Method of manufacturing semiconductor device

• US 5,624,861 A
• Filed: 07/23/1996
• Issued: 04/29/1997
• Est. Priority Date: 08/28/1995
• Status: Expired due to Term

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Shibuya, Tsukasa
• Primary Examiner(s): TRINH, MICHAEL MANH
• Application Number:
  US08/681,512
• Time in Patent Office: 280 Days
• Field of Search: 437/40 TFT, 437/41 TFT, 437/913, 437/235, 437/236, 437/233, 437/40 TOI, 437/41 TFI, 148/DIG. 150, 148/DIG. 102, 148/DIG. 106, 148/DIG. 1
• US Class Current: 438/164
• CPC Class Codes: H01L 27/1214 comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
• CPC Class Codes: H01L 27/1262 with a particular formation, treatment or coating of the substrate
• CPC Class Codes: H01L 27/1274 using crystallisation of amorphous semiconductor or recrystallisation of crystalline semiconductor
• CPC Class Codes: Y10S 438/911 Differential oxidation and etching

Abstract

A manufacturing method of a semiconductor device includes the steps of depositing a metallic film (light-shielding film), an insulating film and a semiconductor film in this order on an insulating substrate, and after patterning the insulating film and the semiconductor film in a predetermined shape, oxidizing an exposed region of the metallic film using the insulating film and the semiconductor film as a mask. As a result, the light-shielding film composed of the metallic film is formed so as to cover the semiconductor film to block light from an external portion. The manufacturing method permits a process of forming a resist pattern for use in forming the light-shielding film and a process of etching the light-shielding film to be omitted, thereby reducing the required number of processes. Moreover, as a level difference is not generated around the light-shielding film, a generation of a level difference on the semiconductor film can be prevented. Furthermore, as the light-shielding film can be formed completely overlapped with the semiconductor film, a reduction in a display region of the semiconductor device can be avoided, thereby improving an aperture ratio.

Claims

1. A method of manufacturing a semiconductor device provided with a thin film transistor including a light-shielding film composed of a metallic film formed on an insulating substrate and a semiconductor film formed on the light-shielding film via an insulating film, and a pixel electrode connected to said thin film transistor, comprising the steps of:

depositing said metallic film, said insulating film and said semiconductor film in this order on said insulating substrate;

patterning said insulating film and said semiconductor film thus deposited into a predetermined shape; and

forming a metallic oxide film by oxidizing an exposed region of said metallic film using the patterned insulating film and the semiconductor film as a mask.

2. The method of manufacturing a semiconductor device as set forth in claim 1, wherein:

said metallic film is made of at least one high melting-point metal selected from the group consisting of Ta, Ti, Mo and W.

3. The method of manufacturing a semiconductor device as set forth in claim 1, wherein:

said metallic film is composed of a metal which shows such a property that light is transmissible therethrough when oxidized.

4. The method of manufacturing a semiconductor device as set forth in claim 1, wherein:

said metallic film is composed of a metal which shows an insulating property when oxidized.

5. The method of manufacturing a semiconductor device as set forth in claim 1, wherein:

said step of patterning said semiconductor film and said insulating film is performed by a dry etching method.

6. The method of manufacturing a semiconductor device as set forth in claim 1, wherein:

said process of oxidizing the exposed region of said metallic film is performed by an anodic oxidization method.

7. The method of manufacturing a semiconductor device as set forth in claim 1, wherein:

said process of oxidizing the exposed region of said metallic film is performed by an annealing method in an atmosphere of oxygen.

8. The method of manufacturing a semiconductor device as set forth in claim 1, wherein:

said deposited semiconductor film is an amorphous silicon film.

9. The method of manufacturing a semiconductor device as set forth in claim 8, further comprising the step of:

forming a polysilicon film by crystallizing said amorphous silicon film.

10. The method of manufacturing a semiconductor device as set forth in claim 1, wherein:

said deposited semiconductor film is a polysilicon film.

11. A method of manufacturing a semiconductor device provided with a thin film transistor including a light-shielding film composed of a metallic film formed on an insulating substrate and a semiconductor film formed on the light-shielding film via an insulating film, and a pixel electrode connected to said thin film transistor, comprising the steps of:

depositing said metallic film on said insulating substrate;

forming a first metallic oxide film by oxidizing a surface layer of said metallic film only to a predetermined thickness;

depositing said semiconductor film on said first metallic oxide film formed by the oxidizing process;

patterning said first metallic oxide film and said semiconductor film in a predetermined shape; and

forming a second metallic oxide film by oxidizing an exposed region of said metallic film using the patterned first metallic oxide film and said semiconductor film as a mask.

12. The method of manufacturing a semiconductor device as set forth in claim 11, wherein:

said metallic film is made of at least one high melting-point metal selected from the group consisting of Ta, Ti, Mo and W.

13. The method of manufacturing a semiconductor device as set forth in claim 11, wherein:

said metallic film is composed of a metal which shows such a property that light is transmissible therethrough when oxidized.

14. The method of manufacturing a semiconductor device as set forth in claim 11, wherein:

said metallic film is composed of a metal which shows an insulating property when oxidized.

15. The method of manufacturing a semiconductor device as set forth in claim 11, wherein:

said step of patterning said semiconductor film and said insulating film is performed by a dry etching method.

16. The method of manufacturing a semiconductor device as set forth in claim 11, wherein:

said process of oxidizing the exposed region of said metallic film is performed by an anodic oxidization method.

17. The method of manufacturing a semiconductor device as set forth in claim 11, wherein:

said process of oxidizing the exposed region of said metallic film is performed by an annealing method in an atmosphere of oxygen.

18. The method of manufacturing a semiconductor device as set forth in claim 11, wherein:

said deposited semiconductor film is an amorphous silicon film.

19. The method of manufacturing a semiconductor device as set forth in claim 18, further comprising the step of:

forming a polysilicon film by crystallizing said amorphous silicon film.

20. The method of manufacturing a semiconductor device as set forth in claim 11, wherein:

said deposited semiconductor film is a polysilicon film.