JPH0548930B2 - - Google Patents

Description

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

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

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. irradiated,
The projected image is reduced to 1/5, 1/10, etc. and projected onto the surface of a 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 for each wafer by the number of divisions of the semiconductor element pattern, so when processing multiple wafers, the reticle must be replaced many times, resulting in extremely low processing efficiency. Become something.

Furthermore, many error factors occur, such as alignment error with the apparatus when each reticle is replaced and alignment error of each reticle with the wafer during each exposure process, making it practically impossible.

Furthermore, in recent years, as the density and performance of semiconductor devices have 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 in designing and manufacturing reduction projection lenses, and it is currently difficult to realize reduction projection lenses that achieve 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] In order to achieve the above object, a reduction projection exposure apparatus according to the present invention includes a set of an exposure illumination optical system and a condensing optical system, and an optical path switching optical system. A reduction projection exposure apparatus that moves a substrate within a plane using a stage and performs continuous exposure processing on the surface of the semiconductor substrate of a pattern with dimensions larger than the effective exposure range of a reduction projection optical system, the apparatus comprising: a set of exposure illuminations; The optical system and the condensing optical system are provided with at least the same number of sets as the number of exposure areas obtained by dividing the pattern, and the optical axes are arranged in parallel, and each set of the exposure illumination optical system and the condensing optical system is arranged in such a manner that the exposure illumination optical system and the condensing optical system of each group The optical path switching optical system selects one set from among multiple sets of exposure illumination optical systems and focusing optical systems whose optical axes are parallel, and changes the optical path. This is to switch to a reduction projection optical system.

[Example] The present invention will be described below with reference to the drawings.

(Example 1) Figure 1 shows the first example of the present invention.
FIG. 2 is a schematic diagram of a device including 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. There are two sets of condensing optical systems each consisting of a light shielding plate 6 and a condenser lens 7 for setting the illumination range, and a plurality of relay lenses 9 and a plurality of The optical path switching optical system is constituted by 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. Select the desired optical path of the focusing optical system depending on the system and move the high-precision moving stage 1
It is possible to successively expose a desired pattern of the two reticles to a desired position on the wafer 15 mounted on the reticle.

(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. A mirror 10 and a split field mirror 11 are used to divide the condensing optical system into two sets.

As described above, in both embodiments, semiconductor device 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 path 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 present invention;
FIG. 2 is a schematic diagram showing a second embodiment of the present 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, 14...Movement stage, 15...
...Wafer.

Claims (1)

[Scope of Claims] 1. A system comprising a set of an exposure illumination optical system and a focusing optical system, and an optical path switching optical system, in which a semiconductor substrate is moved within a plane by a stage, and a semiconductor substrate is placed on the surface of the semiconductor substrate.
It is a reduction projection exposure apparatus that performs continuous exposure processing of a pattern with dimensions larger than the effective exposure range of the reduction projection optical system, and the exposure illumination optical system and the condensing optical system that form a set are configured to cover the exposure area into which the pattern is divided. At least the same number of sets are arranged with their optical axes parallel to each other, and each set of exposure illumination optical system and condensing optical system has a reticle that individually exposes each area of the divided pattern, Reduction projection exposure characterized in that the optical path switching optical system selects one set from among a plurality of sets of exposure illumination optical systems and condensing optical systems whose optical axes are parallel, and switches the optical path to a reduction projection optical system. Device.