Patent ID: 9640642
Date: 2017-05-02
CPC Classifications: H01L

Claim:
1. A method for manufacturing a semiconductor device, comprising the steps of: forming an oxide semiconductor layer; forming a stack of conductive films on the oxide semiconductor layer, wherein the stack comprises a first conductive film on the oxide semiconductor layer, a second conductive film on the first conductive film, and a third conductive film on the second conductive film; selectively etching the stack until the first conductive film is exposed, and selectively etching the first conductive film until the oxide semiconductor layer is exposed, wherein the oxide semiconductor layer is not overlapped with a first end portion of the first conductive film, a first end portion of the second conductive film, and a first end portion of the third conductive film, and wherein the first end portions of the first conductive film, the second conductive film, and the third conductive film are not aligned with each other.