METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a semiconductor device including an oxide semiconductor which is capable of having stable electric characteristics and achieving high reliability.SOLUTION: By applying dehydration or dehydrogenation treatment to a base insulating layer provided in contact with an oxide semiconductor layer, the water and hydrogen contents of the base insulating layer are decreased. By subsequently applying oxygen doping treatment, oxygen which can be eliminated together with water and hydrogen is supplied to the base insulating layer. By formation of the oxide semiconductor layer in contact with the base insulating layer whose water and hydrogen contents are decreased and whose oxygen content is increased, oxygen can be supplied to the oxide semiconductor layer while entry of water and hydrogen into the oxide semiconductor layer is suppressed.