The invention discloses a method for prolonging the service life of a SiC epitaxial minority carrier, and relates to the field of
semiconductor materials. The method comprises the following steps: S1, after a
SiC substrate is subjected to standard cleaning, epitaxially growing an epitaxial layer with the thickness of more than 10 microns; s2, carrying out standard cleaning again, carrying out high-temperature oxidation on the 4H-SiC epitaxial
wafer in an O2
atmosphere, forming a SiO2
oxide layer and partial interstitial carbon atoms and carbon clusters on the SiC surface, and carrying out NO high-temperature
passivation annealing; s3, removing a
surface oxide layer of the SiC epitaxial
wafer subjected to high-temperature oxidation and surface
passivation treatment by using a BOE solution, and performing standard cleaning again; s4, putting the SiC epitaxial
wafer into a high-temperature annealing device, raising the temperature, reducing the pressure intensity of a furnace chamber, and performing low-pressure
hydrogen annealing on the SiC epitaxial wafer in an H2
atmosphere; and S5, repeating the steps S2 to S4. High-temperature oxidation and low-pressure
hydrogen annealing are combined, so that the time required by high-temperature oxidation is shortened, the epitaxial wafer with longer minority
carrier lifetime is obtained, and the minority
carrier lifetime of N and P type SiC can be effectively prolonged.