JPH0582438A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To suppress the intensity variation of light caused by the interference between reflected light from the surface of a semiconductor substrate and incident light by providing a film composed of a material containing a dye below the uppermost resist film in a three-layer resist forming process. CONSTITUTION:After an aluminum film 2 having a film thickness of 1mum is formed on an interlayer insulating film 6 on a semiconductor substrate 1 having projections of lower-layer wiring 10, a resist film containing a dye at a high concentration of >=1% is formed to a film thickness of 2mum on the film 2 as a first-layer film 3 and the resist of the film 3 is changed in quality by UV curing so that the film 3 can withstand heat treatment of about 200-300 deg.C. Then an SOG film is formed on the film 3 to a film thickness of 2,000Angstrom as a second coating layer 4 and, on the film 4, a resist film 5 is formed to a film thickness of 0.8mum. Thereafter, the resist film 5 is patterned and the aluminum film is etched. Therefore, the reflected light from the surface of the semiconductor surface 1 can be reduced and the influence of the reflected light at the interface between the lower resist film and SOG film can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device manufacturing method, and more particularly to a three-layer resist process.

[0002]

2. Description of the Related Art A conventional method of manufacturing a semiconductor device is shown in FIG. The lower layer resist film 7 is formed on the semiconductor substrate 1 in which the interlayer film 6 is formed on the lower layer wiring 10 and the aluminum film 2 is formed thereon.
Then, it is hardened by a method such as hard baking and UV curing so that it can withstand the heat applied when the upper layer spin-on-glass SOG film 8 is formed. Next, an SOG film 8 is formed, an upper resist film 9 is formed thereon, and the upper resist film 9 is patterned into a desired pattern by using a photolithography technique. Then, the SOG film 8 is formed using the upper resist film 9 as a mask. Etching is performed using the reactive ion etching method (FIG. 2A). Next, after removing the upper resist film 9, the lower resist film 7 is etched using the SOG film 8 as a mask by the reactive ion etching method ((B) of FIG. 2). Next, after removing the SOG film, the aluminum film 2 is etched using the lower resist film 7 as a mask ((C) of FIG. 2).
After that, the lower resist film 7 is removed ((D) of FIG. 2).

[0003]

In the conventional method for manufacturing a semiconductor device, since the upper resist film is flattened by the lower resist film, the film thickness difference of the upper resist film is small, but the light absorption of the lower resist film is low. There is a problem that the light intensity fluctuates due to the interference between the reflected light from the semiconductor substrate surface and the incident light.

[0004]

A method of manufacturing a semiconductor device according to the present invention comprises a step of forming a coating film containing a dye on a surface of a semiconductor substrate having a step and forming a resist film on the coating film.

[0005]

The present invention will be described below with reference to the drawings. FIG. 1 is a vertical cross-sectional view of the process of the first embodiment of the present invention. Similar to the conventional example, the aluminum film 2 and the interlayer insulating film 6 are formed in a thickness of 1 μm on the surface of the semiconductor substrate 1 having the step of the lower layer wiring 10.
After the above formation, a resist film containing a dye in a high concentration of 1% or more is formed as the first layer film 3 to a thickness of 2 μm, and UV is formed.
After being modified by curing to withstand a heat treatment at about 200 to 300 ° C., an SOG film is formed as a second layer coating film 4 with a thickness of 2000 Å. Next, a resist film 5 is formed with a thickness of 0.8 μm (FIG. 1). Next, known resist patterning as shown in FIG. 2 is performed to etch the aluminum film.

Next, a second embodiment of the present invention will be described. Similar to the first embodiment, a resist film containing a high concentration of dye is formed, and after being cured by UV curing, an SOG film containing 1% or more of dye is formed as a second layer coating film 4. After that, the resist is patterned and etching is performed as in the conventional example. In this embodiment, since the SOG film also contains the dye, the reflected light from the surface of the semiconductor substrate is further weakened, and the influence of the reflected light at the interface between the lower resist film and the SOG film can be prevented.

[0007]

As described above, according to the present invention, in the three-layer resist process, the light reflected from the semiconductor substrate surface and the incident light are incident by flattening the semiconductor substrate surface by using the coating film containing the dye in high concentration. This has the effect of suppressing fluctuations in light intensity due to light interference.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

FIG. 2 is a vertical sectional view showing a conventional three-layer resist process flow.

[Explanation of symbols]

 1 Semiconductor Substrate 2 Aluminum Film 3 First Layer Coating Film 4 Second Layer Coating Film 5 Resist Film 6 Interlayer Film 7 Lower Layer Resist Film 8 SOG Film 9 Upper Layer Resist Film 10 Lower Layer Wiring

Claims (1)

[Claims] 1. A method of manufacturing a semiconductor device, wherein in a three-layer resist process, a film formed of a dye-containing material is provided below a top resist film.