Oxide semiconductor film and semiconductor device
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).
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.