Method for manufacturing gate oxide layer of novel SiC MOSFET (Metal Oxide Semiconductor Field Effect Transistor) device

The invention discloses a method for manufacturing a gate oxide layer of a novel SiC MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) device. The method comprises the following steps: forming an N + silicon carbide substrate; the P well regions are symmetrically arranged on two sides of the front surface of the N + silicon carbide substrate; the N + ion implantation region is arranged in the P well region; the nitrogen atom pre-injection layer is arranged on the N + silicon carbide substrate, the P well region and the N + ion injection region; and the gate oxide layer is arranged on the nitrogen atom pre-injection layer. According to the method, the nitrogen atoms are pre-injected before the gate oxide layer is oxidized, and high-temperature annealing is carried out after deposition of the gate oxide layer is completed, so that the nitrogen atoms fill C lattice vacancies in the oxidation process, the interface state density of SiC and SiO2 is reduced, the quality of the gate oxide layer is improved,