Method for forming transparent conductive film using chemically amplified resist

• US 6,632,115 B1
• Filed: 08/17/2001
• Issued: 10/14/2003
• Est. Priority Date: 12/10/1998
• Status: Expired due to Term

• Current Assignee: AU Optronics Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Miyamoto, Takashi, Tsujimura, Takatoshi
• Primary Examiner(s): Ramsey, Kenneth J.
• Application Number:
  US09/857,654
• Time in Patent Office: 788 Days
• Field of Search: 445/24, 430/313
• US Class Current: 445/24
• CPC Class Codes: G02F 1/13439 characterised by their electrical, optical, physical properties; materials therefor; method of making
• CPC Class Codes: H01L 21/32139 using masks
• CPC Class Codes: H01L 31/1884 Manufacture of transparent electrodes, e.g. TCO, ITO
• CPC Class Codes: H05K 1/0269 for visual or optical inspection
• CPC Class Codes: H05K 3/064 Photoresists
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy

Abstract

A method for patterning an indium-tin-oxide (ITO) film by using a chemically amplified resist, causing no resist separation nor adhesion degradation even if the ITO film is exposed to white light after the resist development. An amorphous ITO film is formed on a wafer. A negative chemically amplified resist is applied directly to the ITO film, and the resist film is exposed and developed. The structure having a resist pattern on the amorphous ITO film is free from resist separation and adhesion degradation even if the resist pattern is exposed to white light, and therefore the later manufacturing steps are not adversely affected, enabling proper visual inspection. After the structure is judged to be acceptable at the visual inspection, the amorphous ITO film is etched using the resist pattern as a mask, and then the resist pattern is removed. The ITO film is heated over the crystallization temperature of the ITO to form a crystallized ITO pattern having a chemical-resistance and a good electrical conductivity.

Claims

1. A process for forming an ITO film, comprising the steps of:

preparing an amorphous ITO film onto a substrate;

providing a negative chemically amplified photosensitive material directly onto said amorphous ITO film, and exposing and developing said negative chemically amplified photosensitive material to form a pattern of said negative chemically amplified photoresist; and

treating said amorphous ITO film through said pattern used as a mask.

2. The process according to claim 1, wherein the step of treating said amorphous ITO film comprises a step of removing a part of said amorphous ITO film which is not covered with said pattern.

3. The process according to claim 2, wherein the step of removing said amorphous ITO film comprises a step of bringing the part of the amorphous film ITO which is not covered with the pattern into contact with acid selected from the group consisting of oxalic acid, phosphoric acid and sulfuric acid.

4. The process according to claim 1, said process further comprising a step of removing said pattern.

5. The process according to claim 1, said process further comprising a step of heating said amorphous ITO film to microcystallize said amorphous ITO film.

6. The process according to claim 1, wherein said negative chemically amplified photosensitive material comprises phenolic novolak, methylol melamine and a photo-acid generator.

7. Process according to claim 6, wherein said photo-acid generator is triazines.

8. A process for forming a transparent oxide conductive film of, comprising the steps of:

preparing an amorphous film of said oxide onto a substrate;

providing a negative chemically amplified photosensitive material directly onto said amorphous film, and exposing and developing the negative chemically amplified photosensitive material to form a pattern; and

treating said amorphous film by said pattern used as a mask.

9. The process according to claim 8, said process further comprising a step of heating said amorphous film to microcrystalliie said amorphous film.

10. The process according to claim 8, wherein the oxide comprises ITO.

11. A structure including transparent conductive oxide film which is formed by the process of claim 8.

12. A process for inspecting a resist pattern on a substrate,

characterized in that said substrate has an amorphous ITO film;

said resist pattern includes a negative chemically amplified photosensitive material, said resist pattern being provided directly on said amorphous ITO film;

the negative chemically amplified photosensitive material contains a photo-acid generator; and

the inspection is performed under a light including an absorption spectrum of the photo-acid generator.

13. The process according to claim 12, wherein said light includes a spectrum having a wavelength of approximately 380 nm or less.

14. A process for manufacturing a flat panel display with an ITO film, comprising the steps of:

depositing an amorphous ITO film onto a substrate;

providing a negative chemically amplified photosensitive material directly onto said amorphous ITO film, and exposing and developing said negative chemically amplified photosensitive material to form a pattern;

removing a part of said amorphous ITO film which is not covered with said pattern;

removing said pattern; and

heating said amorphous ITO film to microcrystallize said amorphous ITO film.

15. The process according to claim 14, said process further comprising a step of inspecting said substrate after the development under a light which includes a spectrum having a wavelength of approximately 380 nm or less.

16. The process according to claim 14, characterized in that said substrate has a metal feature provided thereon.

17. The process according to claim 14, wherein the step of removing the amorphous ITO film includes a step of brining the part of the amorphous ITO film which is not covered with the pattern into contact with acid selected from the group consisting from oxalic acid, phosphoric acid and sulfuric acid.

18. The process according to claim 14, wherein the negative chemically amplified photosensitive material comprises phenolic novolak, methylol melamine and a photo-acid generator.

19. The process according to claim 18, wherein the photo-acid generator is triazines.