JPH05175114A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To prevent skirting of a coating film and to suppress an irregularity in a size of a pattern in a lithographic step of forming the pattern by using a photosensitive coating film. CONSTITUTION:After the steps of (A) coating, (B) exposing and (C) developing a positive photosensitive film are conducted as prior art, only a substrate is wafer-cooled in a high temperature atmosphere thereby to set a temperature difference in a thickness direction of the film 3 (D). As a result, a high temperature region of the film is cured by irradiating with a UV to be solidified, a skirted part of the substrate is further exposed to be easily dissolved by developing. Thus, a photosensitive film pattern having no skirt can be formed (E).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a semiconductor device capable of improving dimensional accuracy when forming a pattern using a photosensitive coating film.

[0002]

2. Description of the Related Art Hitherto, in order to form a pattern, a lithographic technique has been used in which a photosensitive coating film is used to make use of a difference in properties between a portion irradiated with ultraviolet light and a portion not irradiated with ultraviolet light.

For example, as shown in FIG. 2 as a cross-sectional view of each step, a positive photosensitive coating film 3 is coated on a film 2 to be etched formed on a substrate 1 (A), and a mask 4 having a pattern is formed therebetween. When the ultraviolet light is irradiated, the property of the coating film 3 in the portion irradiated with the ultraviolet light changes corresponding to the mask opening (B). Therefore, when the developing process is performed, the unexposed portion 3D remains.

[0004]

By the way, in the above-mentioned lithographic technique, there is a region where the pass / fail of the photosensitivity is vague at the boundary between the unexposed and exposed portions. Generally, the coating film is as shown in FIG. In addition, a value slightly different from the desired dimension can be obtained by the shape obtained by subtracting the skirt 3E. This part causes dimensional variations because the method of pulling the soot differs depending on the subtle changes in the environment and the location.

[0005]

The present invention relates to a lithographic technique using a positive photosensitive coating film, in which a pattern once formed is cooled again in an appropriate ambient temperature and the entire surface is exposed again and developed. is there.

[0006]

According to the above method, the coating film in the vicinity of the substrate can be sufficiently removed by performing two exposures at a low temperature, and the tailing can be eliminated. On the contrary, the coating film on the upper side is irradiated with UV at a high temperature and is tightened and hardened, so that it does not decrease even in the second development.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

FIG. 1 is a process flow chart of the present invention. The same parts as the conventional ones are designated by the same reference numerals and the description thereof is omitted.
After exposing the coating film 3 applied as usual, development is performed until the substrate starts to be exposed (AC). After that, the wafer is placed on a plate 5 that can be cooled and the atmosphere is changed to 170 to 18
Raise to 0 ° C. When UV irradiation is performed again on the entire surface in this state, the high temperature portion 3C is hardened and becomes insoluble during development, and the substrate side 3B is forcibly cooled and kept at room temperature to perform overexposure (D). By developing this again, it is possible to form a pattern without trailing of the coating film (E).

[0009]

As described above, according to the present invention, the tailing of the coating film can be eliminated and the dimensional accuracy can be improved by appropriately performing the high temperature atmosphere and the substrate cooling after the development and performing the whole surface exposure again. .

[Brief description of drawings]

FIG. 1 is a sectional view of each step of a pattern forming method of the present invention.

FIG. 2 is a sectional view of each step of a conventional method.

[Explanation of symbols]

 1 Silicon substrate 2 Silicon oxide film (film to be etched) 3 Positive photosensitive coating film 3B Substrate side coating film 3C Cured coating film (high temperature part) 3D Coating film with tail 5 Wafer cooling table

Claims (2)

[Claims] 1. When forming a pattern using a positive photosensitive coating film, after the pattern is once formed, the substrate is cooled in a high temperature atmosphere, the positive photosensitive film is given a temperature gradient, and the whole surface is exposed again and developed. A method of manufacturing a semiconductor device, comprising: 2. The method of manufacturing a semiconductor device according to claim 1, wherein the high temperature atmosphere is 170 to 180 ° C., and the temperature of the cooled substrate is room temperature.