KR930008128B1 - Method for preparation of semiconductor - Google Patents

Abstract

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Description

Inclined etching using wet etching

1a to d is an etching process chart using a conventional wet etching method.

Figure 1a is a diagram of a short fail-response state occurs in the corner of the pattern formed by conventional wet etching.

2a to g is an etching process chart using the wet etching method of the present invention.

* Explanation of symbols for main parts of the drawings

1: Sub Straight 2: Deposition Film

2a, 2b: etched pattern 3: photoresist

3a: Photoresist pattern after development 4: Photomask

5, 6: primary and secondary upper deposition films 7: dipping surface of the deposited film.

The present invention relates to an inclined etching method. In particular, the wet etching method is capable of performing an inclined etching by introducing a dipping treatment process to a wet etching process which can be performed only by conventional isotropy etching. It relates to a gradient etching method using the method. The conventional wet etching process is performed as shown in FIG. That is, as shown in FIG. 1A, a film 2 to be etched is deposited on the sub-straighter 1, and the photoresist 3 is photographed thereon, followed by exposure to ultraviolet light using a photomask 4 The photoresist is developed to form a photoresist pattern 3a as shown in FIG. 1B.

45°의 각을 가지고 형성되고, 이후 포토레지스트 패턴(3a)을 제거하면 서브 스트레이트(1)위에 제 1d 도에서와 같이 막의 패턴(2a)이 형성된다. 그런데 이와같은 종래의 습식식각 방법으로 패턴을 형성할 경우 제 1a 도와 같은 적층 구조에 있어서, 습식 식각된 패턴(2a)의 모서리 부분에서 위에 적층되는 1차 상부증착막(5)의 두께가 얇아지거나 스텝 커브리지(Step Coverage)가 불량한 상태가 발생하여 그위에 적층되는 2차 상부증착막(6)과 쇼트 페일(short failure) (제 1a 도 'A'부)을 발생시키며 특히 패턴(2a)가 메탈전극이고 1차 상부증착막(5)이 절연막일 경우 이 모서리 부분에서 2차 상부증착막(5)과의 브레이크 다운(Break down)이 발생되므로 소자 제조생산에 있어서, 수율을 감소시키는 원인이 되는 단점이 있었다.Then, as shown in FIG. 1C, a wet etching process is performed. Since isotropic etching is performed, Vs (cutting speed in the direction parallel to the surface of the resist and the material) and V _D (direction in the direction perpendicular to the surface of the material) are performed. Since the etching rate is almost the same, that is, V _S -V _D , the film pattern 2a is

It is formed at an angle of 45 degrees, and then the photoresist pattern 3a is removed to form a film pattern 2a on the sub straight 1 as shown in FIG. 1D. However, when the pattern is formed by the conventional wet etching method, in the laminated structure as shown in FIG. 1A, the thickness of the primary upper deposition film 5 laminated on the edge portion of the wet etched pattern 2a is thinned or stepped. A state of poor curvature (Step Coverage) occurs, which causes a second upper deposition film 6 and a short failure (a portion 'A' in FIG. 1A) to be stacked thereon. In particular, the pattern 2a is a metal electrode. When the first upper deposition film 5 is an insulating film, breakdown with the second upper deposition film 5 occurs at the corners, which causes a decrease in yield in device manufacturing and production. .

In order to solve the above disadvantages, the present invention is to allow the inclined etching by introducing a dipping treatment process into a conventional wet etching process capable of only isotropic etching.

Referring to FIG. 2, the manufacturing process according to the method of the present invention will be described in detail. First, the deposition film 2 is deposited on the sub-straighter 1 as shown in FIG. 2A, and then distilled water is used in an etching solution for etching the material. (1:10 to 1: 100) by diluting a large amount of deionize water (1:10 to 1: 100), and dipping the sample of FIG. 2a into a dipping dilute solution to make the surface 7 of the deposited film 2 porous as shown in FIG. 2b. And then apply the photoresist 3 as shown in FIG. 2c and then expose the photoresist by exposing ultra violet using the photomask 4 as shown in FIG. 2d. The same photoresist pattern 3a is formed. Then wet etching as in FIG. 2f shows that the surface 7 of the material 2 is porous due to the dipping process, and therefore Vs (in the direction parallel to the surface at the interface of the photoresist and the material). Etch rate is greater than V _D (etch rate in the direction perpendicular to the surface of the material), so that an inclined etch can be performed.

At this time, the corner angle of the formed material pattern 2b is about 15 ° to 25 °, and this value depends on the concentration of the dipping solution, the type of material, the type of dipping solution, and the etching temperature. Then, when the photoresist pattern 3a is removed, the material pattern 2b is formed on the sub straight 1 as shown in FIG. 2G.

Therefore, the present invention can make a pattern having a corner angle of about 15 ° to 25 ° by depositing a photoresist to a predetermined thickness after a dipping process during wet etching, so that step coverage when using a pattern formed by a conventional wet etching method is used. Since short failing due to defects and break downs can be prevented, reliability can be improved while improving the yield of device manufacturing and production.

Claims (2)

In the etching of the material using the wet etching method, the photoresist 3 is subjected to a dipping process using a dipping solution without directly applying the photoresist in a state in which the film 2 to be etched is deposited on the sub-straight 1. Inclined etching method using a wet etching method characterized in that the coating to be inclined etching. The dipping solution of claim 1, wherein the dipping solution is prepared by diluting the etching solution of the material to be etched and distilled water to 1:10 to 1: 100.

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