| abstract |
A semiconductor device using an oxide semiconductor and using an oxide semiconductor with high reliability, which achieves miniaturization while maintaining good electrical characteristics. A transistor is provided over a substrate and is located on the island-shaped semiconductor layer, the pair of electrodes that are electrically connected to the semiconductor layer, and the semiconductor layer. And a gate electrode 105 located on the gate insulating layer 104 and overlapping the semiconductor layer 102. A first protective insulating layer 111 is provided between the substrate 101 and the semiconductor layer 102. In addition, a second protective insulating layer 112 is provided over the pair of electrodes 103 and the gate electrode 105. Further, the first protective insulating layer 111 and the second protective insulating layer 112 are provided in contact with each other in a region where the pair of electrodes 103 and the gate electrode 105 are not provided. [Selection] Figure 1 |