JPH05275302A - Resist pattern formation method - Google Patents

Abstract

PURPOSE:To obtain a resist pattern having clear end face profile and no burr or reverse taper by performing a processing for making the primary exposed part of photoresist insoluble to developer and then performing secondary exposure with negative and positive photomasks being inverted thereafter performing the development. CONSTITUTION:A substrate 1 is supplied with positive photoresist 2 which is then primarily exposed by ultraviolet ray through a positive photomask 41. Primarily exposed part 31 is then made insoluble to developer through processing with amine gas. Secondary exposure is then performed by ultraviolet ray 5 through a negative photomask 42, i.e., an inverted photomask of the positive photomask 41. Secondarily exposed part 32 is soluble to the developer. After performing development, a resist pattern 6 is left. Since reverse tapers produced, respectively, through primary and secondary exposure at the end face of pattern are offset each other, a resist pattern having clear end face profile and no burr or reverse taper can be formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resist pattern forming method using a lift-off process.

[0002]

2. Description of the Related Art As a conventional resist pattern forming method of this type, there is a method as shown in FIG.

In the method shown in FIG. 3, (a) the photoresist 2 coated on the substrate 1 is pattern-exposed with a photomask 4 and ultraviolet rays 5, and (b) monochlorobenzene treatment is performed and then development treatment is performed. (C) Exposed part 3
A resist pattern 6 is formed by dissolving and removing.

The method shown in FIG. 5 is a method called an image reverse method. (A) A substrate 1 is coated with a positive photoresist 2 and the positive photoresist 2 is primarily exposed with a positive photomask 4 and ultraviolet rays 5. After that, (b) the primary exposed portion 31 is made insoluble in the developing solution by treating with an amine-based gas. After that, (c) by performing a secondary exposure for exposing the entire surface of the resist and then performing a developing treatment,
(D) A resist pattern 6 is formed by dissolving and removing the portion 32 other than the primary exposed portion 31. Although the primary exposed portion 31 becomes soluble in the developing solution by exposure, this soluble portion becomes unnecessary in the developing solution due to the treatment with the amine-based gas. Left behind.

After forming the resist pattern 6 as described above, as shown in FIG. 4 or 6, (a) the electrode material 7 is vapor-deposited on the entire surface, and (b) the resist pattern 6 is formed.
A predetermined electrode pattern 8 can be formed by removing only the upper electrode material together with the resist.

The above-mentioned resist pattern forming method is disclosed in, for example, "Nikkei Electronics 198" published by Nikkei BP.
July 25, 8 issue no. 452 ”, pp. 179-187, for forming thin film electrodes of display panels.

[0007]

However, according to such a structure, unnecessary burrs and reverse taper remain on the end face of the resist pattern 6, which makes it impossible to form an electrode pattern having good characteristics, for example. There was a problem.

The above problem occurs for the following reasons. That is, in the method shown in FIG. 3, unnecessary burrs 61 project on the end surface of the resist pattern 6. This burr 61
Occurs because the surface of the resist becomes slightly soluble in the developing solution due to the monochlorobenzene treatment. The presence of the burr 61 leaves a floating portion 81 at the end of the electrode pattern 8 as shown in FIG.

According to the method shown in FIG. 5, the end surface of the resist pattern 6 has an inverse tapered shape 62. For this reason,
As shown in FIG. 6, the vapor deposition material or the like that forms the electrode 8 wraps under the inverse tapered shape 62, and the wrapping material 82
Has an adverse effect on electrical characteristics.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a resist pattern forming method capable of obtaining a pattern having a clean end face shape without leaving unnecessary burrs and reverse taper. ..

[0011]

In order to solve the above-mentioned problems, the present invention performs a primary exposure for selectively exposing a photoresist with a photomask, and a treatment for making the primary exposed portion insoluble in a developing solution. After that, a second exposure is performed to selectively expose the portions other than the above-mentioned primary exposure portion by a photomask with the negative and positive inverted, and then a developing treatment is performed to dissolve and remove the portion that has become soluble in the developer by the exposure. , Is provided.

[0012]

According to the present invention, by the above-described structure, the reverse taper tendency of the pattern end surface caused by the primary exposure and the reverse taper tendency of the pattern end surface caused by the secondary exposure are canceled in the opposite directions, and the pattern end surface can be oriented in any direction. Moreover, since the vertical surface does not exhibit a taper tendency, it is possible to form a pattern having a clean end surface shape without leaving unnecessary burr and reverse taper.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

In the drawings, the same reference numerals indicate the same or corresponding parts. FIG. 1 shows a schematic process of a resist pattern forming method according to an embodiment of the present invention, in which 1 is a substrate for forming a pattern such as a thin film electrode, 2 is a positive photoresist, 31 is a primary exposure portion,
32 is a secondary exposure portion, 41 is a positive photomask, 42 is a negative photomask obtained by inverting the positive photomask 41, 5 is ultraviolet light for exposure, and 6 is a resist pattern to be finally formed.

The method shown in FIG. 1 is an application of the image reverse method, and pattern formation is performed by the following steps (a to d).

(A) A positive photoresist 2 is applied to the substrate 1, and the positive photoresist 2 is applied to the positive photomask 4
1 and UV 5 are used for primary exposure. The resist portion 31 selectively exposed by this primary exposure becomes insoluble in the developing solution.

(B) Treatment with an amine-based gas is performed to make the primary exposed portion 31 insoluble in the developing solution. As a result, the primary exposed portion 31 becomes insoluble in the developing solution.

(C) Secondary exposure is performed by using a negative photomask 42 which is the reverse of the positive photomask 41 and ultraviolet rays 5. The second exposed portion 32 becomes soluble in the developing solution.

(D) A developing treatment is carried out to dissolve and remove the soluble portion in the developing solution. As a result, the resist pattern 6 in which the portion 32 other than the primary exposed portion 31 is dissolved and removed remains.

In the resist pattern 6 formed in the steps (a to d) described above, the reverse taper tendency 621 of the pattern end surface caused by the primary exposure and the reverse taper tendency 622 of the pattern end surface caused by the secondary exposure are opposite to each other. Offset
The end surface of the pattern becomes a vertical surface that does not show a taper tendency in any direction. This makes it possible to form the resist pattern 6 having a clean end surface shape without leaving unnecessary burrs and reverse taper.

FIG. 2 shows a step of forming a thin film electrode pattern using the resist pattern 6 formed by the above-mentioned method as a mask. (A) After the electrode material 7 is deposited on the entire surface, (a) b) By removing only the electrode material on the resist pattern 6 together with the resist, the predetermined electrode pattern 8 can be formed. Since the end surface of the resist pattern 6 is formed substantially vertically in the electrode pattern 8 formed here, there is no rising or wraparound, and good electrical characteristics can be exhibited.

[0022]

As is apparent from the above description, according to the present invention, the primary exposure for selectively exposing the photoresist with the photomask is performed, and after the primary exposed portion is treated to be insoluble in the developing solution. By performing a second exposure for selectively exposing the portions other than the above-mentioned primary exposure portion with a photomask in which the negative and positive are reversed, and then performing a developing treatment for dissolving and removing the portion which has become soluble in the developer,
The reverse taper tendency of the pattern end surface generated in the primary exposure and the reverse taper tendency of the pattern end surface generated in the secondary exposure are canceled in the opposite directions, so that the pattern end surface exhibits a vertical surface that does not show a taper tendency in any direction. Therefore, there is an effect that it is possible to form a pattern having a clean end face shape without leaving unnecessary burr and reverse taper.

[Brief description of drawings]

FIG. 1 is a schematic process diagram of a resist pattern forming method according to an embodiment of the present invention.

FIG. 2 is a schematic process diagram of electrode pattern formation performed using the resist pattern formed in FIG.

FIG. 3 is a schematic process diagram of a conventional resist pattern forming method.

FIG. 4 is a schematic process drawing of electrode pattern formation performed using the resist pattern formed in FIG.

FIG. 5 is a schematic process diagram of a resist pattern forming method by a conventional image reverse method.

FIG. 6 is a schematic process diagram of electrode pattern formation performed using the resist pattern formed in FIG.

[Explanation of symbols]

 1 Substrate 2 Positive Photoresist 31 Primary Exposure Part 32 Secondary Exposure Part 41 Positive Photomask 42 Negative Photomask 5 UV for Exposure 6 Resist Pattern 7 Electrode Material 8 Electrode Pattern

Claims (1)

[Claims] 1. A primary exposure step of selectively exposing a photoresist coated on a substrate with a photomask, a treatment step of making the primary exposed portion insoluble in a developing solution, and the primary exposure using a negative-positive inverted photomask. A method for forming a resist pattern, which comprises performing a secondary exposure step of selectively exposing a portion other than a portion, and a developing treatment step of dissolving and removing a portion that has become soluble in a developing solution after the secondary exposure step.