JPH0513301A - Projection aligner - Google Patents

Abstract

PURPOSE:To enhance the utilization efficiency of rays from a light source in a stepper provide with loop aperture having an opening arranged behind a fly's-eye lens. CONSTITUTION:A photointensity distributiona shaping optical system 5 is arranged between a mirror 2 and a fly's-eye lens 3 to shape the light source rays from a lamp house 1. Thus, the light source rays are incident upon the fly's-eye lens 3 as the rays prepared to be adaptable to the opening 4a of a loop aperture 4 rays.

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 in an LSI manufacturing process.

[0002]

2. Description of the Related Art FIG. 6 is a block diagram of a conventional high-resolution imaging optical system disclosed in, for example, Japanese Patent Laid-Open No. 58-7123, and FIG. 7 is a high-resolution imaging optical system of FIG. It is a block diagram of the projection exposure apparatus using. In FIGS. 6 and 7, 1 is a lamp house for light source light, 2 is a mirror for reflecting the light source light of the lamp house 1, 3 is a fly-eye lens formed by collecting a plurality of single lenses 3a, and 4 is a fly-eye lens. A ring-shaped aperture that blocks part of the light that has passed through the lens 3, 6 a mirror that reflects the light that has passed through the ring-shaped aperture 4, 7 is a condenser lens, 8 is a patterned mask, 9 is a projection imaging lens,
A wafer 10 is placed on the image plane.

Next, the operation will be described. The light emitted from the lamp house 1 reaches the fly-eye lens 3 via the mirror 2 and is divided into the regions of the individual lenses 3 a forming the fly-eye lens 3. The light passing through each lens 3a reaches the ring-shaped aperture 4 (see FIG. 8). Here, a part of the light is blocked by the light blocking portion 4b of the ring-shaped aperture 4, but a part of the light passes through the opening 4a and passes through the mirror 6 and the condenser lens 7 so that the entire exposure area of the mask 8 is exposed. Irradiate. In this way, the light beams that have passed through the individual lenses 3a of the fly-eye lens 3 are superposed and irradiated on the mask 8 surface.

At this time, the light irradiating the mask 8 is the light passing through the ring-shaped aperture 4 whose central portion is shielded (light whose opening is the secondary light source of the ring-shaped aperture 4).
The mask 8 will be irradiated obliquely. In this way, the light that obliquely irradiates the mask 8 passes through the projection lens 9 and reaches the wafer 10, which prints a pattern on the surface of the wafer 10. As a result, the resolution is good and exposure with a deep depth of focus is possible.

[0005]

Since the conventional projection exposure apparatus is constructed as described above, only a part of the light from the lamp house passes through the ring-shaped aperture, and the utilization efficiency of the light from the light source is poor. Therefore, in order to secure the exposure amount on the wafer, it is necessary to increase the light amount of the lamp or lengthen the exposure time of the wafer. However, increasing the light quantity of the lamp causes a large thermal influence on the surroundings, which deteriorates the accuracy of the exposure pattern and shortens the life of the lamp. Further, if the exposure time of the wafer is lengthened, there is a problem that throughput is lowered.

The present invention has been made to solve the above-mentioned problems, and an object thereof is to obtain a projection exposure apparatus which makes efficient use of light from a light source.

[0007]

SUMMARY OF THE INVENTION A projection exposure apparatus according to the present invention is a light intensity distribution shaping optical for shaping a source light into a shape adapted to an opening of a ring-shaped aperture between optical paths of a light source and the ring-shaped aperture. It is equipped with a system.

[0008]

In the present invention, since the light intensity distribution shaping optical system shapes the light intensity distribution of the light source light into a shape suitable for the opening of the annular aperture, most of the light emitted from the light source is formed. Will pass through the ring-shaped aperture.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A projection exposure apparatus according to an embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, the same reference numerals as those in FIG. 7 denote the same or corresponding portions, 5 is a light intensity distribution shaping optical system provided between the mirror 2 and the fly-eye lens 3, and FIG. 2 shows its detailed configuration. Reference numeral 501 denotes light before entering the light intensity distribution shaping optical system 5, and 502 denotes light after passing through the light intensity distribution shaping optical system 5. The convex lens 51, the concave lens 52, and the concave mirror 53 having a small hole 53a at the center. , Convex mirror 54.

Next, the operation will be described. The light from the lamp house 1 passes through the mirror 2 and the light intensity distribution shaping optical system 5
Reach the convex lens 51. At this time, the light 501 illuminates almost the entire surface of the convex lens 51. The light 501 is a combination of a convex lens 51 and a concave lens 52 having an appropriate focal length, and a small hole 53 formed in the center of the concave mirror 53.
It is focused into parallel light having a size equal to the radius of a, and the small hole 53
led to a. Further, the light passing through the small hole 53a is reflected by the convex mirror 54 while changing its direction away from the optical axis, and returns to the concave mirror 53. The light returning to the concave mirror 53 is reflected again toward the convex mirror 54 in parallel with the optical axis.
Thus, the light travels back and forth a plurality of times from the center to the periphery between the concave mirror 53 and the convex mirror 54, and finally becomes the annular parallel light 502 from the periphery of the convex mirror 54 and is applied to the fly-eye lens 3. It

At this time, since the ring-shaped parallel light 502 conforms to the shape of the opening 4a of the ring-shaped aperture 4, the light passing through the fly-eye lens 3 is not blocked by the light-shielding part of the ring-shaped aperture 4. Passing through the opening 4a,
The mask 8 is irradiated through the mirror 6 and the condenser lens 7 in the next stage, and finally passed through the projection imaging lens 9 to finally obtain the wafer 10.
To reach.

As described above, according to this embodiment, the light intensity distribution shaping optical system 5 is provided between the mirror 2 and the flyer lens 3, the light source light from the lamp house 1 is shaped, and the ring-shaped aperture 4 is previously formed. Since the light is made incident on the fly-eye lens 3 so as to be compatible with the opening 4a, the light is sent to the optical system of the next stage without being largely damaged by the ring-shaped aperture 4, and a sufficient exposure amount on the wafer 10 is obtained. Can be secured.

In the above embodiment, a set of a convex lens and a concave lens is used for focusing light of the light intensity distribution shaping optical system 5.
As shown in FIG. 3, a set of convex lenses may be used, and similarly, parallel light having the same size as the small holes 53a of the concave mirror 53 can be obtained.

In the above embodiment, the light incident on the small hole 53a of the concave mirror 53 is parallel light, but it may be focused light as shown in FIG. 4. At this time, the light intensity distribution shaping optical system 5 is used. Convex lens 51c, concave mirror 53c, convex mirror 54c
It consists of 3 sheets.

FIG. 5 shows still another embodiment of the light intensity distribution shaping optical system 5, in which the light 501 becomes an annular light by the conical lens 55 and becomes parallel light 502 by the lens 56 and becomes a light intensity distribution shaping optical system. It is emitted from 5.

[0016]

As described above, according to the projection exposure apparatus of the present invention, the light intensity distribution shaping optical system is provided between the optical paths of the light source and the ring-shaped aperture, and the source light is formed into the opening shape of the ring-shaped aperture. After shaping into a suitable shape, the ring-shaped aperture is irradiated, so the light utilization efficiency is improved without impairing the amount of light in the ring-shaped aperture, the throughput of pattern printing is improved, and the accuracy is high. Is obtained.

[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 configuration diagram of a light intensity distribution shaping optical system of the projection exposure apparatus according to the embodiment of the present invention.

FIG. 3 is a configuration diagram of a light intensity distribution shaping optical system according to a second embodiment of the present invention.

FIG. 4 is a configuration diagram of a light intensity distribution shaping optical system according to a third embodiment of the present invention.

FIG. 5 is a configuration diagram of a light intensity distribution shaping optical system according to a fourth embodiment of the present invention.

FIG. 6 is a block diagram of a conventional high resolution optical system.

FIG. 7 is a diagram showing a configuration of a conventional projection exposure apparatus.

FIG. 8 is a plan view of a ring-shaped aperture.

[Explanation of symbols]

1 lamp house 2 mirror 3 fly eye lens 4 ring-shaped aperture 5 Light intensity distribution shaping optical system 6 mirror 7 Condensing lens 8 masks 9 Projection imaging lens 10 wafers 51 convex lens 52 concave lens 53 concave mirror 54 Convex mirror 501 Light intensity distribution shaping light incident on the optical system 502 Light emitted from the light intensity distribution shaping optical system

Continued front page    (72) Inventor Nobuyuki Motomoto             3-1-1 Tsukaguchihonmachi, Amagasaki City, Hyogo Prefecture             Ryoden Co., Ltd., Production Technology Laboratory (72) Inventor Toshinori Yagi             3-1-1 Tsukaguchihonmachi, Amagasaki City, Hyogo Prefecture             Ryoden Co., Ltd., Production Technology Laboratory (72) Inventor Kazuya Kamon             4-1-1 Mizuhara, Itami City, Hyogo Prefecture Mitsubishi Electric             LSI Research Institute Co., Ltd. (72) Inventor Masaaki Tanaka             3-1-1 Tsukaguchihonmachi, Amagasaki City, Hyogo Prefecture             Ryoden Co., Ltd., Production Technology Laboratory

Claims (3)

[Claims] 1. A light source, a condenser lens system for irradiating a light source light emitted from the light source onto a mask having a circuit pattern formed thereon, and a projection lens system for condensing light passing through the mask onto a wafer surface. And an aperture having a ring-shaped light transmitting region arranged between the light source and the condenser lens system, and a shape adapted to match the light source light to the light transmitting region of the aperture between the light paths of the light source and the aperture. And a light intensity distribution shaping optical system for shaping the projection exposure apparatus. 2. The projection exposure apparatus according to claim 1, wherein the light intensity distribution shaping optical system comprises a reflection type optical element including a concave mirror and a convex mirror. 3. The projection exposure apparatus according to claim 1, wherein the light intensity distribution shaping optical system comprises a transmission type conical lens.