JP2990530B2 - Method for manufacturing semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] In a method of manufacturing a semiconductor device using an exposure process by a plurality of exposure devices incorporated in a wafer process line, the present invention relates to an improvement of improving pattern overlay accuracy. An object of the present invention is to provide an improvement in a method of manufacturing a semiconductor device using an exposure step by a plurality of exposure apparatuses to be incorporated, whereby the influence of distortion of the exposure apparatus is reduced and high overlay accuracy is obtained. In a method of manufacturing a semiconductor device in which a single wafer is sequentially exposed a plurality of times using a plurality of exposure apparatuses,
Exposure apparatuses used in each exposure step can be roughly classified into distortion aberration of the lens, whether the contour has a convex tendency bulging outward or a contour has a concave tendency bulging inward,
The exposure apparatus used in each exposure step is configured so that the above-mentioned tendency of distortion is the same.

[Industrial applications]

The present invention relates to a method for manufacturing a semiconductor device using an exposure process by a plurality of exposure apparatuses incorporated in a wafer process line, and to an improvement for improving pattern overlay accuracy.

[Conventional technology]

In a wafer process, generally, a plurality of exposure steps by a plurality of exposure apparatuses are required. At this time, it is necessary to superpose a pattern to be exposed on a pattern already formed on the wafer. Conventionally, not so high overlay accuracy was required, and the influence of the distortion of the exposure apparatus on the overlay accuracy could be neglected. Therefore, no special monitoring and management for distortion is performed.

[Problems to be solved by the invention]

However, as the degree of integration of semiconductor devices is improved and semiconductor devices are miniaturized, higher overlay accuracy is required, and a decrease in overlay accuracy due to distortion of an exposure apparatus causes a decrease in product yield. Has been a factor in lowering.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate this drawback, and to reduce the influence of distortion of an exposure apparatus in a method of manufacturing a semiconductor device using an exposure step by a plurality of exposure apparatuses incorporated in a wafer process line. Therefore, it is an object of the present invention to provide an improvement that enables a high overlay accuracy to be obtained.

[Means for solving the problem]

The object of the present invention is to provide a semiconductor device manufacturing method in which a plurality of exposure apparatuses are sequentially exposed to a single wafer by using a plurality of exposure apparatuses. However, it can be roughly classified into whether the contour has a convex tendency bulging outward or a contour has a concave tendency bulging inward, and the exposure apparatuses used in each exposure step have the same distortion as each other. This is achieved by a method of manufacturing a semiconductor device.

[Action]

The tendency of the distortion of the exposure apparatus is as shown in FIG.
It is roughly divided into two groups, Group A and Group B. In the case of projecting a 15 mm square field (angle of view) indicated by a dashed line in the figure, group A has a tendency that the center of each side is concave inward, and group B has a tendency to expand outward. ing. Since the amount d in which the center of each side is depressed inward or the amount d inflated outward is about 0.07 μm at the maximum, an exposure apparatus having a distortion tendency of Group A and an exposure apparatus having a distortion tendency of Group B When the patterns are superimposed by using (1) and (2), as shown in FIG. 2, a maximum displacement of 0.14 μm occurs at the center of each side.

Therefore, the distortion of all the exposure apparatuses is measured, and the exposure apparatus is divided into the apparatus having the distortion of the group A and the apparatus having the distortion of the group B, and each wafer process line belongs to the same group. If each exposure device is configured, the amount of misalignment can be reduced.
It can be reduced to within 0.07 μm.

〔Example〕

Hereinafter, a configuration of a wafer process line according to an embodiment of a method of manufacturing a semiconductor device according to the present invention will be described with reference to the drawings.

Referring to FIG. 1, the distortions of all the exposure apparatuses are measured, and the exposure apparatus belonging to the same group is divided into the group A having the distortion aberration tendency and the group B apparatus having the distortion tendency. Configure each process line.

〔The invention's effect〕

As described above, in the method of manufacturing a semiconductor device according to the present invention, since the exposure apparatus incorporated in the wafer process line has the same tendency of distortion, there is no countermeasure for the amount of positional deviation when performing overlay exposure. It can be halved compared to the case where no treatment is performed, which greatly contributes to the improvement of the product yield.

[Brief description of the drawings]

FIG. 1 is a diagram showing two types of distortion aberration tendencies of an exposure apparatus. FIG. 2 is a diagram showing the magnitude of positional deviation when patterns are overlapped using exposure apparatuses having different distortion aberration tendencies.

Claims (1)

(57) [Claims] 1. A method of manufacturing a semiconductor device, in which a plurality of exposure apparatuses sequentially expose a single wafer using a plurality of exposure apparatuses, wherein each of the exposure apparatuses used in each exposure step includes a lens distortion. However, it can be roughly classified into whether the contour has a convex tendency bulging outward or a contour has a concave tendency bulging inward, and the exposure apparatuses used in each exposure step have the same distortion as each other. A method for manufacturing a semiconductor device, comprising: