Silicon carbide capacitive pressure sensors with arrayed sensing membranes

Silicon carbide absolute capacitive pressure sensors with arrayed sensing membranes was designed and fabricated based on silicon-glass anodic bonding. The sensing membranes consist of multiple layers of SiC/Au/SiC, making the device promising to be applied in corrosive environment. The fabricated sensor was integrated with a capacitor read-out circuit in a size of 22 × 23 × 9 mm³, and then packaged by PDMS, which serves as the coating layer of the electrodes. The packaged sensor remained nearly the same linear response after 60-minutes 30% KOH etching as the one before PDMS packaging, i.e. the sensor with a 5×5 array of 100×100 μm² square sensing membranes demonstrates a sensitivity of 0.021 pF/bar over a pressure range from 0.5 bar to 5 bar, and then modified to 0.023pF/bar after KOH etching.