Control of carrier lifetime of thick n-type 4H-SiC epilayers by high-temperature Ar annealing

摘要

We investigated the carrier lifetime and Z(1/2) center density of thick n-type 4H-SiC epilayers, which were oxidized and subsequently annealed in Ar at high temperatures. The Z(1/2) center density decreased below the detection limit in the region to, at least, a 130 mu m depth by thermal oxidation. After subsequent high-temperature annealing, the Z(1/2) center density increased with increasing annealing temperature, while the distribution of the Z(1/2) center density was nearly uniform to a 130 mu m depth. The carrier lifetime could be controlled from 26 to 2.4 mu by changing the annealing temperature from 1600 to 1800 degrees C. (C) 2016 The Japan Society of Applied Physics