Oxide semiconductor film and semiconductor device

Patent metadata

Field	Value
Publication number	US-9478668-B2
Application number	US-201213438206-A
Country	US
Kind code	B2
Filing date	Apr 3, 2012
Priority date	Apr 13, 2011
Publication date	Oct 25, 2016
Grant date	Oct 25, 2016

Abstract

To provide an oxide semiconductor film having stable electric conductivity and a highly reliable semiconductor device having stable electric characteristics by using the oxide semiconductor film. The oxide semiconductor film contains indium (In), gallium (Ga), and zinc (Zn) and includes a c-axis-aligned crystalline region aligned in the direction parallel to a normal vector of a surface where the oxide semiconductor film is formed. Further, the composition of the c-axis-aligned crystalline region is represented by In 1+δ Ga 1-δ O 3 (ZnO) m (0<δ<1 and m=1 to 3 are satisfied), and the composition of the entire oxide semiconductor film including the c-axis-aligned crystalline region is represented by In x Ga y O 3 (ZnO) m (0<x<2, 0<y<2, and m=1 to 3 are satisfied).

First claim

What is claimed is:

1. An oxide semiconductor film comprising a crystalline region,
wherein the crystalline region comprises a crystal,
wherein a c-axis of the crystal is oriented substantially in a direction parallel to a normal vector of a surface where the oxide semiconductor film is formed,
wherein a composition of the crystalline region is represented by In 1+δ Ga 1-δ O 3 (ZnO) m (0<δ<1 and m=1 to 3 are satisfied),
wherein a composition of the oxide semiconductor film is represented by In x Ga y O 3 (ZnO) m (0<x<2, 0<y<2, and m=1 to 3 are satisfied), and
wherein the composition of the crystalline region is different from the composition of the entire oxide semiconductor film.

2. The oxide semiconductor film according to claim 1 , wherein a total concentration of phosphorus, boron, and nitrogen contained in the oxide semiconductor film is lower than or equal to 5×10 19 atoms/cm 3 .

3. The oxide semiconductor film according to claim 1 , wherein a total concentration of phosphorus, boron, and nitrogen contained in the oxide semiconductor film is lower than or equal to 5×10 18 atoms/cm 3 .

4. The oxide semiconductor film according to claim 1 , wherein a concentration of any one of phosphorus, boron, and nitrogen contained in the oxide semiconductor film is lower than or equal to 1×10 19 atoms/cm 3 .

5. The oxide semiconductor film according to claim 1 , wherein concentrations of lithium and potassium contained in the oxide semiconductor film are lower than or equal to 5×10 15 atoms/cm 3 .

6. The oxide semiconductor film according to claim 1 , wherein a concentration of sodium contained in the oxide semiconductor film is lower than or equal to 5×10 16 atoms/cm 3 .

7. A semiconductor device comprising:
a gate electrode;
an oxide semiconductor film;
a first insulating film between the gate electrode and the oxide semiconductor film; and
a second insulating film over the oxide semiconductor film,
wherein the oxide semiconductor film comprises a crystalline region,
wherein the crystalline region comprises a crystal,
wherein a c-axis of the crystal is oriented substantially in a direction parallel to a normal vector of a surface of the first insulating film,
wherein a composition of the crystalline region is represented by In 1+δ Ga 1-δ O 3 (ZnO) m (0<δ<1 and m=1 to 3 are satisfied),
wherein a composition of the oxide semiconductor film is represented by In x Ga y O 3 (ZnO) m (0<x<2, 0<y<2, and m=1 to 3 are satisfied), and
wherein the composition of the crystalline region is different from the composition of the entire oxide semiconductor film.

8. The semiconductor device according to claim 7 , wherein a total concentration of boron, phosphorus, and nitrogen contained in the oxide semiconductor film is lower than or equal to 5×10 19 atoms/cm 3 .

9. The semiconductor device according to claim 7 , wherein a total concentration of boron, phosphorus, and nitrogen contained in the oxide semiconductor film is lower than or equal to 5×10 18 atoms/cm 3 .

10. The semiconductor device according to claim 7 , wherein a concentration of any one of boron, phosphorus, and nitrogen contained in the oxide semiconductor film is lower than or equal to 1×10 19 atoms/cm 3 .

11. The semiconductor device according to claim 7 , wherein concentrations of lithium and potassium contained in the oxide semiconductor film are lower than or equal to 5×10 15 atoms/cm 3 .

12. The semiconductor device according to claim 7 , wherein a concentration of sodium contained in the oxide semiconductor film is lower than or equal to 5×10 16 atoms/cm 3 .

13. A semiconductor device comprising:
a first insulating film;
an oxide semiconductor film over the first insulating film;
a second insulating film over the oxide semiconductor film; and
a gate electrode over the second insulating film,
wherein the oxide semiconductor film comprises a crystalline region,
wherein the crystalline region comprises a crystal,
wherein a c-axis of the crystal is oriented substantially in a direction parallel to a normal vector of a surface of the first insulating film,
wherein a composition of the crystalline region is represented by In 1+δ Ga 1-δ O 3 (ZnO) m (0<δ<1 and m=1 to 3 are satisfied),
wherein a composition of the oxide semiconductor film is represented by In x Ga y O 3 (ZnO) m (0<x<2, 0<y<2, and m=1 to 3 are satisfied), and
wherein the composition of the crystalline region is different from the composition of the entire oxide semiconductor film.

14. The semiconductor device according to claim 13 , wherein a total concentration of boron, phosphorus, and nitrogen contained in the oxide semiconductor film is lower than or equal to 5×10 19 atoms/cm 3 .

15. The semiconductor device according to claim 13 , wherein a total concentration of boron, phosphorus, and nitrogen contained in the oxide semiconductor film is lower than or equal to 5×10 18 atoms/cm 3 .

16. The semiconductor device according to claim 13 , wherein a concentration of any one of boron, phosphorus, and nitrogen contained in the oxide semiconductor film is lower than or equal to 1×10 19 atoms/cm 3 .

17. The semiconductor device according to claim 13 , wherein concentrations of lithium and potassium contained in the oxide semiconductor film are lower than or equal to 5×10 15 atoms/cm 3 .

18. The semiconductor device according to claim 13 , wherein a concentration of sodium contained in the oxide semiconductor film is lower than or equal to 5×10 16 atoms/cm 3 .

19. The semiconductor device according to claim 13 , wherein the first insulating film comprises a surface whose average surface roughness is less than 0.5 nm.

Assignees

• Takahashi Masahiro
• Akimoto Kengo
• Yamazaki Shunpei
• Semiconductor Energy Lab

Inventors

• Takahashi Masahiro
• Akimoto Kengo
• Yamazaki Shunpei

Classifications

• H10P14/3466

  Crystal orientation · CPC title

• H10P14/3434

  being oxide semiconductor materials (Group IIB-VIA semiconductor materials H10P14/3424) · CPC title

• C01G15/006

  Compounds containing gallium, indium or thallium, with or without oxygen or hydrogen, and containing two or more other elements · CPC title

• G02F1/1368

  in which the switching element is a three-electrode device {(G02F1/136277 takes precedence)} · CPC title

• G02F2201/123

  pixel · CPC title