JPH0513300A - Projecting exposure device - Google Patents

Abstract

PURPOSE:To make intensity distribution of a light to be irradiated on a surface of a mask uniform by providing a ring bandlike aperture in a rear stage of a fly eye lens. CONSTITUTION:A rotating mechanism having a rotary driver 5 and a rotary shaft 5a, is provided, a fly eye lens 3 is rotated at the shaft 5a as a center, and a timing superposition of light source lights on a mask 8 is obtained.

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. 5 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. 6 is a high-resolution imaging optical system of FIG. It is a block diagram of the projection exposure apparatus using. In FIGS. 5 and 6, 1 is a lamp house for light source light, 2 is a mirror that reflects the light source light of the lamp house 1, 3 is a fly-eye lens composed of a plurality of single lenses 3a assembled together, 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. 7). 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]

The conventional projection exposure apparatus is constructed as described above, and because it uses a ring-shaped aperture, it has a good resolution and a deep depth of focus, but on the other hand, it is a fly-eye lens in the preceding stage. Only part of the light transmitted through the individual lens areas of the light passes through the zonal aperture. Therefore, only a part of the light that has passed through each lens area of the fly-eye lens reaches the mask surface, effectively reducing the number of divisions of the fly-eye lens and reducing the number of light superpositions. There is a problem that the distribution of the light intensity for irradiating the mask surface becomes non-uniform.

The present invention has been made to solve the above problems, and a projection exposure apparatus capable of providing substantially uniform illumination without uneven distribution of the intensity of light illuminating the mask surface. Aim to get.

[0007]

In a projection exposure apparatus according to the present invention, a fly-eye lens is provided, while the optical axis cross section of the fly-eye lens is kept substantially parallel to the surface of the aperture.
It is provided with a moving means for spatially moving.

[0008]

In the present invention, the fly-eye lens is designed to move spatially while its optical axis cross section remains substantially parallel to the plane of the aperture. That is, a temporal averaging action occurs, which is effectively equivalent to an increase in the number of divided fly-eye lenses, and uniform illumination can be performed.

[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. 6 denote the same or corresponding parts, and 5 is a rotary drive unit of the fly-eye lens 3, and the fly-eye lens 3 is rotated about a rotary shaft 5 a of the rotary drive unit 5. Is configured.

Next, the operation will be described. The light emitted from the lamp house 1 reaches a fly-eye lens 3 having a rotation mechanism composed of a rotation drive unit 5 and a rotation shaft 5a via a mirror 2 and is divided into regions of individual lenses 3a constituting the fly-eye lens 3. It Then, at a certain time t ₁ , each lens 3a
The light that has passed through passes through the opening 4 a of the annular aperture 4 and illuminates the entire exposure area of the mask 8 via the mirror 6 and the condenser lens 7. The fly-eye lens 3 seen from the mask 8 at this time is shown in FIG. The light source light emitted from the lamp house 1 is divided into, for example, the shape shown in FIG. 2, that is, a plurality of shapes having boundaries in the horizontal and vertical directions, and then the mask 8
Will be overlaid at.

Then, at time t ₂ which is later than time t ₁ by Δt, individual lenses 3a constituting the fly-eye lens 3 are formed.
Similarly, the light transmitted through irradiates the entire surface of the exposure area of the mask 8 through the opening 4a of the band-shaped aperture 4, the mirror 6 and the condenser lens 7, but the fly-eye lens 3 corresponds to the time Δt. It rotates about the rotation axis 5a by an angle. Therefore, the fly-eye lens 3 seen from the mask 8 at time t ₂ has a shape with the oblique direction as a boundary, as shown in FIG. That is, the way the light from the light source is divided as viewed from the mask 8 is different.

Therefore, the wafer 10 is rotated by using the rotary drive unit 5.
Irradiation time, that is, the irradiation time to the mask 8 is the time Δ
If set to be longer than t, the irradiation light intensity on the mask 8 is temporally superposed with differently divided light source light, so that the intensity distribution of the light source light is averaged to obtain a substantially uniform distribution. become. Then, the light having the uniform light intensity reaches the wafer 10 via the projection lens 9, and the pattern is printed on the surface of the wafer 10.

As described above, according to this embodiment, since the rotation mechanism including the rotation drive unit 5 and the rotation shaft 5a is provided to rotate the fly-eye lens 3 about the rotation shaft 5a, the mask at each time is set. The light passing through the individual lenses 3a of the fly-eye lens 3 is superposed on the surface of the mask 8, and the uneven illuminance on the mask 8 disappears, and the light intensity distribution on the wafer surface becomes uniform.

In the above embodiment, the fly-eye lens 3 is used.
The configuration described above is configured to rotate about an axis substantially parallel to the optical axis 11, but it may be configured to reciprocate in a cross section perpendicular to the optical axis 11 as shown in FIG. That is, in FIG. 4, 3'is a fly-eye lens whose position is changed with respect to the optical axis 11 by reciprocating motion, 3a 'is its individual lens, 3a'.
0 indicates the direction of the reciprocating motion. By doing so, the irradiation light intensity on the mask 8 is a temporal superposition of light from the light sources that are differently divided, so that the same effect as that of the above-described embodiment can be obtained.

In FIG. 4, the direction 30 of the reciprocating motion is the vertical direction on the paper surface, but it may be the direction perpendicular to the paper surface or the oblique direction.

[0016]

As described above, according to the projection exposure apparatus of the present invention, since the fly-eye lens is configured to move with time, the number of spatial divisions of the fly-eye lens due to the influence of the ring-shaped aperture light-shielding portion is reduced. The decrease can be compensated with respect to time, and there is an effect that light with a uniform intensity distribution can be obtained on the mask surface.

[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 how the fly-eye lens divides the light source light at a certain time in the projection exposure apparatus according to the embodiment of the present invention.

FIG. 3 is a diagram showing how the fly-eye lens divides the light source light at another time in the projection exposure apparatus according to the embodiment of the present invention.

FIG. 4 is a diagram showing a configuration of a projection exposure apparatus according to another embodiment of the present invention.

FIG. 5 is a diagram showing a high resolution optical system of a conventional projection exposure apparatus.

FIG. 6 is a diagram showing a configuration of a conventional projection exposure apparatus.

FIG. 7 is a plan view of an annular aperture.

[Explanation of symbols]

1 Light source lamp house 2 mirror 3 fly eye lens 4 ring-shaped aperture 5 Fly-eye lens driver 6 mirror 7 Condensing lens 8 masks 9 Projection imaging lens 10 wafers 11 optical axis

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] January 21, 1992

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

   ─────────────────────────────────────────────────── ─── 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 fly-eye lens that receives light emitted from the light source and has a plurality of unit lenses arranged in a matrix, and an annular light-transmitting region, and passes through the fly-eye lens. An aperture that blocks a part of the light, a condenser lens system that condenses the light that has passed through the aperture, a mask that has the circuit pattern formed by the light that has passed through the condenser lens, and a mask that passes through the mask. A projection lens system for converging the formed light on the wafer surface and the fly-eye lens, while keeping the optical axis cross section of the fly-eye lens substantially parallel to the surface of the aperture,
A projection exposure apparatus comprising: a moving unit that moves spatially. 2. The projection exposure apparatus according to claim 1, wherein the moving means rotates the fly-eye lens about an axis substantially parallel to an optical axis of the fly-eye lens. . 3. The projection exposure apparatus according to claim 1, wherein the moving means moves the fly-eye lens back and forth in a plane perpendicular to the optical axis of the fly-eye lens.