Patent ID: 9583601
Date: 2017-02-28
CPC Classifications: H01L

Claim:
1. A method for manufacturing a semiconductor device comprising the steps of: forming a gate insulating film over a gate electrode; forming an oxide semiconductor layer over the gate insulating film; forming an oxide layer over the oxide semiconductor layer to form a stacked-layer oxide film comprising the oxide semiconductor layer and the oxide layer; processing the stacked-layer oxide film into a predetermined shape; forming a conductive film including Ti over and in contact with the stacked-layer oxide film; etching the conductive film to form source and drain electrodes, and a depression portion in the oxide layer between the source and drain electrodes; and performing a heat treatment to form a region in the oxide layer having a lower resistivity than a channel formation region in the oxide semiconductor layer, the region being in contact with at least a part of the source and drain electrodes.