Evaluation of Long Carrier Lifetimes in Very Thick 4H-SiC Epilayers
We investigate the carrier lifetimes in very thick 4H-SiC epilayers (~250 μm) by means of time-resolved photoluminescence and microwave photoconductive decay. Both the minority carrier lifetime and the high injection lifetime are found to reach 18.5 μs by applying the carbon implantation/annealing method to the as-grown epilayers. We also study the epilayer thickness dependence of the carrier lifetime by successive experiments involving lifetime measurement and polishing. Based on the relationships between epilayer thickness and carrier lifetime, the bulk carrier lifetime and the hole diffusion constant are discussed.
Edouard V. Monakhov, Tamás Hornos and Bengt. G. Svensson
T. Miyazawa et al., "Evaluation of Long Carrier Lifetimes in Very Thick 4H-SiC Epilayers", Materials Science Forum, Vols. 679-680, pp. 197-200, 2011