The Piezoresistive Effect of p-type Single Crystalline 3C-SiC for Mechanical Sensors

Abstract

Silicon carbide (SiC) is a promising material for electronic devices operating at high temperatures, thanks to its large energy band gap, superior mechanical prop- erties and excellent chemical inertness. Among various poly types of SiC, cubic single crystalline silicon carbide (3C-SiC) is considered to be the most suitable poly type for MEMS applications, as it can be grown on a Si substrate which is com- patible with the conventional MEMS process and reduces the cost of SiC wafers. Studies on the piezoresistive effect of 3C-SiC are of great interest for developing mechanical sensors such as pressure sensors and strain sensors used for controlling combustion and deep well drilling. This research aims to experimentally charac- terize and theoretically analyze the piezoresistive effect of p-type single crystalline 3C-SiC grown on a large scale Si substrate. The gauge factor, the piezoresistive coefficients in two-terminal and four-terminal resistors, the comparison between single crystalline and nano crystalline SiC, as well as the temperature dependence of the piezoresistive effect in p-type 3C-SiC are also addressed. The large gauge factors of the p-type 3C-SiC at both room temperature and high temperatures found in this study indicated that this poly type is feasible for the development of mechanical sensing transducers used in harsh environments with high temperatures.