Electron Mobility Measurements in SiC Polytypes

Abstract

Electron mobilities were measured in a number of n-type SiC samples selected and prepared in such a way as to ensure that they were single polytype specimens of 6H, 15R, or 4H. In the purest samples from the same growth preparation the ratio of 15R to 6H mobilities was found to be about 1.7 with both polytypes having a temperature dependence of mobility near T−2.4 between 300° and 800°K. Room-temperature mobilities of these specimens were about 300 and 500 cm2 V−1 sec−1, respectively, for 6H and 15R. Only two 4H samples were measured, but these showed even higher mobilities than 15R polytype samples.