Method for manufacturing semiconductor device

A method for manufacturing a semiconductor device, comprising:

• forming an oxide semiconductor comprising indium, gallium, and zinc;
• forming a first insulator over the oxide semiconductor;
• forming a first conductor over the first insulator, wherein the first conductor overlaps with the oxide semiconductor;
• after forming the first conductor, forming an oxygen vacancy site in a first position of the oxide semiconductor, wherein the first position does not overlap with the first conductor;
• and
• supplying hydrogen into the oxygen vacancy site in the first position of the oxide semiconductor.

A method for manufacturing a semiconductor device, comprising:

• forming an oxide semiconductor comprising indium, gallium, and zinc;
• forming a first insulator over the oxide semiconductor;
• forming a first conductor over the first insulator, wherein the first conductor overlaps with the oxide semiconductor;
• after forming the first conductor, forming an oxygen vacancy site in a first position of the oxide semiconductor, wherein the first position does not overlap with the first conductor;
• and
• after forming the oxygen vacancy site, forming a donor level in the first position.

A method for manufacturing a semiconductor device, comprising:

• forming an oxide semiconductor comprising indium, gallium, and zinc;
• forming a first insulator over the oxide semiconductor;
• forming a first conductor over the first insulator, wherein the first conductor overlaps with the oxide semiconductor;
• after forming the first conductor, implanting an ion into a first position of the oxide semiconductor from the first conductor side, wherein the first position does not overlap with the first conductor;
• and
• after performing the ion, performing a heat treatment on the oxide semiconductor.