Patent ID: 8785241

Claim:
A method for manufacturing a semiconductor device, comprising the steps of: forming a first wiring layer; forming an insulating layer covering the first wiring layer; forming a semiconductor layer over the insulating layer; forming a first conductive film over the semiconductor layer, a second conductive film over the first conductive film, and a third conductive film over the second conductive film; forming a resist mask over the third conductive film; performing etching including at least two steps on the first to third conductive films to form a second wiring layer having a three-layer structure; and removing the resist mask by a resist stripper after the etching step, wherein the two-step etching comprises: a first etching process performed until at least the first conductive film is exposed, and a second etching process performed under a condition that an etching rate for the first conductive film is higher than the etching rate in the first etching process and an etching rate for the semiconductor layer is lower than the etching rate in the first etching process, and wherein the resist stripper has properties of corroding the second conductive film.