Patent ID: 8637354

Claim:
A method for manufacturing a semiconductor device comprising the steps of: forming a semiconductor layer; stacking a first conductive film, a second conductive film, and a third conductive film in this order over the semiconductor layer; and performing at least three-stage etching on the first to third conductive films to form a wiring layer having a three-layer structure, wherein the three-stage etching comprises: a first etching process, which is performed until the first conductive film is exposed; a second etching process, which is 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 a third etching process, which is performed under the condition that etching rates for the first to the third conductive films are higher than the etching rates in the second etching process.