JPH02133914A - Arc illumination apparatus - Google Patents

Abstract

PURPOSE:To reduce an irregularity in an intensity of illumination to a minimum by a method wherein an optical fiber bundle is composed of a plurality of partial optical fiber bundles, radiant ends of the partial optical fiber bundles arranged in an arc row shape are laminated at a radiant end and incident ends of the partial optical fiber bundled are bundles at an incident end. CONSTITUTION:Optical fiber strands 21 are arranged in one row in a length direction of an arc at a radiant end 22; they are bundled as one bundle at an incident end 23; a partial optical fiber bundle A is formed; partial optical fiber bundles A to T are laminated at the radiant end 22; an arc-slit-shaped radiant end 24 is formed as a whole. They are bundled at the side of the incident end 23; a disk-shaped incident end 25 is formed as a whole. A beam, from a point light-source lamp, which is incident on the disk-shaped incident end 25 at this optical fiber bundle 26 is incident on the partial optical fiber bundles A to T; it is radiated, from the arc-slit-shaped radiant end 24, as a beam bundle which has been stretched in one row in the length direction of the arc at the individual partial optical fiber bundles A to T; a laminated arc slit illumination is obtained as a whole.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an arc illumination device in an exposure apparatus used for forming semiconductors, electronic circuits, and the like.

2. Description of the Related Art In recent years, batch exposure of patterns in semiconductor manufacturing has been carried out using a reflection type projection exposure apparatus, and its illumination optical system requires arcuate slit illumination.

Recently, the use of optical fibers has been proposed to efficiently realize circular arc slit illumination (for example,
(See Publication No. 2-2618). Fig. 5 shows the principle of its construction, in which 1 is an ultra-high pressure mercury lamp, 2 is an ellipsoidal reflector, and 3 is a disc-shaped entrance end 4 and an arc-shaped exit end 6.
A quartz optical fiber bundle 6 is a relay lens that projects a portion of the arcuate slit-shaped exit end 5 onto a mask 7 as a projection image 8. In order to eliminate uneven illumination, the quartz fiber bundle 3 has its strands arranged randomly at the input end and the output end.

Its operation is such that the arc light from the ultra-high pressure mercury lamp 1 placed at the first focus of the ellipsoidal reflector 2 is reflected as light rays 9 and 10.
Optical fiber bundle 3 placed at the second focal point of the ellipsoidal reflector 2
The light enters through the disc-shaped entrance end 4, passes through the optical fiber, and exits through the arc-shaped exit end 6. A projected image 8 of the light emitted from the arcuate exit end 5 is formed on the stripe surface 7 by the relay lens 6. To illuminate the entire mask, point mask 7 to arrow 1.
This is done by scanning in one direction. Further, the projected image 8 does not faithfully reproduce the arc-shaped exit end 5 due to the characteristics of the relay lens 6, and it is possible to reduce unevenness in illuminance by using blur.

Problems to be Solved by the Invention However, depending on the configuration described above, it is actually difficult to arrange the optical fiber strands completely randomly at the input end 4 and exit end 5 of the optical fiber 3; The unevenness in the amount of light caused the unevenness in the amount of light on the exit end surface. Furthermore, projecting the image of the arcuate exit end 6 onto the mask 7 inevitably leads to a decrease in the amount of illumination light.

Means for Solving the Problems In order to solve the above problems, the arc illumination device of the present invention has an optical fiber bundle composed of a plurality of partial optical fiber bundles, the output ends of which are arranged in rows in the length direction of the arc. The output ends of the optical fiber bundles are laminated, and the input ends of the optical fiber bundles are constructed by further bundling the bundled input ends of the partial optical fiber bundles.

Effect of the Invention The present invention has the above-described configuration, so that even if there is unevenness in the amount of light on the input end of the optical fiber bundle, the unevenness in the amount of light is minimal in the length direction of the arc at the exit end, thereby eliminating uneven exposure. be able to.

Embodiment Hereinafter, an arc illumination device according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of a partial optical fiber bundle of an arc illumination device in a first embodiment of the present invention. In Figure 1,
21 is an optical fiber strand, and A is a partial optical fiber bundle which is arranged in a line in the length direction of the arc at the exit end 22 and bundled into a bundle at the input end 23. FIG. 2 is a schematic diagram showing how the partial optical fiber bundles AT are stacked at the exit end 22. The whole forms an arcuate slit-shaped injection end 24. FIG. 3 is a schematic diagram showing how the partial optical fiber bundles A and T are bundled on the input end 23 side. The whole forms a disc-shaped entrance end 26.

The partial optical fiber bundles A and T at the exit end 24 in FIG. 2 are connected to the partial optical fiber bundles A-T at the input end 26 in FIG.

The operation of the arc illumination device having the optical fiber bundle 26 configured as described above is such that the light from the point light source lamp that enters the disc-shaped entrance end 26 in FIG.
from the arcuate slit-shaped injection end 26 shown in FIG.
Each of the partial optical fiber bundles A-, . Even if there is unevenness in the amount of light at the input end 26 in FIG. 3, at the exit end 24 in FIG. In the direction of the arc exposure scanning direction arrow 27, each layer A
, T appears as a difference in light amount. However, during actual exposure, the uneven illuminance distribution in the scanning direction does not pose a problem because it is added up during exposure scanning and becomes effective as the total amount of exposure light.

FIG. 4 shows the input end of the optical fiber bundle 26 in a second embodiment of the present invention, and the partial optical fiber bundles A-, T
The annular entrance end 28 is formed by bundling the wafers in a concentric ring shape, and the shape of the other parts is the same as that in the first embodiment. This is effective for allowing a dark illumination light beam to enter the center using an ellipsoidal reflector as shown in FIG.

Effects of the Invention As described above, the present invention has an exit end formed by laminating arc-shaped exit ends of a plurality of partial optical fiber bundles, and an input end formed by further bundling a plurality of partial optical fiber bundles. Furthermore, it is possible to provide an arcuate illumination device for a reflective projection exposure device with minimal illuminance unevenness.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a partial optical fiber bundle in the first embodiment of the present invention, FIG. 2 is a configuration diagram showing the structure of the exit end of the optical fiber bundle of the illumination device of the present invention, and FIG. FIG. 4 is a configuration diagram showing the structure of the input end of the optical fiber bundle in the second embodiment of the present invention.
The figure is a configuration diagram of a conventional arcuate slit-shaped illumination device. 21... Optical fiber strand, 22... Output end of partial optical fiber bundle, 23... Input end of partial optical fiber bundle, 24... Arc slit-shaped exit end,
25... Disc-shaped input end, 26... Optical fiber bundle, 28 Annular input end, A-T... Partial optical fiber second diagram bundle. Name of agent: Patent attorney Shigetaka Awano and 1 other person 3 Figure 2y--One yen η TOKINJIN J FUNE DING Figure 2F-East Line A-Ichisako Chitato to Fa M-Song, 24-1/Fl No. Rimatari... To Tsuede Fr ÷ 26 - First Pu F / No 1 - Bunch 4 ~ D - # All Sushi Fuda Bar East

Claims (2)

[Claims] (1) having an optical fiber bundle comprising a light input end formed by bundled optical fibers and a light exit end shaped into an arc;
In an arc illumination device that creates arcuate slit-shaped illumination from a point light source, the optical fiber bundle is composed of a plurality of partial optical fiber bundles, and the output end is the output end of the partial optical fiber bundles arranged in a row in the length direction of the arc. An arc lighting device characterized in that the input end of the optical fiber bundle is configured by further bundling the bundled input ends of the partial optical fiber bundles. (2) The arc illumination device according to claim 1, wherein the input end of the optical fiber bundle is formed by bundling partial optical fiber bundles into an annular bundle.