JPH055166B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for manufacturing a semiconductor device, and more particularly, to a method for forming electrodes and wiring patterns by performing wet etching after patterning a positive resist. , used in MOS-LSI semiconductor devices.

(Prior art) Conventional semiconductor devices use materials with high reflectivity such as Al, Al-Si alloy, and polycrystalline silicon as electrode and wiring materials, and the electrodes and wiring are formed in a photolithography process using a negative resist. It was forming a pattern.

However, in order to form fine electrodes and wiring patterns, it is necessary to perform a photolithography process using a positive resist that is less susceptible to the effects of reflection from the underlying layer.

(Problems to be Solved by the Invention) In the above method, there are countless protruding traces of gas generated by photoreaction or thermal decomposition of components of the positive resist between the underlying electrode material and the positive resist. It remains empty. Therefore, in wet etching, the etchant penetrates into this void, resulting in the electrode and wiring pattern a having a shape as shown in FIG. 3, which poses a problem in that fine linear electrode and wiring processing cannot be performed. In the figure, b is a wiring part, c is an electrode part, and d is a contact part. On the other hand, if dry etching (for example, plasma etching) is used instead of wet etching, fine and linear electrodes and wiring can be processed, but dry etching is expensive, resulting in an increase in manufacturing costs.

(Means for Solving the Problems) A method for manufacturing a semiconductor device according to the present invention involves forming a thin film that will become an electrode and a wiring pattern on an insulating film formed on a semiconductor substrate by wet etching after patterning a positive resist. After patterning the positive resist and before performing wet etching, the semiconductor substrate is immersed in an organic solvent or exposed to an atmosphere thereof;
Furthermore, heat drying is performed.

(Function) By immersing the semiconductor substrate in an organic solvent or exposing it to its atmosphere, and then thermally drying it, the gap created between the positive resist and the underlying thin film is filled.

(Example) The method for manufacturing a semiconductor device according to the present invention is described in the first example.
This will be explained with reference to the manufacturing process shown in Figures a to c.

(a) A thin film 3 is formed on an insulating film 2 such as SiO ₂ formed on a semiconductor substrate 1. As the material for the thin film 3, a material with high reflectance such as Al, Al-Si alloy, polycrystalline Si, etc. is used. On this thin film 3,
Apply positive resist, mask alignment, exposure,
A positive resist pattern 4 is formed through a series of photolithography steps such as development. At this time, between the resist pattern 4 and the thin film 3, protruding traces of gas generated by photoreaction or thermal decomposition of the components of the resist pattern 4 remain as countless voids 5, 5... See Figure a].

(b) Next, the semiconductor substrate 1 on which the resist pattern 4 is formed is subjected to a treatment such as immersing it in an organic solvent or exposing it to its atmosphere. As the organic solvent, xylene or N-butyl acetate can be used, as long as it can cause the resist to sag (or partially dissolve it).
As a result, the thermally stable material surrounding the resist pattern 4 is removed or altered. After that, heat drying is carried out, and the resist pattern 4 is sufficiently deformed at this temperature, and the air is dried.
Embed 5, 5... [See Figure 1b]. This thermal drying is performed by a conventional thermal drying process for improving the adhesion between the thin film 3 and the resist pattern 4.

(c) Next, the thin film 3 is etched by wet etching to form electrodes and wiring patterns 6 [see FIG. 1c].

The electrode and wiring pattern 6 thus formed are linear as shown in FIG.

(Effects of the Invention) As explained above, according to the method for manufacturing a semiconductor device according to the present invention, fine electrode and wiring processing, which was considered impossible except by dry etching, can be performed.
It can be performed by wet etching, which has good productivity and low cost, and is effective in improving yield.

[Brief explanation of drawings]

1a to 1c are process diagrams illustrating the method for manufacturing a semiconductor device according to the present invention, and FIG.
FIG. 3 is a plan view of a conventional electrode and wiring pattern. DESCRIPTION OF SYMBOLS 1...Semiconductor substrate, 2...Insulating film, 3...Thin film, 4...Resist pattern, 5...Void, 6...
...electrodes and wiring patterns.

Claims (1)

[Scope of Claims] 1. A method for forming a thin film serving as an electrode and wiring pattern on an insulating film formed on a semiconductor substrate by patterning a positive resist and then performing wet etching, comprising: patterning the positive resist; After that, before performing wet etching, the semiconductor substrate is immersed in an organic solvent or exposed to its atmosphere, and further heat-dried. 2. The method of manufacturing a semiconductor device according to claim 1, wherein the thin film is Al, Al-Si alloy, or polycrystalline Si.