Semiconductor device and method for manufacturing the same

• US 9,117,919 B2
• Filed: 05/15/2014
• Issued: 08/25/2015
• 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
• Primary Examiner(s): Blum, David S
• Application Number:
  US14/278,634
• Publication Number:
  US 20140246674A1
• Time in Patent Office: 467 Days
• Field of Search: 257/43, 257/59, 257/347, 257/E21.459, 257/E29.068
• US Class Current: 1/1
• 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 semiconductor device comprising:

a first material film comprising α

-Ga₂O₃, over a substrate;

an oxide semiconductor film comprising indium on the first material film;

a gate insulating layer adjacent to the oxide semiconductor film; and

a gate electrode layer adjacent to the oxide semiconductor film with the gate insulating layer therebetween;

wherein the oxide semiconductor film is thicker than the first material film.

2. The semiconductor device according to claim 1,

wherein the oxide semiconductor film has a hexagonal crystal structure.

3. The semiconductor device according to claim 1,

wherein the oxide semiconductor film further comprises tin and zinc.

4. The semiconductor device according to claim 1,

wherein the oxide semiconductor film further comprises zinc and gallium.

5. A semiconductor device comprising:

a first material film comprising α

-Ga₂O₃, over a substrate;

an oxide semiconductor film comprising indium on the first material film;

a gate insulating layer over the oxide semiconductor film; and

a gate electrode layer over the oxide semiconductor film with the gate insulating layer therebetween;

wherein the oxide semiconductor film is thicker than the first material film.

6. The semiconductor device according to claim 5, further comprising a source electrode layer and a drain electrode layer over the oxide semiconductor film,

wherein the gate insulating layer is formed over the source electrode layer and the drain electrode layer.

7. The semiconductor device according to claim 5,

wherein the oxide semiconductor film has a hexagonal crystal structure.

8. The semiconductor device according to claim 5,

wherein the oxide semiconductor film further comprises tin and zinc.

9. The semiconductor device according to claim 5,

wherein the oxide semiconductor film further comprises zinc and gallium.

10. A semiconductor device comprising:

a gate electrode;

a gate insulating film over the gate electrode;

a first material film comprising α

-Ga₂O₃, over the gate electrode with the gate insulating film interposed therebetween;

an oxide semiconductor film comprising indium on the first material film, wherein the oxide semiconductor film overlaps with the gate electrode; and

a source electrode layer and a drain electrode layer in electrical contact with the oxide semiconductor film,

wherein the oxide semiconductor film is thicker than the first material film.

11. The semiconductor device according to claim 10,

wherein the oxide semiconductor film is formed over the source electrode layer and the drain electrode layer.

12. The semiconductor device according to claim 10,

wherein the oxide semiconductor film has a hexagonal crystal structure.

13. The semiconductor device according to claim 10,

wherein the oxide semiconductor film further comprises tin and zinc.

14. The semiconductor device according to claim 10,

wherein the oxide semiconductor film further comprises zinc and gallium.