Piezoresistance consideration on n-type 6H SiC for MEMS-based piezoresistance sensors

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 or coefficients for piezoresistive sensor application, i.e., the longitudinal, transverse and shear, 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 the piezoresistance in n-type 6H SiC within the temperature range from 300 K to 773 K, and impurity concentration n = 2 x 10(19) to 3.3 x 10(19) cm(-3). These conditions correspond to typical operation ranges of state-of-the-art MEMS-based piezoresistive sensors.