Patent ID: 9711349
Date: 2017-07-18
CPC Classifications: H01L

Claim:
1. A semiconductor device comprising: a stacked-layer film as a base film comprising an oxide insulating film over a substrate and a metal oxide film over the oxide insulating film; a gate electrode over and in contact with the metal oxide film; a gate insulating film over the gate electrode; and an oxide semiconductor film over the gate insulating film, wherein the metal oxide film contains oxygen, wherein a thickness of the metal oxide film is greater than or equal to 3 nm and less than or equal to 15 nm, wherein the oxide insulating film contains oxygen in excess of a stoichiometric composition, wherein the stacked-layer film is configured to release oxygen by a heat treatment, wherein the metal oxide film comprises a first region in contact with the gate electrode and a second region in contact with the gate insulating film, and wherein a thickness of the first region is larger than a thickness of the second region.