JPS62194628A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To reduce the influence of loading effect on the occasion of a dry- etching, by forming a dummy photo resist pattern on a part where a spacing between photo resist patterns is relatively wide, and performing the dry-etching of a film to be etched applying the photo resist pattern and the dummy photo resist pattern as a mask. CONSTITUTION:A dummy photo resist pattern 4b is formed on a part where a spacing between photo resist patterns on a film to be etched is relatively wide. In the case where a dry-etching of the exposed part of an aluminum film 30 is selectively performed applying a photo resist pattern 4a and the dummy photo resist pattern 4b as a mask, the density of a pattern containing the photo resist pattern 4a and the dummy photo resist pattern 4b is made uniform, and so the plasma condition becomes uniform for the photo resist pattern 4a and the dummy photo resist pattern 4b. Thus the influence of loading effect is reduced, so that an aluminum wiring patterns 30a, 30b which have dimensional accuracy and contains no undercut can be formed on a base insulating film 2.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method of manufacturing a semiconductor device, and in particular, a method of forming a fine pattern by reducing the influence of the O-ding effect during dry etching of a film to be etched. It is related to.

[Prior Art] FIG. 3 is a plan view of a wafer after forming seven conventional photoresist patterns for forming an aluminum wiring pattern. In the figure, strip-shaped photoresist patterns 4a are randomly formed on an aluminum film 30, and there is a difference in the pattern density of the photoresist patterns 4a with respect to aluminum 1130.

FIG. 4 is a cross-sectional view of the wafer after dry etching the aluminum film. In fig.

A base insulation 11JI2 is formed on the substrate 1, and an aluminum wiring pattern 30a is formed on this base insulation llI2.
, 31a are formed. The aluminum wiring patterns 30a and 31a are formed by forming an aluminum film 30 on the base insulating pattern 2, and then forming 7 photoresist patterns 4a on the aluminum film 30.
It is formed by selectively dry etching the exposed portion of the aluminum 11130 using a as a mask.

[Problems to be Solved by the Invention] Conventional aluminum wiring patterns are formed by the method described above.
If a is formed randomly, an undercut 5 will occur in a part of the aluminum wiring pattern, for example, the aluminum wiring pattern 31a, due to the loading effect during dry etching due to the difference in pattern density of the photoresist pattern 4a, and this undercut will occur in a part of the aluminum wiring pattern 31a. There is a problem in that the amount of cutting differs between aluminum wiring patterns, making it difficult to form fine aluminum wiring patterns with precise dimensional control.

This invention was made in order to solve the above-mentioned problems, and it is a method for forming fine patterns on a film to be etched, which reduces the influence of the loading effect during dry etching of the film to be etched, and allows precise dimensional control. The purpose is to obtain a method.

[Means for Solving the Problems] A method for manufacturing a semiconductor device according to the present invention is a method for manufacturing a semiconductor device in which a desired pattern is formed by dry etching using a photoresist pattern formed on a film to be etched as a mask. In this method, prior to dry etching, a dummy photoresist pattern is formed in a portion where the spacing between photoresist patterns is relatively wide, and dry etching is performed using the photoresist pattern and the dummy photoresist pattern as a mask.

[Operation] In the present invention, dummy photoresist patterns are formed in areas where the spacing between photoresist patterns on the film to be etched is relatively wide.

The pattern density including the photoresist pattern and dummy photoresist pattern on the film to be etched is equalized, and the influence of the loading effect during dry etching of the film to be etched is reduced.

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

In addition, in the description of this first embodiment, the description of the parts that are related to the description of the prior art will be omitted.

FIG. 1 is a plan view of a wafer after forming seven photoresist patterns and a dummy photoresist pattern for forming an aluminum wiring pattern according to an embodiment of the present invention. The configuration according to this embodiment differs from the configuration shown in FIG. 3 in the following points.

That is, a band-shaped dummy photoresist pattern 4b is formed in a portion where the interval between the seven photoresist patterns 48 on the aluminum BI 30 is relatively wide, and the adjacent patterns of the photoresist pattern 4a and the dummy photoresist pattern 4h are The spacing between them is almost equal. For this reason, the pattern density including the photoresist pattern 4a and dummy photoresist pattern 4b for the aluminum 1130! The degrees are equalized compared to the configuration shown in FIG.

FIG. 2 is a sectional view of a substrate wafer on which the aluminum film is dry etched, according to an embodiment of the present invention.

In the figure, an aluminum f is shown using a photoresist pattern 4a and a dummy photoresist pattern 4b as masks.
When selectively dry etching the exposed portion of f1130, the pattern density including the photoresist pattern 4a and the dummy photoresist pattern 4b is equalized, so the plasma state for the photoresist pattern 4a and the dummy photoresist pattern 4b is becomes uniform, and the influence of loading effect becomes smaller. For this reason, all the base materials! Aluminum wiring patterns 30a and 30b without undercuts can be formed on 2 with good dimensional accuracy. Moreover, at this time, even if the aluminum wiring pattern 30a.

Even if an undercut occurs in the aluminum wiring pattern 30b, the undercut between the aluminum wiring patterns 30a and 30b can be kept small with high precision.

Although the above embodiment describes the case of forming an aluminum wiring pattern, the present invention can also be applied to the formation of fine patterns on other films such as silicon oxide films, and the same method as in the above embodiment can be applied to these cases as well. be effective.

[Effects of the Invention] As described above, according to the present invention, a dummy photoresist pattern is formed in a portion where the distance between the photoresist patterns is relatively wide, and a film to be etched is etched using the photoresist pattern and the dummy photoresist pattern as a mask. Since the film is dry etched, the influence of the loading effect during dry etching of the film to be etched can be reduced. Therefore, it is possible to obtain a method for forming a fine pattern on a film to be etched, which allows precise dimensional control.

[Brief explanation of drawings]

FIG. 1 is a plan view of a wafer after forming a photoresist pattern for forming an aluminum wiring pattern and a dummy photoresist pattern according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of a wafer having an aluminum film dry-etched according to an embodiment of the present invention. FIG. 3 is a plan view of a wafer after forming a conventional 7A tres 1 pattern for forming an aluminum wiring pattern. FIG. 4 is a cross-sectional view of a wafer after conventional dry etching of an aluminum film. In the figure, 1 is a substrate, 2 is an NPA base, 30 is an aluminum film, 4a is a photoresist pattern, 4b is a dummy photoresist pattern, 30a, 30b, 31
A is an aluminum wiring pattern, and 5 is an undercut. Note that the same reference numerals in each figure indicate the same or corresponding parts. Agent: Masuo Oiwa (Figure 1, Funeral Figure 2, Figure J: Underk, )

Claims (3)

[Claims] (1) In a method for manufacturing a semiconductor device in which a desired pattern is formed by dry etching using a photoresist pattern formed on a film to be etched as a mask, the distance between the photoresist patterns is adjusted prior to dry etching. A method for manufacturing a semiconductor device, comprising forming a dummy photoresist pattern in a relatively wide area. (2) The method for manufacturing a semiconductor device according to claim 1, wherein the film to be etched is an aluminum film. (3) The method of manufacturing a semiconductor device according to claim 1, wherein the film to be etched is a silicon oxide film.