The annealing behavior of irradiation-induced deep levels in n-type 6H-material was studied by using deep-level transient spectroscopy. Annealing revealed that the predominant deep-level transient spectroscopy signal at Ec - 0.36eV (E1) consisted of 2 overlapping deep levels (ED3L, ED3H). The break-up temperature of the ED3L defect was about 700C. The ED3H center, together with another deep level located at Ec - 0.44eV (E2), could withstand annealing at up to 1600C. It was suggested that the involvement of ED3L explained why various E1/E2 concentration ratios had been observed previously. A revised value of the capture cross-section of the deep-level, ED3H, was deduced after removing ED3L by annealing. A deep level found at Ec - 0.50eV was identified as being a vacancy-impurity complex since it was found to have a lower saturated concentration, and weak thermal stability. Two other deep levels, Ec - 0.27eV and Ec - 0.32eV, were also reported. These had not been observed by others, because of the carrier freeze-out effect.

Electron-Irradiation Induced Deep Levels in n-Type 6H-SiC. M.Gong, S.Fung, C.D.Beling, Z.You: Journal of Applied Physics, 1999, 85[11], 7604-8