Oxidation-Process Dependence of Single Photon Sources Embedded in 4H-SiC MOSFETs

We investigated single photon sources (SPSs) in 4H-SiC metal-oxide-semiconductor field-effect transistors (MOSFETs) by means of confocal microscope techniques. We found SPSs only in 4H-SiC/SiO2 interface regions of wet-oxide C-face MOSFETs. The other regions of MOSFETs such as source, drain and well did not exhibit SPSs. The luminescent intensity of the SPSs at room temperature was at least twice larger than that of the most famous SPSs, the nitrogen-vacancy center, in diamond. We examined four types of C-face and Si-face 4H-SiC MOSFETs with different oxidation processes, and found that the formation of the SPSs strongly depended on the preparation of SiC/SiO2 interfaces.