| 摘要 |
The present invention provides a semiconductor device reducing defects in an oxide semiconductor film. In addition, the present invention provides a semiconductor device using an oxide semiconductor film improving the electrical characteristics or the reliability. The semiconductor device includes a transistor including a gate electrode on a substrate; a gate insulating film covering the gate electrode; a multi-layer film overlapping with the gate electrode through the gate insulating film; and a pair of electrodes in contact with the multi-layer film; and an oxide insulating film covering the transistor, wherein the multi-layer film includes an oxide semiconductor film and an oxide film containing In or Ga; the oxide insulating film contains more oxygen than that in the stoichiometric composition; and in the transistor, by a bias-temperature stress test, threshold voltage does not change or the amount of the change in a positive direction or a negative direction is less than or equal to 1.0 V, preferably less than or equal to 0.5 V. |
