Preparation method of novel SiC insulated gate dielectric based on thermal oxidation AlN dielectric layer

The invention discloses a preparation method of a novel SiC insulated gate dielectric based on a thermal oxidation AlN dielectric layer, and relates to the technical field of semiconductors. The preparation method comprises the steps of S10, carrying out standard RCA cleaning on the surface of a SiC epitaxial wafer; S20, placing the cleaned SiC epitaxial wafer in a chamber 1, introducing trimethylaluminum and ammonia gas, and growing an AlN dielectric layer on the upper surface of the SiC epitaxial wafer at the temperature T1, wherein the growth time is t1; and S30, putting the SiC epitaxial wafer on which the AlN dielectric layer grows into a chamber 2, introducing oxygen or mixed gas, and oxidizing part or all of the AlN dielectric layer at a temperature T2 for an oxidation time t2 to generate an AlON oxide layer. According to the embodiment of the invention, on the one hand, AlON with a higher forbidden band width is obtained by oxidizing AlN, and the leakage current of an SiCMOSFET device can be effective