SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME

• US 20120061663A1
• Filed: 09/07/2011
• Published: 03/15/2012
• Est. Priority Date: 09/13/2010
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: YAMAZAKI, Shunpei, NONAKA, Yusuke, INOUE, Takayuki, TSUBUKU, Masashi, AKIMOTO, Kengo, MIYANAGA, Akiharu
• Granted Patent: US 8,901,552 B2
• Time in Patent Office: Days
• US Class Current: 257/43
• CPC Class Codes: H01L 21/02488 Insulating materials
• CPC Class Codes: H01L 21/02554 Oxides
• CPC Class Codes: H01L 21/02565 Oxide semiconducting materials not being Group 12/16 materials, e.g. ternary compounds
• CPC Class Codes: H01L 29/04 characterised by their crystalline structure, e.g. polycrystalline, cubic or particular orientation of crystalline planes characterised by physical imperfections H01L29/30
• CPC Class Codes: H01L 29/24 including, apart from doping materials or other impurities, only semiconductor materials not provided for in groups H01L29/16, H01L29/18, H01L29/20, H01L29/22 including organic materials H10K99/00
• CPC Class Codes: H01L 29/78603 characterised by the insulating substrate or support H01L29/78657 takes precedence
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate

Abstract

An object is to provide a semiconductor device including an oxide semiconductor film, which has stable electrical characteristics and high reliability. A stack of first and second material films is formed by forming the first material film (a film having a hexagonal crystal structure) having a thickness of 1 nm to 10 nm over an insulating surface and forming the second material film having a hexagonal crystal structure (a crystalline oxide semiconductor film) using the first material film as a nucleus. As the first material film, a material film having a wurtzite crystal structure (e.g., gallium nitride or aluminum nitride) or a material film having a corundum crystal structure (α-Al₂O₃, α-Ga₂O₃, In₂O₃, Ti₂O₃, V₂O₃, Cr₂O₃, or α-Fe₂O₃) is used.

Claims

1. A method for manufacturing a semiconductor device, comprising the steps of:

forming a first material film having a hexagonal crystal structure over an insulating surface; and

forming a second material film having a hexagonal crystal structure on and in contact with the first material film,

wherein the second material film is thicker than the first material film, and

wherein the second material film is a crystalline oxide semiconductor film.

2. The method for manufacturing a semiconductor device according to claim 1, wherein the first material film is a material film having a wurtzite crystal structure or a corundum crystal structure.

3. The method for manufacturing a semiconductor device according to claim 1, wherein the first material film comprises gallium nitride or aluminum nitride.

4. The method for manufacturing a semiconductor device according to claim 1, wherein the first material film comprises α

-Al₂O₃, α

-Ga₂O₃, In₂O₃, Ti₂O₃, V₂O₃, Cr₂O₃, or α

-Fe₂O₃.

5. The method for manufacturing a semiconductor device according to claim 1, wherein the second material film comprises at least one of zinc, indium, and gallium.

6. A semiconductor device comprising:

a first material film having a hexagonal crystal structure over an insulating surface;

a second material film having a hexagonal crystal structure on and in contact with the first material film;

a gate insulating layer over the second material film; and

a gate electrode layer over the gate insulating layer,

wherein the second material film is thicker than the first material film, and

wherein the second material film is a crystalline oxide semiconductor film.

7. The semiconductor device according to claim 6, wherein the first material film comprises gallium oxide or aluminum oxide.

8. The semiconductor device according to claim 6, wherein the first material film comprises α

-Al₂O₃, α

-Ga₂O₃, In₂O₃, Ti₂O₃, V₂O₃, Cr₂O₃, or α

-Fe₂O₃.

9. The semiconductor device according to claim 6, wherein the second material film comprises zinc, indium, or gallium.

10. A semiconductor device comprising:

a gate electrode layer over an insulating surface;

a gate insulating layer over the gate electrode layer;

a first material film having a hexagonal crystal structure over the gate insulating layer; and

a second material film having a hexagonal crystal structure on and in contact with the first material film,

wherein the second material film is thicker than the first material film, and

wherein the second material film is a crystalline oxide semiconductor film.

11. The semiconductor device according to claim 10, wherein the first material film comprises gallium oxide or aluminum oxide.

12. The semiconductor device according to claim 10, wherein the first material film comprises α

-Al₂O₃, α

-Ga₂O₃, In₂O₃, Ti₂O₃, V₂O₃, Cr₂O₃, or α

-Fe₂O₃.

13. The semiconductor device according to claim 10, wherein the second material film comprises zinc, indium, or gallium.