| abstract |
A semiconductor device including a transistor that realizes a so-called normally-off switching element with a positive threshold voltage of a transistor in which an oxide semiconductor is used for a channel formation region is provided. In a semiconductor device including a transistor in which an oxide semiconductor film is used for a channel formation region, stable electrical characteristics are imparted and high reliability is achieved. A semiconductor device including a transistor in which an oxide semiconductor film including a channel formation region, a source electrode layer and a drain electrode layer, a gate insulating film, and a gate electrode layer are sequentially stacked over the oxide insulating film. In FIG. 2, a conductive layer that overlaps with the gate electrode layer through the channel formation region and controls the electrical characteristics of the transistor is provided in the oxide insulating film including the oxygen-excess region. [Selection] Figure 1 |