JPH05267154A - Formation of resist pattern - Google Patents

Abstract

PURPOSE:To suppress a foaming phenomenon and realize a resist pattern excellent in resistance against etching. CONSTITUTION:A resist pattern is subjected to first thermal treatment at a temperature of approximately 110 deg.C after exposure and development. The pattern is then subjected to application of ultraviolet rays(UV) while a temperature is being raised from a second temperature (70 deg.C) lower than the first thermal treatment temperature as second thermal treatment. At first at a temperature of 70 deg.C, weak ultraviolet rays are applied to perform thermal treatment for a constant time. Then the treatment temperature is gradually raised while strong ultraviolet rays are applied, the application is stopped during the temperature rise, further the temperature is raised to 140 deg.C, and thermal. treatment is performed for a constant time at that temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a resist pattern used in a semiconductor device manufacturing process or the like.

[0002]

2. Description of the Related Art Conventionally, an ultraviolet irradiation heating method has been used to improve the etching resistance of a resist. The conventional ultraviolet irradiation heating method will be described below.

FIG. 4 is a processing condition diagram showing an ultraviolet irradiation heating method in a conventional resist pattern forming method. The resist pattern is formed by exposure and development.
It is processed at a temperature of 10 ° C. (not shown in FIG. 4).
After that, as shown in FIG. 4, while irradiating with ultraviolet rays (UV), the resist was cured by performing a temperature rising process from 130 ° C. to 200 ° C., for example.

FIG. 5 is a sectional view showing an example of a resist pattern. Reference numeral 1 is a substrate made of silicon or the like, and 2 is a resist pattern formed on the surface of the substrate 1.

[0005]

In the conventional ultraviolet irradiation heating method as shown in FIG. 4, bubbles 6 are generated in the resist pattern when the organic solvent component 4 in the resist is released as shown in FIG. There was a problem to do.

The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a method of forming a resist pattern which can suppress the foaming phenomenon and cure the resist without changing the shape.

[0007]

To achieve this object, a method of forming a resist pattern according to the present invention comprises a step of treating a resist pattern formed on a substrate by exposure and development at a first temperature, From a second temperature lower than the first temperature, the step of irradiating with ultraviolet rays during the treatment while increasing the temperature to the third temperature, the irradiation of the ultraviolet rays is a temperature lower than the first temperature. It is characterized by starting with.

[0008]

By performing the treatment under the above conditions, it is possible to suppress the bubbling phenomenon and the shape deterioration of the resist and to improve the etching resistance.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a processing condition diagram showing a method of forming a resist pattern in one embodiment of the present invention. FIG. 3 is a cross-sectional view showing an example of a resist pattern processed in this embodiment. Also in this embodiment, the resist pattern is subjected to the first heat treatment at a temperature of about 110 ° C. after exposure and development (not shown in FIG. 1). A normal positive photoresist was used as the resist, and the film thickness when the resist was applied was 2.0 μm.

Then, as the second heat treatment, the temperature of the second heat treatment (110 ° C.) lower than the second temperature (70 ° C.) is raised, and the surface of the resist is cured by irradiation with ultraviolet rays (UV). Then, the organic solvent component 4 in the resist is released by heating and cured. At this time, the release rate of the organic solvent component 4 and the curing rate of the resist are governed by the heating temperature. When the heating temperature is high, it is shielded by the resist of the semi-cured surface layer by irradiation of the ultraviolet rays 5, and the release rate from the surface. The organic solvent component 4 is vaporized inside earlier, and bubbles 6 are generated in the resist. Therefore, the resist 2 is cured without generating bubbles 6 by controlling the release rate of the organic solvent component 4 by lowering the heating temperature at least at the time of starting the irradiation of ultraviolet rays to be lower than the temperature of the first heat treatment step. be able to.

Further, in this embodiment, first, heat treatment is carried out at a temperature of 70 ° C. for a certain time while irradiating weak ultraviolet rays. During the treatment with weak ultraviolet rays, the curing of the resist surface does not proceed so much so that the organic solvent components inside are easily released and no bubbles are generated inside. Then, the treatment temperature is gradually raised while irradiating strong ultraviolet rays, the irradiation of ultraviolet rays is stopped in the middle of the temperature rise, and the temperature is further raised to 140 ° C., and then heat treatment is performed at that temperature for a certain period of time.

FIG. 2 is a processing condition diagram of a resist pattern forming method according to a second embodiment of the present invention. In this embodiment, first, heat treatment is performed at a temperature of 70 ° C. for a certain period of time while irradiating weak ultraviolet rays. During the treatment with weak ultraviolet rays, the curing of the resist surface does not proceed so much so that the organic solvent components inside are easily released and no bubbles are generated inside. Then, the treatment temperature is gradually raised while irradiating strong ultraviolet rays, and after raising the temperature to 140 ° C. for about 5 seconds, the ultraviolet ray irradiation is stopped and heat treatment is performed at that temperature for a certain period of time.

The resist pattern formed under the above two conditions did not show any deterioration in shape or the generation of bubbles inside, and was used as a mask pattern for dry etching of an aluminum layer having a film thickness of 1.5 μm. The result was obtained.

[0015]

As described above, according to the present invention, by setting the heating temperature at the time of irradiating ultraviolet rays to be lower than the temperature of the heat treatment just before that, the bubbling phenomenon is suppressed and the resist is cured without changing the shape. A high-quality resist pattern having excellent etching resistance is formed, which makes it possible to manufacture a semiconductor device or the like with excellent miniaturization, high yield, and high quality.

[Brief description of drawings]

FIG. 1 is a processing condition diagram of an embodiment of the present invention.

FIG. 2 is a processing condition diagram of another embodiment of the present invention.

FIG. 3 is a sectional view showing an example of a resist pattern.

FIG. 4 Diagram of conventional processing conditions

FIG. 5 is a sectional view showing an example of a resist pattern.

[Explanation of symbols]

 1 substrate 2 resist pattern 4 organic solvent component 5 ultraviolet light

Claims (1)

[Claims] 1. A step of treating a resist pattern formed on a substrate by exposure and development at a first temperature, and heating from a second temperature lower than the first temperature to a third temperature. And a step of irradiating ultraviolet rays during the treatment, and the irradiation of the ultraviolet rays is started at a temperature lower than the first temperature.