JPS61258426A - Reduction projection exposure device - Google Patents

Abstract

PURPOSE:To enable to perform the foreign matter detection on the surface of a reticle in parallel with the contracted projection exposure by means of providing the titled device with multiple sets of lighting optical systems and foreign matter detective means. CONSTITUTION:Firstly a reticle 3b whereon a pattern is formed is set on a scan-holding board 4b to detect any foreign matters on the surface of reticle 3b by means of a foreign matter detective means 11b. In order words, the surface of reticle 3b is irradiated with laser beams 8a from a laser emitting part 8 through a scan-reflecting mirror 9 to be scanned e.g. in X axial direction while the scan-holding board 4b is constituted to be movable stepwise in Y axial direction so that the laser beams 8a may successively scan the overall surface of reticle 3b. At this time, any laser beams 8a scattered on the surface of reticle 3b are detected by a scattered beams detector 10 to automatically check the existence of any foreign matters on the surface of reticle 3b. Through these procedures, the foreign-matter detection and the projection exposure on the surface of reticle 3b can be performed in parallel with each other since the titled device using X and Y stage 7 in common is provided with two sets of foreign matter detective means 11a, 11b and lighting optical systems 1a, 1b.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a reduction projection apparatus used for manufacturing semiconductor devices.

[Conventional technology]

Conventionally, in the manufacturing process of semiconductor devices, a method has been used in which a pattern of a reticle is reduced and projected onto a semiconductor phenol (hereinafter simply referred to as urchin I), and sequential step exposure is performed. In this case, if foreign matter such as dust or particles is present on the surface of the reticle, the pattern of these foreign matter will be repeatedly transferred to all chips on the wafer, resulting in the entire wafer becoming defective and becoming a major factor in reducing the productivity of semiconductor devices. was.

In particular, with the demand for higher integration and higher density of semiconductor devices,
Even if a single extremely fine foreign substance adheres to the reticle surface, the wafer may be defective.

Conventionally, the surface of the reticle has been carefully inspected before performing reduction projection exposure, and reduction projection exposure apparatuses equipped with a foreign object inspection mechanism have also been developed and put into practical use.

[Problem that the invention seeks to solve]

However, in this type of reduction projection exposure apparatus,
Reduction projection exposure is performed using the reticle after the foreign object inspection is completed, so if the reticle is frequently replaced in a high-mix, low-volume production product, it takes a lot of time to inspect the reticle surface for foreign objects, and the reduction projection exposure device This had the disadvantage of lowering the operating rate.

SUMMARY OF THE INVENTION An object of the present invention is to provide a reduction projection exposure apparatus which eliminates the above-mentioned drawbacks and which does not reduce the operating rate even during high-mix, low-volume production.

[Means for solving problems]

The reduction projection exposure apparatus of the present invention includes a plurality of scanning holding plates that hold a reticle and are movable in a fixed direction, a plurality of foreign object detection means for detecting foreign objects on the surface of the reticle, and a plurality of foreign object detection means for projecting a pattern on the reticle. an illumination optical system, an illumination optical system selection means for selecting one desired illumination optical system and guiding the reticle pattern to the reduction lens, and a semiconductor wafer on which the reticle pattern from the reduction lens is transferred. It is configured to include an XY stage.

According to the present invention, while reduction projection exposure is being carried out, 1
Since the surfaces of more than one reticle are inspected, there is no need to wait for inspection of the reticle surfaces.

Therefore, the operating efficiency of the reduction projection exposure apparatus is greatly improved.

〔Example〕

Next, embodiments of the present invention will be described using the drawings.

FIG. 1 is a perspective view of an optical system for explaining one embodiment of the present invention.

In FIG. 1, the reduction projection exposure apparatus includes illumination optical systems 1a and lb for projecting a pattern on a reticle, including a mercury lamp, condenser lenses 2a and 2b, and a reticle 3a on which a pattern is formed.

3b, respectively, and are movable in a fixed direction, a reduction lens 5, an XY stage 7 on which a semiconductor wafer 6 is placed, a laser emitting unit 8, and a scanning reflector 9.
, foreign matter detection means 11JL, l consisting of scattered light detection section 10
lb, an illumination optical system selection means 14 consisting of movable light shielding plates 12&, 12b, and a movable reflection plate 13.

First, the reticle 3b with a pattern formed on its surface is set on the scanning holding plate 4b, and the foreign object detection means 11b is used to inspect the surface of the reticle 3b for foreign objects. That is, the laser beam 8a from the laser emitting unit 8 is irradiated onto the surface of the reticle 3b by the scanning reflector 9, and is scanned, for example, in the X-axis direction. On the other hand, since the scanning holding plate 4b is configured to be able to move stepwise in the Y-axis direction, the laser beam 8a is transmitted from the reticle to the reticle 3b.
The entire surface of the image is sequentially scanned. Then, the laser light scattered on the reticle surface is detected by the scattered light detection section 10, and the presence or absence of foreign matter on the surface of the reticle 3b is automatically determined.

In this way, for example, a pattern is projected onto the reticle 3a determined to be free of foreign matter using light from the illumination optical system 1a. At this time, the illumination optical system selection φ stage 14 simultaneously operates to guide this projection light 16 to the reduction lens 5. That is, the movable light shielding plate 12JIL moves upward and the movable reflection plate 13 moves to the right, guiding the projection light 16 of the pattern reflected by the reflection plate 15a to the reduction lens 5, and projecting it onto the wafer 6 on the XY stage 7. do. In this way, the reduced pattern is exposed onto the square 6.

In this way, in this embodiment, the reduction projection lens system, which is difficult to adjust, and the XY stage, which requires ultra-precise movement control, are shared, and since it is equipped with two foreign object detection means, an illumination optical system, etc., the reticle Inspection of foreign substances on the surface and projection exposure operation can be performed in parallel. As a result, the waiting time required to inspect the reticle surface for foreign matter as in the past is shortened, and the operating rate of the reduction projection exposure apparatus is greatly improved.

In the above embodiment, the case is explained in which two illumination optical systems, foreign object detection means, scanning holding plates, etc. are provided (one pair), but in order to eliminate the waiting time for foreign object inspection on the reticle surface, Of course, three or more of these may be provided.

In addition, in the above embodiment, two illumination optical systems were used, but since only one light source is required for projection reduction exposure,
It is also possible to project the reticle pattern by alternately selecting one light source using a reflecting mirror or the like. In this case, the device can be made more compact.

〔Effect of the invention〕

As described in detail above, according to the present invention, since a plurality of illumination optical systems and foreign object inspection means are provided, foreign object inspection on the reticle surface can be performed in parallel with the reduction projection exposure operation. . Therefore, even if the reticle is replaced frequently, the operating rate does not decrease, which has a great effect on improving the manufacturing efficiency of semiconductor devices.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an embodiment of the present invention. IJLllb...Illumination optical system, 2a, 2b...
...Condenser lens, 3a, 3b...Reticle, 4a, 4b...Scanning holding plate, 5...
...Reducing lens, 6...Queha, 7...
...XY stage, 8... Laser emitting section, 9.
...Scanning reflector, 10...Scattered light detection unit, lla, llb...Foreign object detection means, 12a,
12b...Movable light shielding plate, 13...Movable reflection plate, 14...Illumination optical system selection means, 15a
, 15b... Reflection plate, 16... Projection light.

Claims (2)

[Claims] (1) A plurality of scanning holding plates that hold a reticle and are movable in a fixed direction, a plurality of foreign object detection means that detect foreign objects on the surface of the reticle, and a plurality of illumination optical systems that project the pattern of the reticle. , an illumination optical system selection means for selecting one desired illumination optical system and guiding the reticle pattern to the reduction lens, and an XY stage on which the semiconductor wafer to which the reticle pattern from the reduction lens is transferred is placed. A reduction projection exposure apparatus comprising: (2) The plurality of illumination optical systems are illumination optical systems that alternately select and use light from a single light source.
) The reduction projection exposure apparatus described in item 2.