JPH03163452A - Formation of fine pattern - Google Patents

Abstract

PURPOSE:To form exact patterns with a fewer stages by forming a film covering photoresist patterns having apertures on a substrate surface on which the above- mentioned patterns are formed and removing the film exclusive of the parts formed in the side parts in the apertures. CONSTITUTION:The patterns consisting of the photoresist 12 are directly formed on the surface of the substrate 11 to be formed with the fine patterns. The suitable film 13, such as insulating film, is then deposited on the photoresist 12 from above the same by an ECR-CVD method. The rise of the substrate temp. is suppressed to, for example, <=100 deg.C in this method and, therefore, the film 13 can be directly deposited on the photoresist 12. The film 13 is removed exclusive of the parts formed in the side parts of the apertures of the photoresist after the deposition of the film 12. The removal of the film is executed perpendicularly to the substrate surface by, for example, reactive ion etching of strong anisotropy. The fine patterns consisting of the photoresist 12 and the film 13 are obtd. in such a manner.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of forming a fine pattern on a semiconductor substrate or the like.

[Conventional technology]

2. Description of the Related Art In the process of manufacturing semiconductor devices, fine patterns such as mask patterns are formed on semiconductor substrates.

When coating a semiconductor substrate with photoresist and exposing it to light using an exposure device to form a fine pattern on the semiconductor substrate, the miniaturization is limited by the exposure device, and the previous limit was about 0.5 μm. It becomes.

In order to overcome this limitation, a fine pattern forming method as shown in FIG. 2 has been proposed. In other words, the same figure (a
), first, an insulating film 2 is formed on the surface of a semiconductor substrate 1, and a photoresist pattern 3 is formed on this insulating film 2. Then, using the photoresist pattern 3 as a mask, the insulating film 2 in the pattern opening is removed by reactive ion etching (R I E), and the photoresist pattern is transferred to the insulating film 2 (see figure (b)).
. After this, the photoresist pattern 3 is removed (see figure (
(c)), and another insulating film 5 is deposited on top of the remaining insulating film 2 (see (d) in the same figure). Then, the insulating film 2
The gun rim film 5 is anisotropically removed by RIE or the like, leaving only the side wall portion of the opening, to obtain a fine pattern consisting of the insulating films 2 and 5. Through these steps, it is possible to obtain a fine pattern with an opening smaller than the photoresist pattern 3 by the amount of the insulating film 5 left as the sidewall portion.

[Problem to be solved by the invention]

However, in the method of forming a fine pattern shown in Fig. 2,
Not only was the fabrication process complicated, but the accuracy of pattern formation was also problematic. That is, as shown in the same figure (b),
When the insulating film 2 in the pattern opening is removed by reactive ion etching (RIE) using the photoresist pattern 3 as a mask and the resist pattern is transferred to the insulating film 2, the photoresist pattern 3 and RI formed first are removed.
This is because a size difference occurs between the patterns transferred to the insulating film 2 due to E.

Therefore, in view of the above-mentioned circumstances, an object of the present invention is to provide a method for forming a fine pattern that allows accurate pattern formation with a small number of steps.

[Means to solve the problem]

In order to achieve the above object, the fine pattern forming method according to the present invention includes a step of forming a film covering the photoresist pattern on the surface of the substrate on which the photoresist pattern having openings is formed by ECR-CVD method. and a step of removing the film leaving a portion formed on the side of the photoresist pattern opening.

[Effect]

By doing so, it becomes possible to attach the side wall directly to the side of the opening of the photoresist pattern.

〔Example〕

Embodiments of the present invention will be described below with reference to FIG.

FIG. 1 is a process diagram of a method for forming a fine pattern according to the present invention.

First, as shown in FIG. 2(a), a photoresist 1 is applied directly onto the surface of the substrate 11 on which a fine pattern is to be formed.
Form a pattern according to 2. Next, a suitable film 13 such as an insulating film is deposited on the photoresist 12 using the ECR-CVD method (see FIG. 2(b)). ECR-CVD
In this method, the increase in substrate temperature can be suppressed to 100° C. or less, so the film 13 can be deposited directly on the photoresist 12. After the film 13 has been deposited, the film 13 is removed leaving the portion formed on the side of the opening of the resist pattern (see FIG. 3(c)). This film 13 is removed perpendicularly to the substrate surface by, for example, highly anisotropic reactive ion etching.

Through these steps, the photoresist 12
A fine pattern consisting of the film 13 and the film 13 can be obtained, and the fine pattern thus obtained is finer than the initially formed resist pattern by the amount of the film 13 attached to the opening of the resist pattern as a side wall. It becomes something that has been transformed into something.

The method for forming a fine pattern according to the present invention described above can be applied to all processes that require a fine pattern, such as mask patterns used when forming trench capacitors in Si ICs and contact holes in wiring processes. It is.

〔Effect of the invention〕

As explained above, according to the present invention, by directly attaching the sidewall to the side of the opening of the photoresist pattern, the resist pattern is made finer than the initially formed resist pattern by the attached sidewall. It is possible to form patterns, and accurate patterns can be formed with fewer steps.

[Brief explanation of the drawing]

FIG. 1 is a process diagram showing an embodiment of the method of forming a fine pattern according to the present invention, and FIG. 2 is a process diagram of a conventional method of forming a fine pattern. 11...Substrate, 12...Photoresist, 13...
·film.

Claims (1)

[Claims] A method for forming a fine pattern on a substrate, the method comprising: forming a film covering the photoresist pattern on the surface of the substrate on which a photoresist pattern having an opening is formed by ECR-
A method for forming a fine pattern, comprising: a step of forming the film by a CVD method; and a step of removing the film, leaving a portion formed on the side of the opening.