattern can be used. In this case, y
Secondary concave illumination unevenness in the negative direction of the axis, 1 in the positive direction of the y-axis.
The following uneven illuminance unevenness can be corrected. Further, by rotating the light-shielding plates A4 and B4 having the linear light-shielding patterns around the optical axis AX in the first surface PL1 and the second surface PL2, respectively, it is possible to correct a desired primary inclination illuminance unevenness. Can also.

If the illuminance unevenness to be corrected is small, only one of the light shielding plates A1 and B1 may be provided. In this case, by adjusting at least one of the defocus amount D and the rate of change of the curve shape of the light-shielding pattern of the light-shielding plate A1 or B1, non-uniformity of the light amount distribution in the σ light beam and correction of the telecentricity deviation are corrected. It can be carried out.

(Seventh Embodiment) FIG. 13 is a view showing a schematic configuration of an optical system of a projection exposure apparatus according to a seventh embodiment. Here, FIG. 13 shows a state from the third integrator 228 to the wafer 9 (substrate) in the embodiment shown in FIG. 2 and FIG. In the fifth and sixth embodiments,
Shield A with field stop 130 (reticle conjugate plane) in between
1, B1, etc. are arranged. On the other hand, in the present embodiment, the light shielding plate A1 is the first surface PL1 defocused by the distance D1 from the field stop 130 (reticle conjugate surface) toward the light source.
, The light shielding plate B1 has a distance D from the reticle 3 surface to the light source side.
It is provided at the position of the second plane PL2 'defocused by two.

In this arrangement, the condenser optical system 2
Assuming that the angle of the light beam emitted from the field stop 130 (reticle conjugate plane) with respect to 28 is θ1, the angle of the light beam converging on the reticle surface is θ2, and the magnification of the imaging optical system 2 is M, θ2 / θ1 = M To establish. In order to ensure the symmetry of the light amount distribution in the σ light beam in the non-scanning direction (x direction), it is necessary to dispose the light shielding plate A1 and the light shielding plate B1 at positions where the σ light beams become the same.
The size of the σ light beam is given by the defocus amount D × divergence angle θ. Accordingly, the defocus amount D is set so as to satisfy the following equation.
1, D2 may be determined. θ1 × D1 = θ2 × D2

As described above, considering the difference between the divergence angles θ1 and θ2, if the defocus amount is determined so as to satisfy the above expression, the light amount distribution in the σ light beam in the non-scanning direction (x direction) can be obtained. Symmetry can be ensured.

In particular, when it is difficult to arrange the light shielding plate with the reticle conjugate plane interposed therebetween due to the mechanical space,
The arrangement of the light shielding plate of the present embodiment is effective. Further, in the present embodiment, the following three types of light-shielding plate arrangements (a), (b), and (c) can be typically used.

(A) A light-shielding plate A1 having the light-shielding pattern shown in FIG. 4A is provided on both the first surface PL1 and the second surface PL2 '. (B) A light-shielding plate A1 having the light-shielding pattern shown in FIG. 4A is provided on the first surface PL1, and a light-shielding plate A2 having the light-shielding pattern shown in FIG. 4B is provided on the second surface PL2 '. (C) A light-shielding plate A2 having the light-shielding pattern shown in FIG. 4B is provided on both the first surface PL1 and the second surface PL2 '.

As in the fifth embodiment, the distance D1 from the field stop 130 (reticle conjugate plane) to the light shielding plates A1 and A3 provided on the light source side and the reticle surface 3
The absolute value △ D = | D1−M · D2 | in consideration of the magnification M of the imaging optical system 2 is calculated for the distance D2 from the light source to the light shielding plate B1 (B3) provided on the light source side, and the conditional expression ( 1)
D1 and D2 may be determined so that a conditional expression in which the ΔD is substituted for the D included in (2) is satisfied.

In the above-described fifth, sixth, and seventh embodiments, the description has been made by focusing on the optical system from the condenser optical system 228 to the vicinity of the imaging optical system 2. However, any of the first, second, third, and fourth embodiments will be described. The optical system from the condenser optical system 228 to the imaging optical system 2 described in the above is replaced with the optical system from the condenser optical system 228 to the imaging optical system 2 described in any of the fifth, sixth, and seventh embodiments. An arrangement is also possible as an embodiment.

(Ninth Embodiment) Next, a procedure for detecting telecentricity and a procedure for detecting uneven illumination will be described. A procedure for detecting a telecentricity deviation will be described. The telecentricity deviation is a deviation relating to the magnification (hereinafter, referred to as “magnification telecentricity deviation”).
And the shift due to the tilt of the chief ray while keeping the chief rays parallel (hereinafter referred to as “tilt telecentricity shift”).
). The magnification telecentricity deviation can be corrected by defocusing the second fly-eye lens in the optical axis direction. Further, the inclination telecentricity deviation can be corrected by shifting the relay lens in the XY plane orthogonal to the optical axis.

First, on the reticle stage 4, instead of the reticle 3, a dot-like test pattern TP arranged in a square lattice is placed. This test pattern T
P is projected and exposed. Next, a dot pattern printed on the wafer 9 when all the optical systems are ideal is compared with a dot pattern printed using an actual optical system. The control / arithmetic processing unit PC calculates the deviation amount of the telecentricity from the difference between the ideal point image pattern and the actually printed point image pattern.

Next, another procedure for detecting a telecentricity deviation will be described. On the reticle stage 5, a dot-like test pattern TP is placed in the same manner as the above procedure. Then, the control / arithmetic processing unit PC sends a drive signal for moving the reticle stage 5 by a predetermined defocus amount to the drive mechanism DM. The reticle stage 5 is driven in the optical axis Z direction by a driving mechanism DM. Thus, the point-like test pattern TP can be moved to a position defocused by an arbitrary amount. The photoelectric sensor (not shown) converts the grid-like point image of the point-like test pattern TP into a wafer stage 11.
The above is detected photoelectrically. And the detection signal is controlled and
It is sent to the arithmetic processing unit PC. The control / arithmetic processing unit PC
The ideal point image pattern previously stored in the memory unit MU is compared with the detected point image pattern. This makes it possible to detect the amount of deviation in telecentricity.

Next, a procedure for detecting uneven illuminance on the wafer 9 will be described. First, a wafer holder 10 on the wafer stage 11 shown in FIG.
, An illuminance measuring unit 14 is fixed, and a CCD type line sensor 14a (FIG. 14) having a slit-shaped light receiving unit elongated on the upper surface of the illuminance measuring unit 14 in the scanning direction (Y direction).
(See (a)), and the detection signal S2 of the line sensor 14a is supplied to the control / arithmetic processing unit PC. Further, on the upper surface of the illuminance measurement unit 14, a normal illuminance unevenness sensor (not shown) including a photoelectric sensor having a pinhole-shaped light receiving unit is also installed. Although not shown, an exposure area 15 (FIG. 14A) is provided on the wafer stage 11.
A radiation dose monitor with a light receiving unit that covers the whole is also installed,
The detection signal of this dose monitor and the integrator sensor 1
6, a coefficient for indirectly calculating the illuminance on the wafer 9 from the detection signal of the integrator sensor 16 is calculated.

Here, a method of measuring the illuminance unevenness in the non-scanning direction (X direction) of the slit-shaped exposure area 15 using the line sensor 14a will be described with reference to FIG. The measurement of the uneven illuminance is performed, for example, periodically. At that time, the illumination system is switched to the normal illumination, the modified illumination, the small σ value illumination, etc. by driving the aperture stop 126 in FIG. The measurement of the uneven illuminance is performed for each illumination method. Then, the state of uneven illuminance with the elapse of the operation time of the projection exposure apparatus of this example is stored in the storage unit MU as a table for each illumination method.

FIG. 14A shows the wafer stage 1 of FIG.
1 is a diagram illustrating a state in which a line sensor 14a on an illuminance measurement unit 14 is moved to a side surface in a non-scanning direction of an exposure area 15 of a projection optical system 8 by driving a projection optical system 8; The illuminance distribution F (Y) of the exposure region 15 in the scanning direction SD (Y direction) is substantially trapezoidal. As shown in FIG. 14C, the illuminance distribution F (Y)
Assuming that the width of the bottom side of the scanning direction in the scanning direction is DL, the line sensor 1
The width of the light receiving portion 4a in the scanning direction is set sufficiently wider than DL.

Thereafter, the wafer stage 11 is driven to
As shown in FIG. 14A, the line sensor 14 is sequentially moved to a series of measurement points at predetermined intervals in the non-scanning direction (X direction) so as to completely cover the exposure area 15 in the scanning direction. At each measurement point, the exposure light source LS of FIG. 1 emits a pulse, and the detection signal S1 of the integrator sensor 16 and the detection signal S2 of the line sensor 14a are controlled and processed by the processing unit PC
And the detection signal S2 of the line sensor 14a
14B is divided by the digital data of the detection signal S1, the illuminance distribution E (in the non-scanning direction (X) of the exposure area 15 is divided as shown in FIG. X) is calculated. The reason for dividing by the detection signal S1 of the integrator sensor 16 is to eliminate the influence of variations in pulse energy. In this manner, by scanning the line sensor 14a in the X direction, the illuminance distribution E (X) of the exposure region 15 in the non-scanning direction can be measured easily and in a short time. Here, the illuminance distribution E (X) is expressed as a relative value based on the illuminance at the first measurement point at the end in the non-scanning direction, for example.

As a result, the illuminance distribution E (X) represents the illuminance obtained by integrating the illuminance on the exposure area 15 in the scanning direction (Y direction) at each position X in the non-scanning direction. Since each point on the wafer 9 at the time of scanning exposure crosses the trapezoidal area of the illuminance distribution F (Y) in FIG. 14C in the scanning direction, the illuminance distribution E (X) in the non-scanning direction of this example is This is almost equivalent to the distribution of the integrated exposure amount in the non-scanning direction in each shot area on the wafer 9. Then, in this example, the illuminance distribution E (X) can be expressed by the above equation (3) as a function of the position X in the non-scanning direction.

As described above, the illuminance unevenness can be approximated by the second-order polynomial expressed by the above equation (3). The light-shielding pattern of the light-shielding plate has a shape represented by the second-order polynomial. However, when the degree of uneven illuminance is large, approximation of the above equation (3) is insufficient as a light-shielding pattern, and a higher-order component is required.

That is, the illuminance distribution E (X) of the secondary illuminance unevenness on the wafer 9 when the illuminance unevenness is not corrected is represented by the following equation using α as a coefficient.

E (X) = 1 + αX ² (5) Here, the transmission characteristic of the filter for correcting uneven illuminance is represented by t (x).
Then

T (X) × E (X) = k (where k is a constant) (6)

From this, t (X) = k / E (X) = k / (1 + αX ² ) = k (1−αX ² + α ² X ⁴ −...) (7)

Is obtained. Here, the case where the illumination unevenness is large means that α is large. It is necessary to include the expansion order of Expression (7) to a higher order as α increases. That is, even if the illumination unevenness has a quadratic function shape, if the illumination unevenness is large, the transmission characteristic of the correction filter, that is, the shape of the light-shielding pattern requires a second-order or higher order component. .

Note that even when the illumination is discontinued up to the second order, as shown by the sign of the second order term in the equation (7), the second order of the illumination unevenness is obtained.
It should be noted that the sign of the second order coefficient and the second order coefficient of the transmission characteristic (shape of the light shielding pattern) of the correction filter are inverted.

Further, as described below, there are some factors which cause the unevenness of the illumination itself to deviate from the quadratic function shape in the first place. In this case, it is necessary to perform correction using a light-shielding pattern that takes into account higher-order components.

First, when the exposure light is ultraviolet light, the surface of the optical member constituting the illumination optical system or the projection optical system gradually becomes clouded due to the reaction between the organic matter in the atmosphere and the exposure light, and the like. The transmittance of the optical system may decrease in the long term. Further, when the exposure light becomes pulsed light in the vacuum ultraviolet region having a wavelength of about 200 nm or less, the light in the illumination optical system or the projection optical system may be reduced by so-called compaction or the like. It is also known that the refractive member gradually deteriorates and the transmittance thereof gradually changes. Since such a variation in transmittance also depends on the optical path of the exposure light, for example, when the distribution of the exposure light on the pupil plane continues to be non-axisymmetric as in the case of using a so-called modified illumination method, The transmittance variation of the refraction member is also non-axially symmetric, and the illuminance distribution in the illumination area (or the exposure area) becomes non-uniform in the non-scanning direction, and the unevenness of the integrated exposure amount may increase. Further, when the transmittance variation occurs around a point off the optical axis, the telecentricity deviation of the exposure light with respect to the reticle or wafer may exceed the allowable range.

Furthermore, uneven illuminance also occurs due to aging of the anti-reflection film and the like, tolerance of lens components and the like constituting the optical system, and changes in the illumination mode (normal illumination, annular illumination, multipole illumination, etc.). Illuminance unevenness due to these includes components other than the second-order polynomial.

In order to correct illuminance unevenness having various light quantity distributions, for example, a plurality of light shielding plates A5 and A5 having various light shielding pattern shapes as shown in FIG.
6, A7 can be selectively switched. The switching procedure in this case will be described. First, uneven illuminance is detected by the uneven illuminance measuring mechanism described above. The control / arithmetic processing unit PC calculates the coefficients a, b, and c of the above equation (3) from the detected uneven illuminance data by the least square method. Next, the control / arithmetic processing unit PC includes light-shielding plates A5, A5 having an appropriate light-shielding pattern for correcting the uneven illuminance.
6 or A7, and the correction filter switching mechanism FCH
(See FIG. 2). Correction filter switching mechanism F
The CH inserts the light shielding plate selected according to this signal into the optical path. As a result, it is possible to always perform appropriate illumination unevenness correction. The mechanism is not limited to switching between various light-shielding filters, but may be a mechanism in which a plurality of light-shielding plates are prepared, and these can be appropriately replaced.

The primary inclination unevenness component can also be corrected by shifting (eccentric) the light shielding plates A1 and B1 in the x direction by a movable mechanism (not shown). Fine adjustment of other components is also possible by rotating and shifting the light shielding plate in the XY plane.

When uneven illuminance including a higher-order component higher than the secondary component or random illuminance unevenness occurs, it is desirable to correct the illuminance unevenness by using a light-shielding plate having a variable light-shielding pattern shape. In this case, as shown in FIG. 15B, a strip-shaped light shielding pattern element is inserted and removed in the scanning direction (Y direction) by a moving mechanism (not shown). Accordingly, it is possible to form a light-shielding pattern having an arbitrary shape, not limited to the primary component and the secondary component, corresponding to the illuminance unevenness detected by the uneven illuminance measurement mechanism described above.

Next, a method of manufacturing a light shielding plate in the case where the shape of the light shielding pattern is constant will be described. For example, as shown in FIG. 16, a light-shielding plate for correcting secondary concave unevenness in illuminance is formed on a glass substrate GL so as to form a secondary light-shielding pattern.
It is manufactured by vapor deposition. The present invention is not limited to this, and may be manufactured by etching a metal plate into a desired secondary shape.

Further, the method of manufacturing the light-shielding plate described here is not limited to the secondary shape, and can be applied to a light-shielding plate of an arbitrary shape for correcting arbitrary illumination unevenness.

(Tenth Embodiment) FIG. 17 is a flowchart of a semiconductor device manufacturing method for forming a predetermined circuit pattern on a wafer using the exposure apparatus having the projection optical system of each of the above embodiments.

In Step 1, a metal film is deposited on one lot of wafers. In the next step 2,
A photoresist is applied to the metal film on the wafer of the lot. Then, in step 3, using the projection exposure apparatus of FIG. 1 having the projection optical system of the above-described embodiment, the image of the pattern on the reticle R is passed through the projection optical system.
Exposure transfer is sequentially performed on each shot area on the wafers of the lot. Then, in step 4, after the photoresist on one lot of wafers is developed, in step 5, etching is performed on the one lot of wafers using the resist pattern as a mask to correspond to the pattern on the reticle R. Is formed in each shot area on each wafer. Thereafter, a device such as a semiconductor element is manufactured by forming a circuit pattern of an upper layer and the like.

In the projection exposure apparatus according to each of the above-described embodiments, the distance D from the reticle conjugate plane on which the light shielding plate is disposed is limited by the effective diameter of the relay lens and the projection lens, and the pulse characteristics when the light source is an excimer laser. (Discontinuous emission)
It is desirable to optimize in connection with the unevenness due to. Therefore, by making the distance D at which the light shielding plate is arranged variable, it is possible to more optimally correct the illuminance unevenness. Also,
When the degree of uneven illuminance is small, a light shielding plate may be fixedly arranged at a position optimized for each illumination mode.

Also, in any one of the second to tenth embodiments, the field stop 1 is used as in the first embodiment.
The fixed auxiliary stop SB may be arranged at an appropriate position near 30. Further, in the first to tenth embodiments, the present invention can be implemented by using an aperture having a shape in which a light shielding plate for correcting unevenness in exposure and a fixed auxiliary aperture as shown in FIG. 21 are used. is there.

In the present invention, the light restricting member shown in FIG.
The present invention is not limited to the light shielding plates shown in FIGS. The present invention can be applied to any device having the same optical characteristics as the light shielding plate shown in FIGS. 4A and 4B as the performance of the exposure unevenness correction. For example, an element in which light-shielding dots are drawn on a transparent substrate, and the density of the light-shielding dots causes a change in the transmittance in the center and the periphery in the X direction, and a coating in which the transmittance changes continuously is transparent with desired transmittance characteristics. An element coated on a substrate, an element having desired transmittance characteristics by controlling the transmittance of the substrate itself by microfabrication, and the like can be used as the light limiting member of the present invention.

[0136]

As described above, according to the first aspect of the present invention, the light restricting member for adjusting the light intensity distribution of the illumination light is located at a position satisfying the predetermined conditional expressions (1) and (2). Provided. Accordingly, it is possible to provide a projection exposure apparatus having a high illumination uniformity with a small amount of non-uniformity of the light amount distribution in the σ light flux and a small telecentricity deviation with a simple configuration. Claim 2
According to the invention according to the first aspect, the first and second light restricting members are arranged at the first or second position sandwiching a predetermined position (reticle conjugate surface) optically conjugate with the imaging surface of the projection optical system. I have. Accordingly, it is possible to provide a projection exposure apparatus having high illumination uniformity without causing non-uniformity of the light amount distribution in the σ light beam or telecentricity deviation.

According to the third aspect of the invention, the first light restricting member has a pair of first dimming elements, and the second light restricting member has a pair of second dimming elements. This makes it possible to correct illuminance unevenness having various light amount distributions. According to the invention according to claim 4, the first and second light restricting members are provided equidistant from each other with respect to the predetermined position. This makes it possible to correct illuminance unevenness more accurately.

According to the fifth aspect of the present invention, in accordance with the change of the illumination condition, the light restricting member is provided with a predetermined position (reticle conjugate plane) which is optically conjugate with the image forming plane of the projection optical system. Position. Thus, with a simple configuration, it is possible to correct the non-uniformity of the light amount distribution in the σ light beam and the telecentricity deviation due to the change of the illumination condition, and to provide a projection exposure apparatus having high illumination uniformity. According to the method for manufacturing a micro device of the invention, there is provided a step of projecting an image of a pattern of a mask via the projection exposure apparatus according to the invention. Thereby, a micro device having a highly accurate circuit pattern can be manufactured. Also, the yield of products can be improved.

According to the micro device manufacturing method of the invention, the predetermined position (reticle conjugate plane) optically conjugate with the image forming plane of the projection optical system according to the change of the illumination condition.
Alternatively, the method includes a step of adjusting the light intensity distribution of the illumination light using a light restricting member disposed at a position near the light restricting member. Thus, with a simple configuration, it is possible to correct the non-uniformity of the light amount distribution in the σ light beam and the telecentricity deviation due to the change of the illumination condition, and to manufacture a micro device having a highly accurate circuit pattern. Also, the yield of products can be improved. According to the invention of claim 8, since the light intensity distribution on the photosensitive substrate such as a wafer is adjusted by the light restricting member, the unevenness in the exposure amount on the photosensitive substrate can be corrected, and a good mask without yield can be obtained. The pattern of the reticle can be transferred, so that a good microdevice can be manufactured.

[Brief description of the drawings]

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

FIG. 2 is a diagram illustrating a configuration of an optical system of the projection exposure apparatus according to the first embodiment.

FIGS. 3A, 3B, and 3C are diagrams illustrating types of uneven illuminance. FIGS.

FIGS. 4A and 4B are diagrams showing examples of a light shielding plate.

FIGS. 5A and 5B are diagrams showing a relationship between a σ beam and a light shielding area.

FIG. 6 is a diagram illustrating a configuration of an optical system of a projection exposure apparatus according to a second embodiment.

FIG. 7 is a diagram illustrating a configuration of an optical system of a projection exposure apparatus according to a third embodiment.

FIG. 8 is a diagram showing a configuration of an optical system of a projection exposure apparatus according to a fourth embodiment.

FIG. 9 is a diagram illustrating a configuration around a light shielding plate of an optical system according to a fifth embodiment.

FIGS. 10A and 10B are diagrams showing a light-shielding pattern and a σ beam.

FIG. 11 is a diagram showing a relationship between two light shielding plates in a fifth embodiment.

FIGS. 12A and 12B are diagrams illustrating a relationship between four light shielding plates according to a sixth embodiment.

FIG. 13 is a diagram illustrating a configuration of an optical system around a light shielding plate according to a seventh embodiment.

14A is a configuration of a sensor that detects uneven illuminance, FIG.
(B), (c) is a figure which shows an illuminance distribution.

FIG. 15A is a diagram illustrating a configuration of a switchable light shield having various light shield patterns, and FIG. 15B is a diagram illustrating a configuration of a light shield having a variable light shield pattern.

FIG. 16 is a diagram relating to the manufacture of the light shielding plate.

FIG. 17 is a diagram illustrating a method for manufacturing a micro device.

FIGS. 18A and 18B are diagrams illustrating a deformed opening.

FIG. 19 is a diagram showing a configuration of a fixed auxiliary aperture.

20 is a diagram showing a state near a light shielding plate when the fixed auxiliary aperture shown in FIG. 19 is used.

FIG. 21 is a diagram showing a state of a diaphragm having a shape obtained by combining a light shielding plate and a fixed auxiliary diaphragm.

[Explanation of symbols]

LS: light source, 1: illumination optical system, 1A: illumination unit,
2 ... Relay optical system (imaging optical system), 3 ... Reticle, 4 ...
Reticle holder, 5 reticle stage, 6 reticle moving mirror, 7 interferometer, 8 projection optical system, 9 wafer, 1
0: Wafer holder, 11: Wafer stage, 12: Wafer moving mirror, 13: Interferometer, 14: Line sensor, PC
Operation / processing unit, CNS: console, MU: storage unit, 1
12: beam expander, 114, 134: reflecting mirror,
118, 128: turret, 116, 124: integrator, 126: aperture stop, FCH: filter switching mechanism, A1 to A7, B1 to B4: light shielding plate, 130: field stop (reticle conjugate plane), 228: condenser optical system

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shigeru Hiragawa 3-2-3 Marunouchi, Chiyoda-ku, Tokyo Nikon Corporation F term (reference) 5F046 BA05 CB01 CB05 CB10 CB12 CB23 CC01 CC02 DA01 DA02 DA11 DB01 DC12

Claims (8)

[Claims] An illumination optical system for illuminating a mask on which a predetermined pattern is formed, and a projection optical system for projecting and exposing a pattern image of the mask illuminated by the illumination optical system on a photosensitive substrate. A scanning device that scans the mask and the photosensitive substrate with respect to the projection optical system, wherein the illumination optical system sandwiches a predetermined position optically conjugate with an imaging plane of the projection optical system. A light limiting member for adjusting the light intensity distribution of the illumination light at at least one of the light source side and the mask side, wherein the light limiting member has a distance D from the predetermined position to the light limiting member is as follows: A projection exposure apparatus, which is arranged in an illumination light path so as to satisfy a condition. Here, Wx: the length in the longitudinal direction of the exposure field formed on the photosensitive substrate, NA _ill : the maximum value of the numerical aperture of the illumination optical system on the photosensitive substrate side of the projection optical system, M: An imaging magnification from a predetermined position to an imaging plane of the projection optical system. 2. An illumination optical system for illuminating a mask on which a predetermined pattern is formed, and a projection optical system for projecting and exposing a pattern image of the mask illuminated by the illumination optical system onto a photosensitive substrate. A scanning device that scans the mask and the photosensitive substrate with respect to the projection optical system, wherein the illumination optical system sandwiches a predetermined position optically conjugate with an imaging plane of the projection optical system. And a first light restricting member disposed at a first position on the light source side and a second light restricting member disposed at a second position on the mask side, wherein the first and second light restricting members are illuminated. A projection exposure apparatus for adjusting a light intensity distribution of light. 3. The first light limiting member has a pair of first dimming elements provided to face each other along a first surface passing through the first position and crossing an optical axis of the illumination optical system. The two-light limiting member includes a pair of second dimming elements provided to face each other along a second surface passing through the second position and crossing an optical axis of the illumination optical system. The projection exposure apparatus according to claim 1. 4. The projection exposure apparatus according to claim 2, wherein the first light restricting member and the second light restricting member are arranged at an equal distance from each other with respect to the predetermined position. 5. An illumination optical system for illuminating a mask on which a predetermined pattern is formed, and a projection optical system for projecting and exposing a pattern image of the mask illuminated by the illumination optical system on a photosensitive substrate. A scanning device that scans the mask and the photosensitive substrate with respect to the projection optical system, wherein the illumination optical system changes a lighting condition with respect to the mask, and an illumination condition by the changing device. A light limiting member that adjusts the light intensity distribution of the illumination light at at least one of the light source side and the mask side across a predetermined position optically conjugate with the image forming plane of the projection optical system in accordance with the change of A projection exposure apparatus characterized by the above-mentioned. 6. A step of applying a photosensitive material onto a substrate, and a step of projecting an image of the pattern of the mask onto the substrate via the projection exposure apparatus according to any one of claims 1 to 5. A method of developing the photosensitive material on the substrate; and a step of forming a predetermined circuit pattern on the substrate using the developed photosensitive material as a mask. 7. An illumination step of illuminating a mask on which a predetermined pattern is formed using an illumination optical system, and said mask and said photosensitive element are projected to a projection optical system for projecting a pattern image of said mask onto a photosensitive substrate. A scanning exposure step of scanning and exposing a pattern image of the mask on the photosensitive substrate by scanning a substrate, wherein the illumination step includes: a changing step of changing illumination conditions for the mask; and an illumination condition by the changing step. Including an adjusting step of adjusting the light intensity distribution of the illumination light using a light restricting member disposed at or near a position optically conjugate with the imaging plane of the projection optical system according to the change of Of manufacturing micro devices. 8. The method according to claim 7, wherein in the adjusting step, the light intensity distribution on the photosensitive substrate is adjusted by the light restricting member in order to correct the exposure amount unevenness on the photosensitive substrate. 3. The method for manufacturing a microdevice according to item 1.