Semiconductor device and method for manufacturing semiconductor device

A semiconductor device comprising:

• a substrate including an embedded insulation film and a semiconductor layer that is provided on the embedded insulation film and on which a semiconductor element is formed;
• a gate electrode provided on the semiconductor layer,
• wherein the gate electrode includes a band-shaped first electrode portion that extends from a center portion of the semiconductor layer and beyond an end of the semiconductor layer along a first direction in a case where the substrate is viewed from above,
• wherein in a cross section in a case where the first electrode portion and the substrate are cut along the first direction, a film thickness of the end of the semiconductor layer is thicker than a film thickness of the center portion of the semiconductor layer,
• wherein a silicon oxide film surrounding the semiconductor layer such that the film thickness of the end of the semiconductor layer is thicker than a film thickness of the silicon oxide film, and
• wherein a source contact via and a drain contact via are provided on the center portion of the semiconductor layer having a film thickness thinner than the film thickness of the end of the semiconductor layer.