Metal oxide semiconductor device and method of manufacturing same

The invention provides a metal oxide semiconductor device and a manufacturing method thereof. The device comprises a substrate, wherein a source region extends into the substrate from the upper surface of the substrate and has a first doping type; a gate structure is located on the upper surface of the substrate, the gate structure at least exposes the source region, the semiconductor layer is located on the upper surface of the substrate and has a first doping type, the semiconductor layer is used as a partial voltage-withstanding region of the device, the source region is located on the first side of the gate structure, and the source region is located on the second side of the gate structure; the semiconductor layer is located on the second side of the gate structure, and the first sideand the second side of the gate structure are opposite. According to the metal oxide semiconductor device and the manufacturing method thereof, the size of the device is reduced, the manufacturing process is simple, and the