Effects of Electron Irradiation on Deep Centers in High-Purity Semi-Insulating 6H-SiC

Autor: G. C. Farlow, Z-Q. Fang, David C. Look, Bruce B. Claflin
Rok vydání: 2007
Předmět:
Zdroj: Journal of Electronic Materials. 36:307-311
ISSN: 1543-186X
0361-5235
DOI: 10.1007/s11664-006-0031-2
Popis: Many point-defect–related centers have been investigated in electron-irradiated 6H-SiC by deep-level transient spectroscopy (DLTS). Most of them are believed to be related to vacancies. Our DLTS studies on deep centers produced by electron-irradiation (EI) in conductive epi-6H-SiC are in agreement with the literature data. However, for semi-insulating SiC, DLTS cannot be used for trap studies so we have applied thermally stimulated current (TSC) spectroscopy. At least nine TSC traps have been observed in high-purity/semi-insulating (HPSI) 6H-SiC. To understand the nature of these centers, 1-MeV EI and postirradiation annealing at 600°C were applied to the sample. The TSC spectroscopy and 4.2 K photoluminescence (PL) have been used to study the effects of EI and annealing on the centers in HPSI 6H-SiC. It was found that (1) some of the major EI-induced DLTS centers in conductive 6H-SiC, such as ED1, E1/E2, Ei, Z1/Z2, and L9, have TSC counterparts even in as-grown HPSI 6H-SiC; (2) EI-induced TSC centers in HPSI 6H-SiC are due to point defects, which have been confirmed by typical PL lines (such as S, L, and V lines); and (3) the concentration of the 1.1-eV center, which controls material conductivity, can be increased by 1-MeV EI and decreased by 600°C annealing.
Databáze: OpenAIRE
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