Method for improving vertical-conductive structured SiC MOSFET (Metal-Oxide -Semiconductor Field Effect Transistor) channel mobility

An embodiment of the invention relates to a method for improving the vertical-conductive structured SiC MOSFET (Metal-Oxide -Semiconductor Field Effect Transistor) channel mobility. The method comprises steps of forming an N-drift region of a MOSFET on an N+SiC substrate through the epitaxial technology; forming a source region of the MOSFET in the N-drift region through the injection technology; subjecting the epitaxial surface of a SiC epitaxial wafer with the formed source region to ultraviolet ray oxidation at 200 DEG; performing RCA cleaning to form a Si interface structure on the epitaxial surface; subjecting the SiC epitaxial wafer to plasma enhanced chemical vapor deposition (PECVD) pretreatment in the oxygen atmosphere at 300 DEG, and oxidizing the Si interface structure of the epitaxial surface into a SiO2 interface layer; performing oxidation deposition and annealing on the SiO2 interface layer to form an isolation dielectric layer; and preparing a polycrystalline silicon gate and source and drain metal electrodes, thereby forming a vertical-conductive structured SiC MOSFET.