The fluence-dependent properties and the annealing behavior of electron-irr
adiation-induced deep levels in n-type 6H-SiC have been studied using deep-
level transient spectroscopy (DLTS). Sample annealing reveals that the domi
nant DLTS signal at E-C-0.36 eV (labeled as E1 by others) consists of two o
verlapping deep levels (labeled as ED3L and ED3H). The breakup temperature
of the defect ED3L is about 700 degrees C. The ED3H center together with an
other deep level located at E-C-0.44 eV (so-called E2) can withstand high-t
emperature annealing up to 1600 degrees C. It is argued that the involvemen
t of the defect ED3L is the reason that various concentration ratios of E1/
E2 were observed in the previous work. The revised value of the capture cro
ss section of the deep-level ED3H has been measured after removing ED3L by
annealing. A deep level found at E-C-0.50 eV is identified as a vacancy-imp
urity complex since it was found to have a lower saturated concentration an
d weak thermal stability. Two other deep levels, E-C-0.27 eV and E-C-0.32 e
V, which were not observed by others because of the carrier freeze-out effe
ct, are also reported. (C) 1999 American Institute of Physics. [S0021-8979(
99)07911-6].