| 摘要 |
A method for manufacturing a highly reliable semiconductor device with less change in threshold voltage is provided. An insulating film from which oxygen can be released by heating is formed in contact with an oxide semiconductor layer, and light irradiation treatment is performed on a gate electrode or a metal layer formed in a region which overlaps with the gate electrode, so that oxygen is added into the oxide semiconductor layer in a region which overlaps with the gate electrode. Accordingly, oxygen vacancies or interface states in the oxide semiconductor layer in a region which overlaps with the gate electrode can be reduced. |
