Complementary metal-oxide semiconductor-compatible silicon carbide pressure sensors based on bulk micromachining

This Letter presents a complementary metal-oxide semiconductor-compatible silicon carbide (SiC) absolute capacitive pressure sensor for harsh environmental applications. The pressure sensor was fabricated by bulk micromachining technology. Low-temperature SiC film was deposited by the plasma-enhanced chemical vapour deposition process and utilised as the moveable membrane of the device. Even though the deposited film has a good mechanical property and high chemical resistance, it takes low electric conductivity, thus tungsten(W) was used as the sensor´s electrodes. This pressure sensor exhibits a linear response over a pressure range of 2 bars, with a total change of 507.1 mV (i.e. 0.274 pF). Furthermore, it is confirmed to withstand KOH etching for more than 30 min.