MEMS Thermocouple Sensor Based on 4H-Silicon-Carbide-On-Insulator (4H-SiCOI)

With the high thermal conductivity and breakdown voltage, silicon carbide (SiC) has been treated as a promising material to work in harsh environment especially high temperature. However, due to its chemical inertness and wide band-gap, it is difficult to achieve the ion implantation, etching and good ohmic contact. In this study, silicon carbide on insulator (4H-SiCOI) is applied to fabricate MEMS thermocouple sensor, which can simultaneously compatible with bulk silicon CMOS process. The stress and temperature distribution of the sensor was simulated by COMSOL. After optimized the process parameters, the sensor based on 4H-SiCOI was successfully fabricated. Preliminary test results demonstrated the sensor shows good sensitivity about 1.44 $\times 10^{-{8}}\,\,{V}{m}^{{{2}}}/{W}$ and response time of 3.24ms, which also keeps good linearity and repeatability. This sensor can satisfy the needs of fast and high precision heat detection and our work may have a meaningful reference value for other same type SiC-based MEMS thermocouple sensor design and preparation.