SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a semiconductor device which can achieve microfabrication and high integration; provide good electrical characteristics to a semiconductor device using an oxide semiconductor; or provide a semiconductor device which inhibits variation in electrical characteristics of the semiconductor device using an oxide semiconductor and which has high reliability.SOLUTION: A semiconductor device comprises: an island-like oxide semiconductor layer provided on an insulating surface; an insulation layer which surrounds lateral faces of the oxide semiconductor layer; a source electrode layer and a drain electrode layer which have contact with a top face of the oxide semiconductor layer and a top face of the insulation layer; a gate electrode layer provided on the oxide semiconductor layer in an overlapping manner; and a gate insulation layer provided between the oxide semiconductor layer and the gate electrode layer. The source electrode layer and the drain electrode layer are provided on an upper side of the top face of the oxide semiconductor layer. The top face of the insulation layer is treated with planarization.