| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor device including a transistor which materializes a so-called normally-off switching element, by setting a positive threshold voltage of a transistor where an oxide semiconductor is used in a channel formation region, and to achieve high reliability by imparting stabilized electrical characteristics in a semiconductor device having a transistor where an oxide semiconductor film is used in the channel formation region.SOLUTION: The semiconductor device includes a transistor where an oxide semiconductor film including a channel formation region, a source electrode layer and a drain electrode layer, a gate insulation film, and a gate electrode layer are laminated sequentially on an oxide insulation film. A conductive layer overlapping the gate electrode layer via the channel formation region and controlling the electrical characteristics of the transistor is provided in the oxide insulation film including an oxygen excess region. |
