SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To impart stable electrical characteristics to a transistor using an oxide semiconductor film, to impart excellent electrical characteristics to a transistor using an oxide semiconductor film, and to provide a highly reliable semiconductor device having the transistor.SOLUTION: The transistor has: a multilayer film in which an oxide semiconductor film and an oxide film are laminated; a gate electrode; and a gate insulating film. The multilayer film is provided to overlap the gate electrode via the gate insulating film. The multilayer film has a shape having a first angle formed by a lower surface of the oxide semiconductor film and a side surface of the oxide semiconductor film, and a second angle formed by a lower surface of the oxide film and a side surface of the oxide film. The first angle is smaller than the second angle and is an acute angle. The semiconductor device is manufactured by using the transistor.