Oxide semiconductor film and semiconductor device

• US 8,686,416 B2
• Filed: 03/15/2012
• Issued: 04/01/2014
• Est. Priority Date: 03/25/2011
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Honda, Tatsuya, Akimoto, Kengo, Kanemura, Hiroshi, Hiraishi, Suzunosuke
• Primary Examiner(s): Maldonado, Julio J
• Assistant Examiner(s): SHOOK, DANIEL P
• Application Number:
  US13/421,038
• Publication Number:
  US 20120241735A1
• Time in Patent Office: 747 Days
• Field of Search: 257/43, 257/E29.296, 257/E21.461, 438/104
• US Class Current: 257/43
• 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 29/247 Amorphous materials
• CPC Class Codes: H01L 29/66969 of devices having semiconductor bodies not comprising group 14 or group 13/15 materials comprising selenium or tellurium in uncombined form other than as impurities in semiconductor bodies of other materials, comprising cuprous oxide or cuprous iodide H01L21/02365
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate
• CPC Class Codes: H01L 29/78693 the semiconducting oxide being amorphous

Abstract

Provided is an oxide semiconductor film which has more stable electric characteristics and essentially consists of indium zinc oxide. In addition, provided is a highly reliable semiconductor device which has stable electric characteristics by using the oxide semiconductor film. The oxide semiconductor film essentially consisting of indium zinc oxide has a hexagonal crystal structure in which the a-b plane is substantially parallel to a surface of the oxide semiconductor film and a rhombohedral crystal structure in which the a-b plane is substantially parallel to the surface of the oxide semiconductor film.

Claims

1. An oxide semiconductor film essentially consisting of indium zinc oxide, the oxide semiconductor film comprising:

a hexagonal crystal structure in which an a-b plane is substantially parallel to a surface of the oxide semiconductor film; and

a rhombohedral crystal structure in which an a-b plane is substantially parallel to the surface of the oxide semiconductor film.

2. The oxide semiconductor film according to claim 1,

wherein the oxide semiconductor film comprises a plurality of regions each of which comprises the hexagonal crystal structure and the rhombohedral crystal structure.

3. An oxide semiconductor film essentially consisting of indium zinc oxide, the oxide semiconductor film comprising:

a hexagonal crystal structure in which an a-b plane is substantially parallel to a surface of the oxide semiconductor film; and

a rhombohedral crystal structure in which an a-b plane is substantially parallel to the surface of the oxide semiconductor film,

wherein the hexagonal crystal structure is a crystal structure of an oxide semiconductor having a composition ratio of In;

Zn=1;

1, and

wherein the rhombohedral crystal structure is a crystal structure of an oxide semiconductor having a composition ratio of In;

Zn=2;

1.

4. The oxide semiconductor film according to claim 3,

wherein the oxide semiconductor film comprises a plurality of regions each of which comprises the hexagonal crystal structure and the rhombohedral crystal structure.

5. A semiconductor device comprising:

a gate electrode;

an oxide semiconductor film essentially consisting of indium zinc oxide;

a first insulating film provided between the gate electrode and the oxide semiconductor film;

a source electrode and a drain electrode provided in contact with the oxide semiconductor film; and

a second insulating film provided over the oxide semiconductor film,

wherein the oxide semiconductor film includes a hexagonal crystal structure in which an a-b plane is substantially parallel to a surface of the oxide semiconductor film and a rhombohedral crystal structure in which an a-b plane is substantially parallel to the surface of the oxide semiconductor film.

6. The semiconductor device according to claim 5,

wherein the oxide semiconductor film comprises a plurality of regions each of which comprises the hexagonal crystal structure and the rhombohedral crystal structure.

7. A semiconductor device comprising:

a gate electrode;

an oxide semiconductor film essentially consisting of indium zinc oxide;

a first insulating film provided between the gate electrode and the oxide semiconductor film;

a source electrode and a drain electrode provided in contact with the oxide semiconductor film; and

a second insulating film provided over the oxide semiconductor film,

wherein the oxide semiconductor film includes a hexagonal crystal structure in which an a-b plane is substantially parallel to a surface of the oxide semiconductor film and a rhombohedral crystal structure in which an a-b plane is substantially parallel to the surface of the oxide semiconductor film,

wherein the hexagonal crystal structure is a crystal structure of an oxide semiconductor having a composition ratio of In;

Zn=1;

1, and

wherein the rhombohedral crystal structure is a crystal structure of an oxide semiconductor having a composition ratio of In;

Zn=2;

1.

8. The semiconductor device according to claim 7,

wherein the oxide semiconductor film comprises a plurality of regions each of which comprises the hexagonal crystal structure and the rhombohedral crystal structure.