Hetero-epitaxial single crystal 3C-SiC opto-mechanical pressure sensor

The design, fabrication, early testing and material property assessment work related to the development of an opto-mechanical pressure sensor implemented with hetero-epitaxial 3C-SiC on silicon is described. The sensor is constituted by a single-crystal 3C-SiC membrane whose deflection upon pressure application is measured using a fiber-optic interferometric readout. The fabrication of sensor prototypes and micromachined 3C-SiC membranes for test purposes is described and the results of bulge tests on the membranes are reported. Functional characterization of the sensor prototypes in the pressure range 0-3 bar is also presented, showing good linearity and reproducibility of the sensor response, sensitivity of roughly 2 mV/bar and estimated pressure resolution around 0.5 bar on a 0-200 bar dynamic range.