JPH01129414A - Inspection of photoresist pattern - Google Patents

Abstract

PURPOSE:To check the state of the formation of photoresist patterns extremely simply at low cost by simultaneously forming photoresist patterns for inspection, which are arranged at regular intervals in both the vertical direction and the lateral direction and line width of which is thinned gradually, near the desired photoresist patterns. CONSTITUTION:When a metallic film electrode film 2 is formed onto a wafer substrate 1, photoresists 3 are applied onto the surface of the film 2 and desired patterns are exposed and shaped onto the resist films 3 by using a photomask, photoresist patterns 4 for inspection are exposed onto the resist film 3 near the desired patterns by the photomask. When the photoresists in non-exposure sections are removed through processing after the exposure, the photoresist patterns 4 for inspection are shaped near the desired photoresist patterns together with the desired photoresist patterns.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention is applied to the manufacturing process of 5AW (surface acoustic wave) devices, magnetic pulp devices, etc., in which a photoresist is used to create a polar pattern, etc. on the surface of a substrate. The present invention relates to a method for inspecting a photoresist pattern used in forming a photoresist pattern.

(b)) Conventional technology In the SAW device etc. mentioned in the introduction, the so-called photolithography method K, which performs etching using a photoresist, is used.
An electrode pattern is formed on the substrate,
A method for forming such an electrode pattern is described, for example, in Japanese Patent Application Laid-open No. 60
It is described in Publication No.-59909 ([05)I3/10].

Incidentally, recently, as the application of these SAW elements to the GHz band has spread, the electrode width and electrode spacing have become gradually narrower, and therefore it has become necessary to form a photoresist pattern on the substrate with high precision, which serves as a mask when etching the electrode pattern. is required.

Therefore, conventionally, the optimal exposure conditions for obtaining a resist pattern of a predetermined width have been determined by optically measuring the pattern width and film thickness of the photoresist pattern after development.

(c) Problems to be Solved by the Invention However, in the conventional inspection method as described above, the pattern width that can be measured optically is relatively large, so it is difficult to accurately measure a pattern width of about 1 μm. I can't, and
The equipment was also large and expensive.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to propose an inspection method that does not require such expensive equipment and can moreover accurately check whether a resist pattern has a predetermined width.

B) Means for solving the problem In the present invention, when forming a desired photoresist pattern on a substrate, an inspection method is used in which line widths are gradually narrowed at regular intervals in both the vertical and horizontal directions near the desired photoresist pattern. The photoresist patterns were formed at the same time.

(e) Effect According to the 11G configuration as described above, when overexposed, even the thick part of the inspection pattern is removed by etching, and when underexposed, even the thin part of the inspection pattern is removed by etching. Since it remains without being removed, the formation state of the photoresist pattern can be checked using this inspection pattern.

(F) Example Hereinafter, an example of the present invention will be described with reference to the drawings. That is, in the present invention, the substrate for the sea urchin shown in FIG. 2(a)! After forming a metal film (electrode film) (2) on the surface of 11 as shown in Fig. 2 (mountain), a photoresist (3) is further applied on the surface as shown in Fig. 2 (C), and the resist film 13) When a desired pattern is formed by exposure using a photomask (not shown), the photoresist pattern (4) for inspection as shown in FIG. 1(a) or <b>(c) is formed using the photomask. is the resist film 13) near the desired pattern.
The top was exposed to light. Therefore, if the 7 photoresists in the non-exposed areas are removed by this post-exposure process as shown in FIG. will be formed.

Here, the inspection patterns shown in FIGS. 1(a) to 1(c) all have a shape in which the pattern width gradually becomes narrower at regular intervals in both the vertical and horizontal directions. Therefore, if you look at the inspection pattern that appeared after the above-mentioned phenomenon processing (FIG. 2(d)) and find that even the relatively thick parts (45), (44), etc. have been removed, it is likely that the overexposure has occurred. In addition, if sufficiently thin portions (4n-1) (4n), etc. remain, it can be determined that the exposure is insufficient. That is, in the overexposure state, the photoresist pattern width is smaller than a predetermined value, and in the underexposure state, the photoresist pattern width is larger than the predetermined value.

Note that FIG. 6 is a vertical cross-sectional view of the inspection photoresist pattern of FIG. 1(a) that appears due to the phenomenon.

(G) Effects of the Invention According to the present invention, the formation state of the 7-photoresist pattern can be checked at low cost and very easily without the need for any special measuring device.

[Brief explanation of the drawing]

Figures 1 (a), (b), and (c) are diagrams showing different actual sister examples of the inspection patterns used in the present invention, and Figure 2 (a).
-(d) are process diagrams for forming a photoresist pattern on a substrate, and FIG. 6 is a vertical sectional view of the substrate when the inspection pattern of FIG. 1(a) is formed. (IJ: Substrate, (2): Metal film, (3): Photoresist film, (4): Inspection pattern

Claims (1)

[Claims] (1) A method of inspecting whether a photoresist pattern formed on a substrate has a predetermined width, the method comprising A photoresist pattern for inspection whose line width gradually becomes narrower is formed simultaneously with the formation of the desired photoresist pattern, and the formation state of the photoresist pattern is inspected using this inspection pattern. inspection method.