Deep Acceptor Levels of the Carbon Vacancy-Carbon Antisite Pairs in 4H-SiC
The SI-5 electron-paramagnetic-resonance (EPR) centre is a dominant defect in some high-purity semi-insulating (HPSI) SiC substrates and has recently been shown to originate from the negatively charged carbon vacancy-carbon antisite pair (VC − Si C ). In this work, photoexcitation EPR (photo-EPR) was used for determination of the energy position of deep acceptor levels of VCCSi in 4H-SiC. Our photo-EPR measurements in slightly n-type material show an increase of the EPR signal of VC − Si C for photon energies from ~0.8 eV to ~1.3 eV. Combining the data from EPR, deep level transient spectroscopy and supercell calculations we suggest that the (1–|2–) levels of the different configurations of the defect are located in the range ~0.8-1.1 eV below the conduction band.
N. Wright, C.M. Johnson, K. Vassilevski, I. Nikitina and A. Horsfall
P. Carlsson et al., "Deep Acceptor Levels of the Carbon Vacancy-Carbon Antisite Pairs in 4H-SiC", Materials Science Forum, Vols. 556-557, pp. 449-452, 2007