| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of manufacturing a transistor that has stable electric characteristics and that has less signal delay caused by wiring resistance, in a semiconductor device using an oxide semiconductor film, and to provide a semiconductor device having the transistor, and a high-performance display device having the transistor.SOLUTION: As a method of manufacturing a source electrode and a drain electrode contacted with an oxide semiconductor film, a first metal film 112a and a second metal film 112b are formed, and a first photolithography step is performed on the second metal film, and a part of the second metal film is removed by first etching. Thereafter, a third metal film 112c is formed on the first metal film and the second metal film, and a second photolithography step is performed on the third metal film, and a part of the first metal film and the third metal film is removed by second etching. In addition, at the second etching, the first metal film and the third metal film are removed outside an end part of the second metal film removed by the first etching.SELECTED DRAWING: Figure 4 |
