JPH01137634A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To improve dry etching resistant properties of a resist layer by a method wherein, after a resist pattern obtained by resist coating, exposure and development is subjected to whole surface exposure, the resist pattern is treated in gas containing Si. CONSTITUTION:An Al layer 2 is formed on the insulating film of an Si substrate 1 and a positive type photoresist layer 3 is applied to the layer 2. A required resist pattern is obtained by exposure and development. After whole surface exposure 4 is performed, the resist pattern is baked in gas containing Si at 80 deg.C for 5 minutes to form a silylated part 3-a in the surface of the resist layer 3. After post-baking is carried out at 120 deg.C for 4 minutes properly, dry etching is carried out. With this constitution, dry etching resistant properties of the resist layer 3 can be improved.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a method for manufacturing a semiconductor device, and in particular is used when forming a fine pattern using a photoresist and performing dry etching. It is something.

(Prior Art) Conventionally, in the photolithography process during the manufacture of semiconductor devices, a resist pattern is formed by resist coating, exposure, and development, and then a post bake is performed.
Next, dry etching is performed. In this case, the selectivity ratio in dry etching (=etching speed of workpiece material/etching speed of resist) is sufficiently large (
However, processing accuracy and throughput are worsening. On the other hand, even if curing treatment using deep ultraviolet light or ultraviolet light is performed, deterioration of the resist shape during dry etching can be prevented, but the selectivity does not improve. (Problems to be Solved by the Invention) The easiest way to solve the above problems is to increase the thickness of the resist film. There are problems such as an increase in the exposure energy required.

Furthermore, a multilayer resist process can be cited as a method of increasing the film thickness without reducing resolution, but the process becomes complicated and there are problems in terms of cost and throughput.

An object of the present invention is to improve the selectivity during dry etching by performing a simple process after forming a resist pattern.

(Means and effects for solving the problems) The present invention involves applying a photoresist onto a semiconductor substrate, exposing it to light for pattern formation, and developing it. After forming a resist pattern, the entire surface is exposed to light. This method of manufacturing a semiconductor device is characterized in that the resist is exposed to a gas containing Si and then dry etched. That is, in the present invention, after fully exposing a resist pattern obtained by resist coating, exposure, and development, the resist surface is silylated (the Si-containing gas diffuses and forms a base polymer) by treating it in a Si-containing gas. (combining with the resist) to improve the dry etching resistance of the resist.

(Example) An example of the present invention will be described below with reference to FIG. First, on the insulating film of the 5iJJ board 1, an AJL (A, ! alloy) layer 2 is formed to a thickness of 1.0 μm, and a positive photoresist [for example, NPR-820 (manufactured by Nagase Sangyo Co., Ltd.)] is applied thereon. ] 3 to a thickness of 1.4 μm (Figure 1 (a))
Exposure and development are performed to obtain a predetermined resist pattern (FIG. 1(b)).

Furthermore, full-surface exposure 4 with an energy amount of 3011J/(J[
For example, HMSD in a gas containing Si.
(Hexamethylene disilazane) Baking treatment was performed at 80° C. for 5 minutes in an atmosphere to form a silylated portion 3-a on the surface of the resist 3 (Fig. 1 (1)).
Then, after suitably post-baking at 120° C. for 4 minutes, dry etching is performed (FIG. 1(e)). When dry etching was carried out in this manner, the selectivity ratio was 2.46 in the case of only the conventional post bake, whereas the selectivity ratio was 3.12 in the case of the above-mentioned process, which was a good result.

As the above-mentioned treatment, the resist 3 may be simply exposed to a gas containing Si;
It is preferable to carry out the process in an atmosphere of This is because the effect is weak at temperatures below 80°C, and the resist pattern is deformed at temperatures above 150°C.

[Effects of the Invention] According to the present invention, the dry etching resistance of the resist can be improved through simple processing, and the processing accuracy and
It has the effect of improving throughput.

[Brief explanation of the drawing]

FIG. 1 is a process diagram of an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1...Semiconductor substrate, 2...Work material, 3...Resist, 3-a...Silylated portion, 4...Light for whole surface exposure.

Claims (4)

[Claims] (1) A photoresist is applied onto a semiconductor substrate, exposed and developed to form a pattern, and after a resist pattern is formed, the entire surface is exposed, and the resist is further exposed to gas containing Si. 1. A method for manufacturing a semiconductor device, which comprises performing dry etching after dry etching. (2) The method for manufacturing a semiconductor device according to claim 1, wherein HMDS (hexamethylene disilazane) is used as the Si-containing gas. (3) When exposed to the above Si-containing gas, 80°C to 1
The method for manufacturing a semiconductor device according to claim 1, characterized in that heat treatment is performed at 50°C. (4) The method for manufacturing a semiconductor device according to claim 1, wherein the material to be processed by the dry etching is an Al or Al alloy film.