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

Piezoresistance in n-type beta-SiC was analyzed on the basis of electron transfer and mobility shift mechanisms for cubic many-valley semiconductors. Gauge factors were calculated by using shear deformation potential constant Xi(u). 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 beta-SiC within the temperature range from 300 to 673 K, and impurity concentration range from 10(18) to 10(20) cm(-3). These conditions correspond to typical operation ranges of high-temperature piezoresistive sensors. The effect of the intervalley scattering on piezoresistance can be neglected from the evidence that gauge factor is inversely proportional to temperature within the abovementioned conditions. (C) 2002 American Institute of Physics.