Metal oxide semiconductor field effect transistor and manufacturing method thereof

The invention discloses a metal oxide semiconductor field effect transistor and a manufacturing method thereof, and mainly solves the problems of overhigh on-resistance and overlarge saturation current of the existing field effect transistor. The field effect transistor comprises a substrate, two epitaxial layers, a groove, an insulating layer, a gate oxide layer, a shield gate electrode, an inter-electrode isolation layer, a gate electrode, three injection regions and two dielectric layers, the manufacturing method comprises the steps of firstly forming a first epitaxial layer and a second epitaxial layer which are different in conduction type on a substrate through an epitaxial growth technology, adopting a groove structure which penetrates through the second epitaxial layer and extends into the first epitaxial layer, and then sequentially generating an insulating layer, a gate oxide layer, a shielding gate electrode, an inter-electrode isolation layer and a gate electrode in a groove, and finally, forming