Intrinsic defects in epitaxial semi-insulating 4H-SiC, prepared by low-pressure chemical vapour deposition, were studied by using electron spin resonance at various illumination times. The results showed that the intrinsic defects in as-grown 4H-SiC consisted of carbon vacancy (VC) and complex-compound related VC. There were two other peaks in the ESR spectra following illumination with Xe light, which were attributed to VSi and VCCSi. The illumination time changed the relative density of the intrinsic defects in 4H-SiC. The relative density of the intrinsic defects attained a maximum when the illumination time was 2.5min, and the ratio of VC to complex compounds was simultaneously minimized. It was deduced that some VSi could be transformed into the complex-compound related VC by the illumination.

ESR Characters of Intrinsic Defects in Epitaxial Semi-Insulating 4H-SiC Illuminated by Xe Light. P.Cheng, Y.Zhang, Y.Zhang, H.Guo: Journal of Semiconductors, 2009, 30[12], 123002