| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor device with high productivity and low cost by omitting manufacturing processes; and a semiconductor device with reduced power consumption and increased reliability.SOLUTION: A semiconductor device used in a display device is manufactured through at least four photolithography processes, namely, forming a gate electrode, forming a source electrode and a drain electrode, forming a contact hole, and forming a pixel electrode, where a process for forming an island-shaped semiconductor layer is omitted. In the step for forming the contact hole, a groove portion in which a semiconductor layer is removed is formed, thereby preventing formation of a parasitic transistor. An oxide semiconductor is used for the semiconductor layer in which a channel is formed, and an oxide semiconductor having a higher insulating property than the semiconductor layer is formed over the semiconductor layer. |
