MANUFACTURING METHOD OF SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a semiconductor device with stable electric characteristics, in which an oxide semiconductor is used.SOLUTION: Impurity concentration in an oxide semiconductor layer is reduced in such a way that a silicon oxide layer including many defects represented by dangling bonds is formed in contact with the oxide semiconductor layer, and an impurity such as hydrogen or moisture (a hydrogen atom or a compound including a hydrogen atom such as HO) included in the oxide semiconductor layer is diffused into the silicon oxide layer. Further, a mixed region is provided on an interface between the oxide semiconductor layer and the silicon oxide layer.