Method for manufacturing oxide semiconductor film
A method comprising a step of forming an oxide semiconductor film over a substrate by a sputtering method while heating the substrate at a temperature of higher than 200° C. and lower than or equal to 400° C. is provided. The oxide semiconductor film comprises a crystalline region and is in a non-single-crystal state. The step of forming the oxide semiconductor film is performed by using a sputtering target comprising indium, gallium, zinc and oxygen and a sputtering gas comprising at least one of a rare gas and oxygen.
1. A method for manufacturing an oxide semiconductor film comprising a step of:
forming an oxide semiconductor film over a substrate by a sputtering method while heating the substrate at a temperature of higher than 200° C. and lower than or equal to 400° C.,
wherein the oxide semiconductor film comprises a crystalline region in which a c-axis is substantially perpendicular to a surface of the oxide semiconductor film,
wherein the oxide semiconductor film is in a non-single-crystal state,
wherein the step of forming the oxide semiconductor film is performed by using a sputtering target comprising indium, gallium, zinc and oxygen, and
wherein the step of forming the oxide semiconductor film is performed by using a sputtering gas comprising at least one of a rare gas and oxygen.
2. The method for manufacturing an oxide semiconductor film according to claim 1 ,
wherein the step of forming the oxide semiconductor film is performed in a treatment chamber, and
wherein a pressure of the treatment chamber is set to lower than or equal to 0.4 Pa.
3. The method for manufacturing an oxide semiconductor film according to claim 1 ,
wherein the step of forming the oxide semiconductor film is performed in a treatment chamber, and
wherein a leakage rate of the treatment chamber is set to lower than or equal to 1×10 −10 Pa·m 3 sec.
4. The method for manufacturing an oxide semiconductor film according to claim 1 , wherein the temperature at the step of forming the oxide semiconductor film is higher than or equal to 250° C. and lower than or equal to 350° C.
5. The method for manufacturing an oxide semiconductor film according to claim 1 , wherein a purity of the sputtering target is set to higher than or equal to 99.99%.
6. The method for manufacturing an oxide semiconductor film according to claim 1 , wherein a concentration of lithium in the oxide semiconductor film is 5×10 15 atoms/cm 3 or lower.
7. The method for manufacturing an oxide semiconductor film according to claim 1 , wherein a concentration of sodium in the oxide semiconductor film is 5×10 16 atoms/cm 3 or lower.
8. The method for manufacturing an oxide semiconductor film according to claim 1 , wherein a concentration of potassium in the oxide semiconductor film is 5×10 15 atoms/cm 3 or lower.
9. The method for manufacturing an oxide semiconductor film according to claim 1 , wherein an angle between the c-axis and a normal of the surface of the oxide semiconductor film is greater than or equal to 0° and less than or equal to 20°.
10. A method for manufacturing an oxide semiconductor film comprising a step of:
forming an oxide semiconductor film over a substrate by a sputtering method while heating the substrate at a temperature of higher than 200° C. and lower than or equal to 400° C.; and
performing a heat treatment after forming the oxide semiconductor film at a temperature higher than the temperature at the step of forming the oxide semiconductor film,
wherein the oxide semiconductor film comprises a crystalline region in which a c-axis is substantially perpendicular to a surface of the oxide semiconductor film,
wherein the oxide semiconductor film is in a non-single-crystal state,
wherein the step of forming the oxide semiconductor film is performed by using a sputtering target comprising indium, gallium, zinc and oxygen, and
wherein the step of forming the oxide semiconductor film is performed by using a sputtering gas comprising at least one of a rare gas and oxygen.
11. The method for manufacturing an oxide semiconductor film according to claim 10 ,
wherein the step of forming the oxide semiconductor film is performed in a treatment chamber, and
wherein a pressure of the treatment chamber is set to lower than or equal to 0.4 Pa.
12. The method for manufacturing an oxide semiconductor film according to claim 10 ,
wherein the step of forming the oxide semiconductor film is performed in a treatment chamber, and
wherein a leakage rate of the treatment chamber is set to lower than or equal to 1×10 −10 Pa·m 3 sec.
13. The method for manufacturing an oxide semiconductor film according to claim 10 , wherein the temperature at the step of forming the oxide semiconductor film is higher than or equal to 250° C. and lower than or equal to 350° C.
14. The method for manufacturing an oxide semiconductor film according to claim 10 , wherein a purity of the sputtering target is set to higher than or equal to 99.99%.
15. The method for manufacturing an oxide semiconductor film according to claim 10 , wherein a concentration of lithium in the oxide semiconductor film is 5×10 15 atoms/cm 3 or lower.
16. The method for manufacturing an oxide semiconductor film according to claim 10 , wherein a concentration of sodium in the oxide semiconductor film is 5×10 16 atoms/cm 3 or lower.
17. The method for manufacturing an oxide semiconductor film according to claim 10 , wherein a concentration of potassium in the oxide semiconductor film is 5×10 15 atoms/cm 3 or lower.
18. The method for manufacturing an oxide semiconductor film according to claim 10 , wherein an angle between the c-axis and a normal of the surface of the oxide semiconductor film is greater than or equal to 0° and less than or equal to 20°.