| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor device which has high reliability and exhibits stable electric characteristics; and manufacture a semiconductor device having high reliability.SOLUTION: In a semiconductor device manufacturing method, oxide semiconductor films are laminated in a manner such that a conduction band composes a well structure. A semiconductor device includes a second oxide semiconductor film which has a crystalline structure and arranged on a first oxide semiconductor film, and a third oxide semiconductor film on the second oxide semiconductor film. Compared with a conduction band of the first oxide semiconductor film and a conduction band of the third oxide semiconductor film, a conduction band of the second oxide semiconductor film exists deepest from the vacuum level. |
