A novel MEMS SiC pressure sensor for high-temperature application

This paper designs a SiC (Silicon Carbide) non-contact capacitive pressure sensor for high-temperature application. The sensor is proposed to operate at high temperature environment due to its SiC -glass paste- SiC sandwiched structure. Mechanical performance of the sensor is verified by finite element analysis software and its MEMS process flow is also presented in detail. The SiC capacitive chip and external inductor coils composed a LC circuit for the purpose of extraction and measurement of pressure signal. The conversion between external pressure signal and resonance frequency signal of LC circuit is successfully achieved by wireless passive pressure measurement technology, providing a new way to solve the nonlinear test of variable-gap capacitive pressure sensor. Test result shows that resonant frequency and applied pressure have an inverse relationship under a range of 0-200kPa with a high sensitivity of 10.6 kHz/kPa. The design idea of the novel sensor provides a reference for the development of high-temperature pressure measurement.