| abstract |
A miniaturized transistor having highly stable electrical characteristics is provided. Furthermore, high performance and high reliability of a semiconductor device including the transistor is achieved. The transistor includes a first electrode, a second electrode, a third electrode, an oxide semiconductor layer, a first insulating layer, and a second insulating layer. The transistor includes a first region and a second region surrounded by the first region. In the first region, the first insulating layer, the second electrode, the oxide semiconductor layer, and the second insulating layer are stacked. In the second region, the first electrode, the oxide semiconductor layer, the second insulating layer, and the third electrode are stacked. |