JPH01101628A - Reducing stepper - Google Patents

Abstract

PURPOSE:To assure successive exposure of a semiconductor device pattern of a size larger than an effective exposure region possessed by a reducing projection optical system by continuously controlling the operation of selecting a plurality of optical paths of a focusing optical system and the operation of moving a stage with high accuracy. CONSTITUTION:The title capacitor device includes a reducing projection optical system composed of two sets of exposure illumination optical systems 1-4 and optical focusing systems 5-7, and an optical path changeover optical system provided in the reducing projection optical system and composed of a plurality of relay lenses 9, a plurality of lenses 10, a split field mirror 11, and a roof prism 12 for parallely moving a transmission optical axis with respect to an incident optical axis in response to an incident angle. An exposure illuminating light illuminates two reticles 8 mounted between the focusing optical system and the optical path changeover optical system in a desired direction. Hereby, since a transmitted optical beam is introduced so as to advance along the center of the optical axis of the reducing projection optical system, the optical path changeover optical system can select the optical path of a desired focusing optical system to permit a wafer 15 mounted on a high precision movable stage 14 to be exposed to a desired pattern in the two reticles to be exposed in succession to the light at a desired position on a wafer 15 mounted on a high precision movable stage 14.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention applies a photolithography process in a semiconductor manufacturing process to a semiconductor substrate (hereinafter referred to as a wafer) whose surface is coated with a photosensitive material (hereinafter referred to as a photoresist). This invention relates to an apparatus for performing reduction projection exposure processing on a pattern of a quartz mask (hereinafter referred to as a reticle) having a pattern of .

[Prior Art] As shown in FIG. 3, the exposure optical system of a conventional reduction projection exposure apparatus includes an exposure illumination lamp 1, a condensing mirror 2, a plurality of integrator lenses 3, and a shutter 4. It consists of an optical system, a condensing optical system consisting of a plurality of relay lenses 5, a light shielding plate 6 for setting the exposure illumination range, a condenser lens 7, and a reduction projection optical system consisting of a reduction projection lens 13. ing.

In the wafer exposure process, a uniform light beam irradiated from the exposure illumination optical system is directed only to the exposure illumination range set by the condensing optical system to the reticle 8 mounted between the condensing optical system and the reduction projection optical system. The projected image is reduced to 115, 1/10, etc. and projected onto the surface of the wafer 15 mounted on a high-precision moving stage 14 by a reduction projection optical system, and subjected to exposure processing.

The exposure process described above and the movement of the stage on which the wafer is mounted are repeated to expose the entire surface of the wafer.

[Problems to be Solved by the Invention] The conventional reduction projection exposure apparatus described above has a uniaxial optical path from the condensing optical system to the reduction projection optical system. Exposure processing of element patterns is basically impossible.

If you want to do this forcibly, you would have to divide the semiconductor element pattern into several parts, create a reticle for each part, replace the reticle mounted on the device every time you expose that part, and then perform the exposure process again. It's not impossible.

However, it is necessary to replace each partial reticle by the number of divisions of the semiconductor element pattern for - wafers, so when processing several wafers, the reticle must be replaced many times, which greatly reduces processing efficiency. It becomes bad.

Furthermore, the alignment error for the device when changing each reticle,
This is practically impossible because many error factors occur, such as errors in alignment of each reticle to the wafer during each exposure process.

Furthermore, in recent years, as the density and performance of semiconductor devices has increased, there has been a growing demand for the production of large-sized semiconductor devices with fine patterns.

However, high resolution for resolving fine patterns and expanding the effective exposure range are contradictory when designing and manufacturing a reduction projection lens, and it is currently difficult to realize a reduction projection lens that achieves both. be.

SUMMARY OF THE INVENTION An object of the present invention is to provide a reduction projection exposure apparatus that solves the above-mentioned problems.

[Means for Solving the Problems] The present invention provides a reduction projection optical system for an apparatus for reducing projection exposure processing of a desired mask pattern on the surface of a semiconductor substrate mounted on a high-precision moving stage in a semiconductor manufacturing process. Exposure processing is performed by using multiple condensing optical systems that irradiate exposure illumination onto a reticle that has previously been provided with a desired mask pattern, and by switching the optical path from the condensing optical systems to the reduction projection optical system in synchronization with the movement of the moving stage. This is a reduction projection exposure apparatus characterized by having a mechanism. .

[Example] Hereinafter, the present invention will be explained with reference to the drawings.

(Embodiment 1) FIG. 1 shows a first embodiment of the present invention, and is a schematic diagram of one equipped with two condensing optical systems.

The reduction projection exposure apparatus according to the first embodiment of the present invention includes an exposure illumination optical system composed of an exposure illumination lamp 1, a condensing mirror 2, a plurality of integrator lenses 3, and a shutter 4, and a plurality of relay lenses 5 and an exposure illumination optical system. Two sets of condensing optical systems each consisting of a light shielding plate 6 and a condenser lens 7 are used to set the illumination range, and a plurality of relay lenses 9 are installed between the reduction projection optical system consisting of a reduction projection lens 13. The optical path switching optical system is composed of a mirror 10, a split field mirror 11, and a roof prism 12 that moves the transmitted optical axis parallel to the incident optical axis according to the incident angle.

The optical path switching optical system is used to irradiate the exposure illumination light to the desired direction of the two reticles 8 mounted between the condensing optical system and the optical path switching optical system, and to introduce the transmitted light beam to the center of the optical axis of the reduction projection optical system. It is possible to select a desired optical path of the condensing optical system depending on the system and continuously expose a desired pattern on two reticles at a desired position on the wafer 15 mounted on the high-precision moving stage 14. It is said that

(Embodiment 2) FIG. 2 shows a second embodiment of the present invention. In this embodiment, a part of the exposure illumination system consisting of an exposure illumination lamp 1 and a condensing mirror 2 is shared by two sets of condensing optical systems, unlike the embodiment shown in FIG. The optical system is divided into two condensing optical systems using a mirror 10 and a split field mirror 11.

As described above, in both embodiments, semiconductor element patterns exceeding the effective exposure range of the reduction projection optical system can be formed on the wafer by controlling the operation of selecting the optical paths of a plurality of condensing optical systems in conjunction with the operation of the high-precision moving stage. It allows continuous exposure processing.

[Effects of the Invention] As explained above, according to the present invention, it is possible to perform continuous exposure processing of a semiconductor element pattern having a size larger than the effective exposure range of the reduction projection optical system, and to manufacture a large-sized semiconductor element having a fine pattern. This has the effect of being able to respond to

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a first embodiment of the invention, FIG. 2 is a schematic diagram showing a second embodiment of the invention, and FIG. 3 is a schematic diagram showing a conventional reduction projection exposure apparatus. . 1...Exposure illumination lamp 2...Collecting mirror 3...
・Integrator lens 4...Shutter 5...Relay lens 6・
・・Light shielding plate 7・・Condenser lens 8・
...Reticle 9...Relay lens 10...
・Mirror 11...Split field mirror 12
... Roof prism 13 ... Reduction projection lens 1
4...Movement stage 15...Wafer Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] (1) In a device that performs reduction projection exposure processing of a desired mask pattern on the surface of a semiconductor substrate mounted on a high-precision moving stage in a semiconductor manufacturing process, a reticle equipped with a desired mask pattern is placed before the reduction projection optical system. A reduction device characterized by having a plurality of condensing optical systems that irradiate exposure illumination to a moving stage, and a mechanism that performs exposure processing by switching the optical path from the condensing optical system to the reduction projection optical system in synchronization with the movement of the moving stage. Projection exposure equipment.