An optical capacitance-transient spectroscopy method was used to characterize defects in epitaxial 6H-SiC. The optical capacitance-transient spectroscopic measurements permitted the estimation of the optical ionization energy and the optical cross-section of these defects. Using deep-level transient spectroscopy, 3 peaks were observed, and 2 of them were identified as being E2 and R centers which were previously reported. The optical cross-sections for both centers were measured. By fitting the experimental data with theoretical curves for the optical cross-section, optical ionization energy of 1.58eV for the R center and 1.0eV for the E2 center were obtained. From the deep level transient spectroscopy measurements, the thermal activation energy of the R center was 1.30eV and that of the E2 center was 0.43eV. From these results and the previously reported capture energy barrier, the Franck–Condon shift was estimated to be 0.28eV for the R center and 0.62eV for the E2 center.

Characterization of Deep Levels in 6H-SiC by Optical Capacitance Transient Spectroscopy. Y.Nakakura, M.Kato, M.Ichimura, E.Arai, Y.Tokuda, S.Nishino: Journal of Applied Physics, 2003, 94[5], 3233-8