Simulation and experimental studies of the dissolution corrosion of 4H-SiC in liquid Pb/Bi

The dissolution corrosion of liquid Pb/Bi on 4H-SiC (0001) surfaces are studied based on first-principles calculations and experimental studies. The calculation models of 4H-SiC (0001) surfaces are proposed according to the experimental results, and the rationality of the models is verified by our repeated experiments. Clean surface stability is mainly determined by the strength of surface states due to the dangling bonds. Pb/Bi adatoms accelerate the dissolution of C atoms more severely than that of Si atoms and liquid Bi is more corrosive than liquid Pb, which are consistent with our experimental results. Energetics, microstructural and electronic properties are analyzed to reveal the corrosion mechanism of liquid Pb/Bi. Moreover, we provide a theoretical scheme to improve the corrosion resistance of 4H-SiC by adjusting the charges of vacancies and changing the relative position of Fermi level.