JP2737256B2 - Method for manufacturing semiconductor device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device, and more particularly to a method for forming a pattern of a film having a high reflectance.

[Conventional technology]

As a conventional method of patterning a high-reflectance film, an anti-reflection film is formed on the high-reflectance film on the surface of the semiconductor substrate, a photoresist is applied thereon, and the photoresist is exposed by mask exposure. Using a patterned photoresist as a mask, the step of simultaneously etching the antireflection film and the underlying high-reflectance film was performed.

[Problems to be solved by the invention]

In the above-described conventional method of patterning a film having a high reflectivity, the thickness of the resist at the bottom of the step, such as the scribe line region, is thicker than the region having the pattern to be formed. In order to completely remove the resist at the bottom of the step such as the region by exposure and development, an exposure amount much larger than the optimum exposure amount in the region where the pattern is to be formed is required. Therefore, the formed pattern has a drawback that the dimension from the mask is conspicuous and line width control becomes difficult.

[Means for Solving the Problems] A method of manufacturing a semiconductor device according to the present invention includes a step of forming an antireflection film on a film having a high reflectance formed on a semiconductor substrate, and at least a step of forming an antireflection film in a scribe line region. Selectively etching and removing the anti-reflection film, and then simultaneously patterning the anti-reflection film and the film having high reflectance.

〔Example〕

 Next, the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of a semiconductor chip for explaining a first embodiment of the present invention.

First, as shown in FIG. 1A, after forming a field oxide film 7 and a gate polysilicon 6 on a semiconductor substrate 10, a first interlayer film 4 is formed. Next is the second polysilicon 5
Is formed, a second interlayer film 3 is formed. Next, after patterning the second interlayer film 3, a wiring material, for example, an aluminum alloy film 2 is formed, and when patterning, the scattered light is notched in the photoresist pattern due to a high surface reflectance. It may have an adverse effect. Therefore, a sputtered Si film or a plasma oxide film, for example, is formed on the surface of the aluminum alloy film 2 as the antireflection film 1.

Next, as shown in FIG. 1B, patterning of a photoresist 8 for etching and removing the anti-reflection film 1 in the scribe line region 9 is performed in advance, and the anti-reflection film 1 is removed only at the step portion.

Next, as shown in FIG. 1 (c), after removing the photoresist 8, a mask made of the photoresist 8A is formed again, and the wiring material 2 and the antireflection film 1 are patterned to form wiring.

At this time, the resist film thickness of the scribe line region 9 also having a large step is about 1 μm or more thicker than the region where the pattern is to be formed, but the portion has no antireflection film and the wiring material 2 having high reflectivity is exposed. Therefore, even if the entire surface is exposed at once, the photoresist absorbs approximately two to three times more light than the region where the antireflection film 1 covers the surface. When forming a wiring pattern with an exposure amount that reproduces
There is no fear that the photoresist remains in the scribe line region 9. Since the antireflection film and the wiring material can be simultaneously etched using the photoresist pattern thus formed as a mask, the mask dimensions can be transferred with good reproducibility.

FIG. 2 is a sectional view of a semiconductor chip for explaining a second embodiment of the present invention.

After performing the same processing as in the first embodiment shown in FIG. 1A, the antireflection film 1 and the wiring material 2 in the scribe line region 9 are simultaneously etched and removed as shown in FIG.

As described above, in the second embodiment, since the thick wiring material in the step portion such as the scribe line region is also etched in advance, the amount of over-etching in the etching of the wiring pattern can be extremely reduced. There are advantages.

Further, since the wiring material of the step portion has already been removed by etching at the time of patterning of the wiring pattern, even if the photoresist remains on the step portion, it can be ignored. Reproduction of the mask dimensions becomes easy.

In the above embodiment, the case where the anti-reflection film in the scribe line area is removed has been described. However, the present invention is not limited to this, and the anti-reflection film in the area where there is no pattern to be formed with the scribe line area is removed. You may.

〔The invention's effect〕

As described above, the present invention performs etching of the antireflection film at least in the scribe line region first,
By patterning a wiring pattern made of a film having a high reflectivity, there is an effect that a dimension is reduced from a mask dimension in a lithography process from resist patterning to etching, and pattern processing with good dimension reproducibility can be performed.

[Brief description of the drawings]

FIGS. 1 and 2 are cross-sectional views of a semiconductor chip for explaining the first and second embodiments of the present invention. DESCRIPTION OF SYMBOLS 1 ... Anti-reflection film, 2 ... Wiring material, 3 ... Second interlayer film, 4 ... First interlayer film, 5 ... Second polysilicon, 6 ...
... gate polysilicon, 7 ... field oxide film, 8 ...
... photoresist, 9 ... scribe line area, 10 ... semiconductor substrate.

Claims (1)

(57) [Claims] An anti-reflection film is formed on a film having a high reflectance formed on a semiconductor substrate, and at least the anti-reflection film in a scribe line region is selectively removed by etching. Patterning a film and a film having high reflectivity at the same time.