MANUFACTURING METHOD OF SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a semiconductor device using an oxide semiconductor having stable electric characteristics.SOLUTION: By a halogen element typified by fluorine or chlorine, impurities such as hydrogen and moisture (hydrogen atoms, or a chemical compound containing hydrogen atoms such as HO) contained in an oxide semiconductor layer are removed from the oxide semiconductor layer, and concentration of the impurities in the oxide semiconductor layer is reduced. The halogen element can be included in a gate insulating layer and/or an insulating layer provided in contact with the oxide semiconductor layer to form the gate insulating layer and/or the insulating layer, or the halogen element may be attached to the oxide semiconductor layer by plasma treatment under a gas atmosphere containing the halogen element.