Design considerations for bulk micromachined 6H-SiC high-G piezoresistive accelerometers

We report the utilization of key design parameters to simulate, batch-fabricate and evaluate first-generation single crystal 6H-SiC piezoresistive accelerometers for extreme impact, high electromagnetic fields (EM) and high temperature applications. The results from finite element analysis (FEA) of the selected design models were compared to evaluated prototypes. While FEA results predicted safe operation above 100,000-g's, preliminary experimental tests were performed up to 40,000-g's. Sensitivities ranging between 50 and 343 nV/g were measured. Non-linear behavior was observed over the shock range relative to the commercial accelerometer used as a benchmark. These initial results offer promise for the use of 6H-SiC accelerometers for extreme impact sensing in strong EM fields and temperature up to 600/spl deg/C that are beyond the capability of silicon.