Silicon carbide UMOSFET device integrated with HJD and preparation method thereof

The invention discloses a silicon carbide UMOSFET device integrated with an HJD and a preparation method of the silicon carbide UMOSFET device, and relates to the technical field of semiconductors. The epitaxial layer is positioned on one side of the substrate; the first injection region and the second injection region are arranged at an interval and are respectively positioned on one side, deviating from the substrate, of the epitaxial layer; the polycrystalline silicon layer is located between the first injection region and the second injection region and located on the side, away from the substrate, of the epitaxial layer, and the polycrystalline silicon layer and the epitaxial layer are in heterojunction contact; and the source electrode is located on the sides, away from the substrate, of the first injection region, the second injection region and the polycrystalline silicon layer, and the source electrode at least partially covers the first injection region, the second injection region and the polycryst