JPH05259020A - Projection aligner - Google Patents

Abstract

PURPOSE:To make an illumination optical system small in size by a method wherein, when various types of measurements are conducted using the reference members on a substrate stage, the light generated by a reference pattern is guided to a detection means by deflecting the light outside the optical path of an illumination optical system by a deflection member in a plane perpendicular to the optical axis of the illumination optical system. CONSTITUTION:A deflection member 11 is constituted in such a manner that it can be retreated from the light path of an illumination optical system by a motor 12, and the deflection member 11 is retreated to outside the illumination light path so that the illumination light, which will be projected on a reticle, is not obstructed when a pattern exposing operation is conducted on a wafer 21. The deflection member is arranged in the illumination light path only when various types of measurements are conducted using a reference member 20. At this time, the taking in and out of the deflection member 11 to the illumination light path is conducted almost along the direction perpendicular to the optical axis of the illumination optical system. A photoelectric detector 15 outputs a photoelectric signal which is corresponding to the quantity of light of the transmitted light SL which is deflected by the deflection member 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection exposure apparatus used for patterning semiconductor integrated circuits, liquid crystal devices and the like.

[0002]

2. Description of the Related Art In a projection exposure apparatus (eg, stepper) used in a photolithography process for manufacturing a semiconductor device, an image of a circuit pattern to be transferred drawn on a reticle (mask) is transferred to a substrate via a projection optical system. An image is projected on the (wafer). The wafer is placed on a wafer stage that is two-dimensionally movable, and a reference member (glass substrate) having a reference mark (fiducial mark) is arranged on the wafer stage so that the reference member (glass substrate) substantially matches the wafer surface. It is provided. This fiducial mark is disclosed, for example, in JP-A-59-94032 and JP-A-1-262624.
As disclosed in Japanese Patent Laid-Open Publication No. 1989-331, for reticle alignment, imaging characteristics of a projection optical system, alignment marks on a reticle performed before an exposure operation, or reticle alignment mark detection marks arranged above the reticle. It is used for measuring the relative distance (baseline) between the mark detection position of the sensor and the mark detection position of the sensor for wafer alignment mark detection of the TTL method or the off-axis method.

As the fiducial mark, for example, a reflection type mark formed by patterning chrome on quartz glass is used, and the mark detection position is obtained by detecting the mark with an alignment sensor. Alternatively, there is a method in which the fiducial mark is a light transmission type slit mark and a light amount sensor is provided below it (on the wafer stage side), or a light amount sensor having the fiducial mark itself as a light receiving surface is used. In these methods, the reticle mark and the mark detection position of the alignment sensor are obtained from the amount of light received by the light amount sensor (the image of the reticle mark, the amount of illumination light flux of the alignment sensor).

However, when the image of the reticle mark is detected by the light amount sensor, the illumination optical system (exposure illumination optical system) that illuminates the reticle mark illuminates not only the mark portion but also a wide area. Light from other than the mark portion on the reticle reaches the mark (for example, a slit pattern) as flare, which may reduce the measurement accuracy. Therefore, for example, JP-A-64-10
As disclosed in Japanese Patent Laid-Open No. 105-105, a light emitting type fiducial mark is used, that is, the fiducial mark is irradiated by the exposure illumination light transmitted to the bottom of the reference member by an optical fiber, a mirror or the like, and the lower surface of the reticle ( A method has been proposed in which the transmitted light amount of illumination light that has passed through the reticle mark is detected in the illumination optical system by moving the projection image formed on the pattern surface) and the reticle mark relatively.

By the way, the light quantity sensor for detecting the transmitted light must not block the exposure illumination light with which the reticle is irradiated. Therefore, conventionally, a beam splitter (half mirror) is provided in the illumination optical system and the reticle is provided. The illumination light transmitted through the mark is configured to be guided to the light amount sensor arranged outside the illumination optical path. Therefore, in the illumination optical system of the conventional device, several tens of centimeters are required to install this half mirror.
The lens space (space) was necessary. In particular, regardless of where the reticle mark is placed (formation position),
In order to always detect the transmitted light of the reticle mark with the same arrangement (configuration), it was necessary to arrange a half mirror near the Fourier transform surface with respect to the reticle pattern surface in the illumination optical system.

[0006]

Recently, as a method of improving the resolution and the depth of focus of a projection optical system, attention has been paid to an annular illumination and a modified light source. This is to tilt the illumination light incident on the reticle pattern by a specific angle. Therefore, an illumination optical system in which the numerical aperture of the illumination optical system (sine of the angle of incidence of the illumination light beam on the reticle) is much larger than that of the conventional device is required. Such an illumination optical system having a large numerical aperture is difficult to design and manufacture, and it is inevitable to increase the size and cost of the entire apparatus. In particular, the space (lens interval) for the half mirror as described above becomes a factor in further increasing the size of the illumination optical system.

The present invention has been made in view of the above problems, and can be applied to new exposure techniques such as an annular illumination method and a modified light source method, and can also be applied to various measurements using conventional reference marks as they are. It is an object of the present invention to provide a projection exposure apparatus equipped with a compact, low-cost illumination optical system.

[0008]

In order to solve such a problem, in the present invention, the light generated from the reference pattern is arranged in a plane substantially perpendicular to the optical axis of the illumination optical system, and the light generated by the reference pattern is emitted from the illumination optical system. A light beam deflecting member for deflecting the light beam out of the optical path is provided, and the light from the reference pattern deflected here is detected. In addition, a substrate which is arranged in a plane substantially perpendicular to the optical axis in the illumination optical system and is substantially transparent to the illumination light, and a mask side with respect to this substrate are arranged so that the light generated from the reference pattern is transmitted to the transparent substrate. A light beam deflecting member for inclining the light to enter is provided, and the light from the reference pattern propagating inside the substrate and guided to the outside of the optical path of the illumination optical system is detected.

[0009]

In the present invention, when performing various measurements (position measurement of the alignment mark of the mask, etc.) using the reference member on the substrate stage, the light beam deflection arranged in the plane perpendicular to the optical axis of the illumination optical system. The member deflects the light generated from the reference pattern out of the optical path of the illumination optical system and guides it to the detection means. Therefore, the illumination optical system may be small, and various measurements using the reference member can be performed as in the conventional case. On the other hand, at the time of exposure, since the light beam deflecting member is removed from the optical path of the illumination optical system, it does not have any adverse effect on the exposure illumination light that should be applied to the mask. In particular, the light beam deflecting member may be a flat plate having a thickness of, for example, about several mm, and it is not necessary to provide a large gap between the optical elements forming the illumination optical system.

[0010]

1 is a diagram showing a schematic construction of a projection exposure apparatus according to an embodiment of the present invention. In FIG. 1, illumination light emitted from a light source 1 such as a mercury lamp is reflected by an elliptical mirror 2, and then a relay lens via a folding mirror 3, a relay lens 4, a shutter 5, a relay lens 7, and a folding mirror 8. The (input lens) 9 collimates the light beam and makes it enter the optical integrator (fly-eye lens) 10. The fly-eye lens 10 is for uniformizing the illuminance (intensity distribution) of the illumination light flux on the pattern surface of the reticle 17, and the reticle side (emission surface side) focal plane of the fly eye lens 10 is the optical surface with respect to the pattern surface of the reticle 17. A Fourier transform plane (hereinafter referred to as the pupil plane of the illumination optical system),
Alternatively, it is arranged in the plane in the vicinity thereof.

The illumination light emitted from the fly-eye lens 10 illuminates the circuit pattern formed on the lower surface side of the reticle 17 by the condenser lens group 16. Here, as the condenser lens group 16, an optical system that is highly aberration-corrected in order to make the intensity distribution of the illumination light flux uniform is used. On the reticle 17, a reticle mark 18 is drawn along with the circuit pattern along with the circuit pattern. The light transmitted through the reticle 17 and diffracted is projected by the projection optical system 19.
The light is focused and imaged on the wafer 21 to form a circuit pattern image. In FIG. 1, the reference member 20 is arranged at the projection position of the reticle mark 18.

The wafer 21 is placed on a wafer stage 22 which can move two-dimensionally on a pedestal 23, and the surface of the wafer 21 is projected by the projection optical system 1.
The position of the wafer stage 22 is measured by a laser interferometer 28. At the end of the wafer stage 22, a reflecting mirror (moving mirror) 2 that reflects the laser beam from the laser interferometer 28.
4 is fixed.

Further, a reference member (a glass substrate such as quartz) 20 having a reference mark (fiducial mark) FM is provided on the wafer stage 22, as disclosed in, for example, Japanese Patent Laid-Open No. 1-262624. It is provided so as to substantially coincide with the surface of the wafer. Optical fiber 26
Guides the exposure illumination light (or a part) emitted from the light source 1 to below the reference member 20, and the illumination light is transmitted through the lens system 25.
The reference mark FM is irradiated from below (inside the wafer stage 22) via. The reference mark FM is a light transmissive slit mark, and the light transmitted through the reference mark FM forms a projected image of the reference mark FM on the pattern surface of the reticle 17 via the projection optical system 19. In addition, reticle 1
After passing through the condenser lens group 16, the light SL that has passed through 7 is deflected by the deflecting member 11 arranged in a plane substantially perpendicular to the optical axis of the illumination optical system, and is photoelectrically arranged outside the optical path of the illumination optical system. It is incident on the detector 15.

The deflecting member 11 is constructed so that it can be retracted from the optical path of the illumination optical system by the motor 12 so as not to block the illumination light emitted to the reticle 17 when the pattern exposure is performed on the wafer 21. Then, the deflecting member 11 is retracted out of the illumination optical path. Alternatively, the deflecting member 11 is arranged in the illumination optical path only when performing various measurements using the reference member 20. At this time, the deflecting member 11 is moved in and out of the illumination optical path substantially along the direction perpendicular to the optical axis of the illumination optical system. This operation is performed based on a command from the main control system 29. The specific configuration of the deflecting member 11 will be described in detail later.

By the way, the photoelectric detector 15 includes the deflecting member 11
A photoelectric signal corresponding to the light amount (intensity) of the transmitted light SL deflected by is output to the main control system 29. This photoelectric signal changes according to the position of the wafer stage 22, that is, the relative positional relationship between the reticle mark 18 and the projected image of the reference mark FM formed on the lower surface of the reticle 17. For example, if the reticle mark 18 is a slit mark having a light-transmitting portion formed in the light-shielding portion, the level of the photoelectric signal becomes maximum when the two accurately match. Therefore, based on the level change of the photoelectric signal from the photoelectric detector 15, the reticle mark 18
The relative positional relationship between the reference mark FM and the reference mark FM, that is, the position of the reticle mark 18 (coordinate value in the coordinate system defined by the interferometer 28) is obtained. Main control system 2
9 inputs the position signal from the laser interferometer 28 together with the photoelectric signal from the photoelectric detector 15, and calculates the position (coordinate value) of the reticle mark 18 using these two signals.

Further, in FIG. 1, an off-axis type alignment sensor 30 is provided. The alignment sensor 30 employs an image processing method, and an alignment mark or reference mark FM on the wafer 21 and an index mark fixed in a plane conjugate with the wafer surface are simultaneously obtained by an image pickup device (CCD camera or the like). By observing, the displacement of the alignment mark or the like with respect to the index mark is detected. The main control system 29 calculates the positions (coordinate values) of the alignment mark and the reference mark based on the positional deviation information from the alignment sensor 30 and the positional information from the interferometer 28. The alignment sensor 30
The position when the fiducial mark FM is detected by the sensor 30
Mark detection position. At this time, the reference mark FM has only to act as a reflection type mark, and it is not necessary for the mark FM itself to emit light. As described above, the reference mark FM
The distance (distance) between the position of the reticle mark measured by using and the mark detection position of the alignment sensor 30 is the baseline amount.

Next, the deflecting member applied to this embodiment will be described with reference to FIG. FIG. 2A shows the lower surface of the parallel plate (glass substrate such as quartz) 11A which is almost transparent to the exposure illumination light (the surface on the side of the reticle 17 when placed in the optical path of the illumination optical system). Micro prism 11
B is formed. The illumination light SL generated from the reference mark FM that has passed through the reticle 17 without being blocked by the reticle mark 18 is refracted by the microprism 11B and is incident on the parallel plate 11A at an angle. Further, by repeating internal reflection inside the parallel plate 11A and propagating inside the parallel plate 11A, the light is guided to the outside of the optical path of the illumination optical system, emitted from the end face of the parallel plate 11A, and then received by the photoelectric detector 15. Become.

The deflecting member shown in FIG. 2 (a) is thin in itself, and is arranged substantially perpendicular to the optical axis of the illumination optical system. Further, by utilizing the internal propagation of the parallel plate 11A, the illumination is performed. It is possible to guide the light SL in a direction substantially perpendicular to the optical axis of the illumination optical system (direction along the substrate surface). Therefore, the space in which the deflecting member 11 is to be arranged, that is, the distance between the fly-eye lens 11 and the condenser lens group 16 can be narrowed, and the illumination optical system can be downsized.

In FIG. 2B, the diffraction grating 11C is formed on the lower surface of the parallel plate 11A. The illumination light SL diffracted by the diffraction grating 11C propagates inside the parallel plate 11A, is guided to the outside of the illumination light path, is emitted from the end face thereof, and is incident on the photoelectric detector 15 just as in FIG. It will be. The pitch of the diffraction grating 11C may be arbitrary. Further, the diffraction grating 11C may be a phase type or an amplitude type, and may be anything as long as it diffracts (scatters) the illumination light SL including a Fresnel zone plate and the like. Although the transmission type diffraction grating 11C is used in FIG. 2B, a reflection type diffraction grating may be used. In this case, it is necessary to form a reflection type diffraction grating on the upper surface of the parallel plate 11A (the surface opposite to the reticle 17).

In FIG. 2C, the lower surface of the parallel plate 11D is sandblasted to scatter the illumination light SL. In FIG. 2C as well, as in FIGS. 2A and 2B, the illumination light SL scattered on the lower surface propagates inside the parallel plate 11D and is guided to the outside of the illumination optical path. The upper surface of the parallel plate 11D may be sandblasted, and the light scattered here and returning to the reticle 17 side may be internally reflected inside the parallel plate 11D. Also, FIG.
In the deflecting members shown in (b) and (c), light diffracted or scattered on the lower surface (or upper surface) is emitted from each of the left and right end surfaces of the parallel plate, so that two sets of photoelectric detectors are used. It may be arranged corresponding to each end face and, for example, one obtained by adding the respective outputs may be used.

In FIG. 2, the illumination light SL is deflected (diffracted, scattered) by a deflecting member formed on the lower surface (the surface on the reticle side) of the parallel plate, and the internal reflection is utilized by inclining the incident light SL to enter the parallel plate. However, any member that deflects the illumination light may be used. In addition, the deflecting member 11
The angle of deflection of the illumination light SL (the inclination angle of the illumination light incident on the parallel plate) and the thickness of the parallel plate may be arbitrary, and the point is that the illumination light may be internally reflected in the parallel plate. Further, a light-shielding layer may be formed on the entire upper surface (the surface opposite to the reticle) of the parallel plate to reduce the loss of the amount of light incident on the photoelectric detector 15. Further, the deflecting member 11 may be slightly tilted with respect to the optical axis of the illumination optical system, and depends on the space in which the deflecting member 11 is to be arranged (the distance between the fly-eye lens 10 and the condenser lens group 16 in FIG. 1). In order to reduce the light amount loss as much as possible, the deflecting member 11 may be positively tilted with respect to the optical axis. Further, even if the fluorescent substance provided on the lower surface of the parallel plate is irradiated with the illumination light SL and the fluorescence (or phosphorescence) generated here is detected by the photoelectric detector 15, the same effect as above can be obtained. be able to.

As described above, the deflecting member in this embodiment is
In both cases, the thickness of the parallel plate may be about several millimeters, so that the restrictions on the illumination optical system are greatly relaxed compared with the conventional one.
By the way, the position where the deflecting member 11 is to be arranged may be anywhere in the illumination optical system, but it is desirable to be within the optical Fourier transform plane for the reticle pattern plane in the illumination optical system or in the plane in the vicinity thereof. .. This is because when the deflecting member 11 is arranged near the Fourier transform surface, the illumination light flux from the reticle mark 18 (reference mark FM) is always at the same position on the deflecting member 11 regardless of the position where the alignment mark is formed on the reticle. It is to reach. Therefore, the deflection member 11 can be small, and the same position on the deflection member 11 is always used.
1B, 11C, etc.) has the advantage that non-uniformity of the shape or the like depending on the location does not give an error to the measurement of the reticle mark. In FIG. 1, the deflecting member 1 is provided near the exit surface (Fourier transform surface) of the fly-eye lens 10 that satisfies the above conditions.
1 was placed. It is not necessary to form the diffraction grating 11C or the like on the entire lower surface of the parallel plate 11A, and for example, only the portion of the light from the reticle mark 18 that corresponds to the region irradiated with the 0th-order light is diffracted. The grid 11C or the like may be formed.

Further, a relay lens system may be provided between the exit surface of the fly-eye lens 10 and the deflecting member 11 so that they are connected in an image forming relationship. At this time, the fly-eye lens 10
Both the exit surface and the deflection member 11 are arranged near the Fourier transform surface of the reticle pattern. When such a relay lens system is used, a conjugate plane with the reticle pattern surface is formed in the relay lens system, so that a field stop or the like can be provided here.

The deflecting member shown in FIG. 2 is a parallel plate 1
Micro prism 11B and diffraction grating 11C on the lower surface of 1A
Etc. were formed, but as shown in FIG.
For example, the diffraction gratings 11E and 11H may be arranged at a predetermined distance in the optical axis direction. FIG. 3A shows an example using a transmission type diffraction grating 11E. The light diffracted here is incident on the parallel plate 11A with an inclination, propagates inside the same, and is guided to the outside of the illumination optical path. Become. FIG. 3B shows an example using a reflection type diffraction grating 11H, which is a parallel plate 11A.
The illumination light SL that has passed through is diffracted by the diffraction grating 11H, is then incident again while being inclined with respect to the parallel plate 11A, propagates through the inside thereof, and is guided to the outside of the illumination optical path. Figure 3
Also in (a) and (b), the photoelectric detector 15 is a parallel plate 11A.
Is arranged close to the end face of the.

Further, for example, in JP-A-1-262624 and JP-A-1-273318, the light generated from the reference mark FM is divided into two in the pupil plane (Fourier transform plane) of the illumination optical system, and this division is performed. A technique for detecting the focal position of the projection optical system by individually detecting the emitted light is disclosed. The same effect can be obtained by directly applying the present invention to a device that splits a light beam into two in the pupil plane of the illumination optical system as described above. That is, in the device disclosed in the above publication, a deflecting member as shown in FIG. 4A may be arranged near the pupil plane of the illumination optical system. FIG. 4A shows a parallel plate 1.
Two sets of micro prisms 11F ₁ and 11F on the lower surface of 1A
Formed ₂ . FIG. 4B shows a state in which FIG. 4A is viewed from the reticle side, and the illumination light SL is refracted by each of the micro prisms 11F ₁ and 11F ₂ , and the boundary between the prisms 11F ₁ and 11F ₂ is shown. 2 as division line
It is divided, and the internal reflection is repeated in the left-right direction on the paper surface. Therefore, the parallel plate 11A
If two sets of photoelectric detectors are arranged so as to correspond to the left and right end faces of, the focal position of the projection optical system can be obtained in exactly the same manner as in the above publication.

FIG. 5 shows an example of a deflecting member which is effective in reducing the light quantity loss of the light beam incident on the photoelectric detector. The parallel plate 11A has an upper surface (a surface opposite to the reticle) a light shielding layer over the entire surface. An LSB (chromium or the like) is formed. on the other hand,
A light-shielding layer LSB is formed on the lower surface of the parallel plate 11A except for an area of the illumination light SL transmitted through the reticle 17, which is particularly irradiated with 0th-order light, and the transmission type diffraction grating is provided in the irradiation area. 11G is formed. For this reason,
While the internal reflection is repeated in the parallel plate 11A, there is no light to be emitted to the outside, and all the light diffracted by the diffraction grating 11G and incident on the parallel plate 11A has two sets of photoelectric detectors 1.
The light is received by 5a and 15b. Therefore, a sharp signal waveform can be obtained by adding and using the outputs of the two sets of photoelectric detectors 15a and 15b, and the measurement accuracy can be improved. It should be noted that the photoelectric detector may be one set, and in this case, the parallel plate 11 in which the photoelectric detector is not arranged is arranged.
It is preferable to form a light-shielding layer also on one end surface of A.

FIG. 6 shows an example in which only a parallel plate 11A tilted by a predetermined angle with respect to the optical axis of the illumination optical system is used as the deflecting member. The upper and lower surfaces of the parallel plate 11A are shielded from light. The layer LSB is formed. Parallel plate 1
The tilt angle of 1A may be determined according to the space of the illumination optical system (the distance between the fly-eye lens 10 and the condenser lens group 16 in FIG. 1).

In the above embodiment, the distance (in the direction of the optical axis) between the two sets of optical elements sandwiching the deflecting member is shortened by utilizing the internal reflection inside the parallel plate. In other words, the two sets of optics are arranged. The deflecting member can be arranged even if the distance between the elements is small. However, depending on the distance between the two sets of optical elements sandwiching the deflecting member, for example, only a transmission type or reflection type diffraction grating (duty ratio 1: 1) is arranged in the optical path of the illumination optical system without using a parallel plate. I don't care. At this time, the grating pitch is set so that the light diffracted by the diffraction grating (first-order diffracted light) is not eclipsed by the adjacent optical element (the fly-eye lens 10 in FIG. 1), and the photoelectric detector receives the first-order diffracted light. Good. Further, the second-order diffracted light may be received by the photoelectric detector by changing the duty ratio of the diffraction grating, for example, by setting it to 1: 3. Furthermore, a diffraction grating (see FIG. 2) is used for liquid crystal display elements and electrochromic elements.
(11C in (b)) and if the diffraction grating is formed only when measurement is performed using the reference mark, it is not necessary to move the diffraction grating plate (deflecting member) in and out of the illumination optical path.

The present invention is also applicable to a system in which the reference mark is a reflection type, the exposure illumination light is applied to the reference mark from the reticle side, and the light reflected here is photoelectrically detected through the reticle. Can be applied. At this time, the relative positional relationship between the reticle mark and the wafer mark can also be obtained by irradiating the alignment mark on the wafer with illumination light instead of the reference mark.

Further, when adopting the annular illumination method or the modified light source method, the illumination light from the light source 1 (the secondary light source of the fly-eye lens 10) has a predetermined angle range and is with respect to the optical axis AX. It is necessary to provide a light beam conversion member that converts the light beam into at least one light beam that is inclined and incident on the reticle pattern. The luminous flux conversion member distributes the intensity distribution of the illumination light in the pupil plane of the illumination optical system in at least one region not including the optical axis AX (however, in the annular illumination method, an annular shape centered on the optical axis AX is used. The area is limited to, for example, a diaphragm (spatial filter) arranged near the pupil plane (emission surface of the fly-eye lens 10) of the illumination optical system is used. As the light flux conversion member, an optical fiber, a polyhedral prism (or a cone prism), a mirror, etc. may be used in addition to the diaphragm. Especially, when a diaphragm is used, reflection type diffraction is performed in the central portion (area near the optical axis). A grating or the like may be provided and the light reflected here may be inclined and incident on the parallel plate.

A folding mirror may be arranged between the fly-eye lens 10 and the reticle 17 in the apparatus shown in FIG. Even in this case, since the folding mirror may be near the reticle, the design of the illumination optical system is easier and the size can be reduced as compared with the conventional case where the half mirror is arranged near the Fourier transform surface.

[0032]

As described above, according to the present invention, even in the projection exposure apparatus that detects the illumination light from the reference mark that has passed through the mask through a part of the illumination optical system, there are restrictions on the illumination optical system. Can be significantly reduced, and a compact and low-cost illumination optical system can be realized. In addition, even for the illumination optical system with a large numerical aperture for the annular illumination and the modified light source, which have recently received attention,
Various highly accurate measurements can be realized.

[Brief description of drawings]

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

FIG. 2 is a diagram showing an example of a specific configuration of a deflecting member in FIG.

FIG. 3 is a diagram showing another example of a deflecting member suitable for the projection exposure apparatus shown in FIG.

FIG. 4 is a view showing another example of a deflecting member suitable for the projection exposure apparatus shown in FIG.

5 is a view showing another example of a deflecting member suitable for the projection exposure apparatus shown in FIG.

6 is a view showing another example of a deflecting member suitable for the projection exposure apparatus shown in FIG.

[Explanation of symbols]

 1 Light Source 10 Fly's Eye Lens 11 Deflection Member 11A Parallel Plate 15 Photoelectric Detector 16 Condenser Lens Group 17 Reticle 18 Reticle Mark 19 Projection Optical System 20 Reference Member 21 Wafer 22 Wafer Stage 26 Optical Fiber 29 Main Control System 30 Alignment Sensor FM Reference Mark

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location 7352-4M H01L 21/30 311 S

Claims (4)

[Claims] 1. An illumination optical system for shaping illumination light from a light source into a substantially uniform intensity distribution and irradiating it on a mask, and a photosensitive substrate on which an image of a pattern formed on the mask is transferred can be held and moved. A substrate stage, and a reference member provided on the substrate stage and having a reference pattern of a predetermined shape,
A projection exposure apparatus comprising: an irradiation unit that irradiates the reference member with the illumination light; and a detection unit that detects light generated from the reference pattern that passes through the mask, the optical axis of the illumination optical system being A light flux deflecting member disposed in a substantially vertical plane for deflecting light generated from the reference pattern to the outside of the optical path of the illumination optical system, the light flux deflecting member transferring the mask pattern to the photosensitive substrate. A projection exposure apparatus, which is sometimes removed from the optical path of the illumination optical system. 2. An illuminating optical system that illuminates an illumination light from a light source into a substantially uniform intensity distribution and irradiates the mask, and a photosensitive substrate to which an image of a pattern formed on the mask is transferred can be held and moved. A substrate stage, and a reference member provided on the substrate stage and having a reference pattern of a predetermined shape,
A projection exposure apparatus comprising: an irradiation unit that irradiates the reference member with the illumination light; and a detection unit that detects light generated from the reference pattern that passes through the mask, the optical axis of the illumination optical system being A substrate which is arranged in a substantially vertical plane and which is substantially transparent to the illumination light; a light beam deflection which is arranged in the vicinity of the transparent substrate and makes the light generated from the reference pattern incident on the transparent substrate at an angle. The light flux deflecting member is removed from the optical path of the illumination optical system when the mask pattern is transferred to the photosensitive substrate, and the detecting means propagates through the inside of the substrate to provide the illumination. A projection exposure apparatus, which detects light from the reference pattern guided to the outside of the optical path of an optical system. 3. The projection exposure apparatus according to claim 2, wherein the light beam deflecting member is integrally provided on a surface of the transparent substrate on the mask side. 4. The light flux deflecting member is arranged on an optical Fourier transform plane for the pattern of the mask in the illumination optical system, or on a plane in the vicinity thereof, according to claim 2 or 3. The projection exposure apparatus described.