SEMICONDUCTOR DEVICE, AND MANUFACTURING METHOD OF OXIDE SEMICONDUCTOR LAYER

摘要

PROBLEM TO BE SOLVED: To reduce variations in threshold voltage to stabilize electric characteristics of a thin-film transistor including an oxide semiconductor layer, and to reduce an off current.SOLUTION: In a thin-film transistor including an oxide semiconductor layer, an oxide semiconductor layer containing an insulating oxide is laminated on an oxide semiconductor layer and a thin-film transistor is formed so that the oxide semiconductor layer and a source electrode layer or a drain electrode layer are in contact with each other via the oxide semiconductor layer containing the insulating oxide. With this method, the variations in threshold voltage of the thin-film transistor can be reduced and electric characteristics can be stabilized. In addition, an off current can be reduced.