Oxide semiconductor film and semiconductor device

• US 10,439,068 B2
• Filed: 01/29/2016
• Issued: 10/08/2019
• Est. Priority Date: 02/12/2015
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Shimomura, Akihisa, Koezuka, Junichi, Okazaki, Kenichi, Yamane, Yasumasa, Sato, Yuhei, Yamazaki, Shunpei
• Primary Examiner(s): Ahmadi, Mohsen
• Application Number:
  US15/010,045
• Publication Number:
  US 20160240682A1
• Time in Patent Office: 1,348 Days
• CPC Class Codes: C23C 14/08 Oxides C23C14/10 takes precedence
• CPC Class Codes: C23C 14/34 Sputtering
• CPC Class Codes: H01L 21/02 Manufacture or treatment of semiconductor devices or of parts thereof
• CPC Class Codes: H01L 27/1225 with semiconductor materials not belonging to the group IV of the periodic table, e.g. InGaZnO
• CPC Class Codes: H01L 29/045 by their particular orientation of crystalline planes
• 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 29/786 Thin film transistors, i.e. transistors with a channel being at least partly a thin film transistors having only the source or the drain region on an insulator layer H01L29/0653; thin film FinFETs H01L29/785
• CPC Class Codes: H01L 29/78648 arranged on opposing sides of the channel
• 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 29/78696 characterised by the structure of the channel, e.g. multichannel, transverse or longitudinal shape, length or width, doping structure, or the overlap or alignment between the channel and the gate, the source or the drain, or the contacting structure of the channel H01L29/78612 takes precedence; transistors having a drain offset region or a lightly doped drain [LDD] H01L29/78621

Abstract

To provide a novel oxide semiconductor film. The oxide semiconductor film includes In, M, and Zn. The M is Al, Ga, Y, or Sn. In the case where the proportion of In in the oxide semiconductor film is 4, the proportion of M is greater than or equal to 1.5 and less than or equal to 2.5 and the proportion of Zn is greater than or equal to 2 and less than or equal to 4.

Claims

1. An oxide semiconductor film comprising In, M, and Zn,

wherein the oxide semiconductor film has a composition in a neighborhood of a solid solution range of an In_1+xM₁₋

xO₃(ZnO)_y structure,

wherein the M is Al, Ga, Y, or Sn,

wherein x satisfies 0<

x<

0.5,

wherein y is approximately 1,

wherein the oxide semiconductor film is formed with a sputtering apparatus,

wherein the sputtering apparatus comprises a polycrystalline metal oxide target,

wherein the polycrystalline metal oxide target has a composition in a neighborhood of In;

M;

Zn=4;

2;

4.1, and

wherein in the case where a proportion of the In of the polycrystalline metal oxide target is 4, a proportion of the M is greater than or equal to 1.5 and less than or equal to 2.5 and a proportion of the Zn is greater than or equal to 3.1 and less than or equal to 5.1.

2. The oxide semiconductor film according to claim 1,

wherein the oxide semiconductor film has an atomic ratio in a neighborhood of In:

M;

Zn=4;

2;

3, and

wherein in the case where a proportion of the In is 4, a proportion of the M is greater than or equal to 1.5 and less than or equal to 2.5 and a proportion of the Zn is greater than or equal to 2 and less than or equal to 4.

3. The oxide semiconductor film according to claim 1,

wherein the oxide semiconductor film comprises a crystal part, and

wherein the crystal part has c-axis alignment.

4. The oxide semiconductor film according to claim 1, wherein the oxide semiconductor film comprises a region with a hydrogen concentration of lower than 1×

10²⁰ atoms/cm³.

5. The oxide semiconductor film according to claim 1, wherein the oxide semiconductor film comprises a region where the In, the M, the Zn, and O atoms in total account for 99.97 atomic % or more.

6. The oxide semiconductor film according to claim 1, wherein the oxide semiconductor film comprises a region where Fe, Ni, and Si atoms in total account for lower than 0.03 atomic %.

7. A semiconductor device comprising the oxide semiconductor film according to claim 1.

8. An oxide semiconductor film comprising:

a first film; and

a second film over the first film,

wherein each of the first film and the second film comprises In, M, and Zn,

wherein the M is Al, Ga, Y, or Sn,

wherein the first film has a composition in a neighborhood of a solid solution range of an In_1+xM<sub>1−

x</sub>O₃(ZnO)_y structure,

wherein the second film comprises a region having a composition in a neighborhood of a solid solution range of an In_1+vM<sub>1−

v</sub>O₃(ZnO)_w structure and having a smaller proportion of indium atoms than the first film,

wherein x satisfies 0<

x<

0.5,

wherein y is approximately 1,

wherein v satisfies −

0.2≤

v<

0.2,

wherein w is approximately 1,

wherein the first film comprises a region where the In, the M, the Zn, and O atoms in total account for 99.97 atomic % or more,

wherein the first film and the second film are formed by a sputtering apparatus,

wherein the sputtering apparatus comprises a first polycrystalline metal oxide target and a second polycrystalline metal oxide target,

wherein the first polycrystalline metal oxide target has a composition in a neighborhood of In;

M;

Zn=4;

2;

4.1,

wherein the second polycrystalline metal oxide target has a composition in a neighborhood of In;

M;

Zn=1;

1;

1.2, and

wherein in the case where a proportion of the In of the first polycrystalline metal oxide target is 4, a proportion of the M is greater than or equal to 1.5 and less than or equal to 2.5 and a proportion of the Zn is greater than or equal to 3.1 and less than or equal to 5.1.

9. The oxide semiconductor film according to claim 8,

wherein x is approximately 0.33, and

wherein v is approximately 0.

10. The oxide semiconductor film according to claim 8,

wherein the first film has an atomic ratio in a neighborhood of In:

M;

Zn=4;

2;

3,

wherein the second film has an atomic ratio in a neighborhood of In;

M;

Zn=1;

1;

1, and

wherein in the case where a proportion of the In of the first film is 4, a proportion of the M is greater than or equal to 1.5 and less than or equal to 2.5 and a proportion of the Zn is greater than or equal to 2 and less than or equal to 4.

11. The oxide semiconductor film according to claim 8,

wherein the first film comprises a crystal part, and

wherein the crystal part has c-axis alignment.

12. The oxide semiconductor film according to claim 8, wherein the first film comprises a region with a hydrogen concentration of lower than 1×

10²⁰ atoms/cm³.

13. The oxide semiconductor film according to claim 8, wherein the first film comprises a region where Fe, Ni, and Si atoms in total account for lower than 0.03 atomic %.

14. A semiconductor device comprising the oxide semiconductor film according to claim 8.