MANUFACTURING METHOD FOR SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a technique for manufacturing a semiconductor device including a transistor with high performance and high reliability.SOLUTION: A protective conductive film for protecting an oxide semiconductor layer when a wiring layer is formed of a conductive layer is formed between the oxide semiconductor layer and the conductive layer, and then etching is performed in two stages. The first etching process employs an etching method performed under the condition in which the protective conductive film is etched less easily than the conductive layer and the etching selective ratio between the conductive layer and the protective conductive film is high. The second etching process employs an etching method performed under the condition in which the protective conductive film is etched more easily than the oxide semiconductor layer and the etching selective ratio between the protective conductive film and the oxide semiconductor layer is high.SELECTED DRAWING: Figure 1