Electrically detected-magnetic-resonance identifications of defects at 4H-SiC(0001¯)/SiO2 interfaces with wet oxidation

Abstract

We present electrically detected-magnetic-resonance (EDMR) identification of major and minor interface defects at wet-oxidized 4H-SiC(0001¯)/SiO2 interfaces for C-face 4H-SiC metal-oxide-semiconductor field-effect transistors. The major interface defects are identified as c-axial types of carbon-antisite-carbon-vacancy (CSiVC) defects. Their positive (+1) charge state generates a spin-1/2 EDMR center named “C-face defects” and behaves as an interfacial hole trap. This center is responsible for the effective hydrogen passivation of the C face. We also identify a minor type of interface defect at this interface called “P8 centers,” which appear as spin-1 centers. Judging from their similarity to the P7 centers (divacancies, VSiVC) in SiC, they were assigned to be a sort of basal-type interfacial VSiVC defect. Since both the CSiVC and VSiVC defects are known as promising single photon sources (SPSs) in SiC, the wet oxidation of the C face will have good potential for developing SPSs embedded at SiC surfaces.