SiC Capacitive Pressure Sensor Node for Harsh Industrial Environment

This paper presents an analytical and simulation solution for MEMS (Microelectromechanical Systems) capacitive pressure sensor operating in harsh environment. The proposed sensor consists of a circular SiC (Silicon Carbide) diaphragm suspended over sealed cavity on a Si (Silicon) substrate. SiC is selected in this work due to its excellent electrical stability, mechanical robustness and chemical inertness properties, which is very adequate for harsh environment. The design is based on the use of COMSOL multiphysics structural analysis to design and obtain analytical solution for a circular diaphragm deflection. The proposed sensor demonstrated diaphragm of 100 μm diameter with the gap depth 0.64 μm and the sensor exhibit a linear response with pressure load up to 3.5 MPa with maximum deflection up to 0.52 μm. Keywords-COMSOL; harsh environment; high dielectric materials; silicon carbide