Analysis of piezoresistance in n-type 6H SiC for high-temperature mechanical sensors

Abstract

Piezoresistance in n-type 6H SiC was analyzed on the basis of electron transfer and mobility shift mechanisms for hexagonal many-valley semiconductors. Three important gauge factors for piezoresistive sensor application, i.e., the longitudinal-, transverse-and shear gauge-factors, were calculated by using band parameters. The calculation was compared with experimental results taken from the literature. It was shown that incorporation of the electron transfer and the mobility shift mechanisms gives reasonable interpretation for piezoresistance in n-type 6H SiC within temperature range from 300 K to 523 K, and impurity concentration at n=3.3/spl times/10/sup 19/ cm/sup -3./ These conditions correspond to typical operation ranges of high-temperature piezoresistive sensors.