| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor device using an oxide semiconductor with stable electric characteristics to improve reliability.SOLUTION: A transistor that includes an oxide semiconductor film is provided with: a metal oxide film constituted by a constituent(s) similar to that of the oxide semiconductor film is laminated on the lower surface of the oxide semiconductor film; and an insulating film constituted by a different constituent(s) from that of the metal oxide film and oxide semiconductor film is formed in contact with a surface of the metal oxide film facing the oxide semiconductor film. Further, the oxide semiconductor film used for an active layer of the transistor is a highly purified and electrically modified to i-type (intrinsic) by performing heat treatment to remove impurities such as hydrogen, moisture, a hydroxyl group or a hydride, and supplying oxygen which is a main component material constituting the oxide semiconductor and reduced together with the impurities in the impurity removal step. |
