METHOD OF MANUFACTURING SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To manufacture and provide a highly reliable semiconductor device provided with thin film transistors having stable electric characteristics.SOLUTION: A method of manufacturing a semiconductor device provided with thin film transistors each employing an oxide semiconductor film as a semiconductor layer containing a channel formation region includes: carrying out a heat treatment for dehydration or dehydrogenation that enhances purity of the oxide semiconductor film and reduces impurities such as moisture; reducing impurities such as moisture contained not only in the oxide semiconductor film but in a gate insulation layer; and reducing impurities such as moisture contained at an interface between a film and the oxide semiconductor film provided vertically in contact with each other.