Patent attributes
A highly reliable semiconductor device the yield of which can be prevented from decreasing due to electrostatic discharge damage is provided. A semiconductor device is provided which includes a gate electrode layer, a gate insulating layer over the gate electrode layer, an oxide insulating layer over the gate insulating layer, an oxide semiconductor layer being above and in contact with the oxide insulating layer and overlapping with the gate electrode layer, and a source electrode layer and a drain electrode layer electrically connected to the oxide semiconductor layer. The gate insulating layer includes a silicon film containing nitrogen. The oxide insulating layer contains one or more metal elements selected from the constituent elements of the oxide semiconductor layer. The thickness of the gate insulating layer is larger than that of the oxide insulating layer.