摘要 |
A semiconductor device includes a wiring embedded in an insulating layer, an oxide semiconductor layer over the insulating layer, a source electrode and a drain electrode electrically connected to the oxide semiconductor layer, a gate electrode provided to overlap with the oxide semiconductor layer, and a gate insulating layer provided between the oxide semiconductor layer and the gate electrode. The insulating layer is formed so that part of a top surface of the wiring is exposed. The part of the top surface of the wiring is positioned higher than part of a surface of the insulating layer. The wiring in a region exposed from the insulating layer is electrically connected to the source electrode or the drain electrode. The root-mean-square roughness of a region which is part of the surface of the insulating layer and in contact with the oxide semiconductor layer is 1 nm or less. |