MANUFACTURING FOR SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a manufacturing method for a semiconductor device having a semiconductor layer with high field-effect mobility. SOLUTION: In a manufacturing method, a polysilicon film 3 is formed on a transparent insulating substrate 1, and the surface of the polysilicon film 4 is oxidized to form a thick silicon dioxide film 4. After the silicon dioxide film 4 is removed, the uneven surface of the polysilicon film 3 is polished and flattened by a CMP(chemical-mechanical polishing) method, and the surface of the polysilicon film 3 is oxidized again to form a thin silicon dioxide film 4a. After that, the silicon dioxide film 4a is removed. Then, the polysilicon film 3 obtained has a flat face and extremely satisfactory characteristics in crystallinity. As a result, field-effect mobility in a TFT(thin-film transistor) with the polysilicon film 3 as an active layer can be made to improve.