| 摘要 |
PROBLEM TO BE SOLVED: To provide a transistor having favorable electrical characteristics; or provide a transistor having stable electrical characteristics; or provide a transistor having less current in an off-state; or provide a semiconductor device having the transistor.SOLUTION: A semiconductor device has a first conductor, a second conductor, a third conductor, an oxide semiconductor and an insulator. The oxide semiconductor has a first region, a second region and a third region. In the first region, the oxide semiconductor overlaps with the first conductor via the insulator. In the second region, the oxide semiconductor contacts the second conductor. In the third region, the oxide semiconductor contacts the third conductor. The oxide semiconductor has a fourth region having a single crystal structure and the fourth region has the first region. |
