Study on a PECVD SiC-coated pressure sensor

In this paper, a PECVD silicon carbide (SiC) thin film which served as an anti-erosion protective layer for a pressure sensor is reported. Compared with an unprotected sample, influences of the SiC coating layer on properties of the pressure sensor, including sensitivity, temperature coefficient, chemical stability and long-term stability, were investigated. The results showed that the PECVD SiC layer decreased sensitivity by 11%, but it remarkably decreased the temperature coefficient by 20–70%. The PECVD SiC-coated pressure sensor was still intact after 20 min KOH etching, whereas the unprotected one was completely destroyed within 1 min. Therefore, this PECVD SiC-coated pressure sensor can not only work in erosive environments, but also has good sensitivity, high reliability and less temperature dependence.