METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To reduce oxygen vacancies existing in an oxide semiconductor film and in the vicinity of the oxide semiconductor film and to improve electric characteristics of a transistor using the oxide semiconductor film.SOLUTION: A semiconductor device includes a gate electrode whose Gibbs free energy for oxidation reaction is higher than that of a gate insulating film. In a region where the gate electrode is in contact with the gate insulating film, oxygen moves from the gate electrode to the gate insulating film because the gate electrode has higher Gibbs free energy for oxidation reaction than that of the gate insulating film. The oxygen passes through the gate insulating film and is supplied to the oxide semiconductor film disposed in contact with the gate insulating film, thereby realizing reduction of oxygen vacancies in the oxide semiconductor film and in the vicinity of the oxide semiconductor film.SELECTED DRAWING: Figure 1