Design, Fabrication, and Test of 4H-SiC Accelerometer

Silicon carbide (SiC) is a promising material to fabricate MEMS accelerometers used in extreme environments. Due to the difficulties of processing bulk SiC materials and the complex structure of accelerometers, studies on SiC accelerometers are still insufficient. In this study, we designed a single-beam accelerometer based on 4H-SiC. The traditional MEMS process is used to fabricate the piezoresistors and electrodes. The femtosecond laser etching is used to thin the cantilever beam and release the proof mass. Static and dynamic tests of the accelerometer were carried out. The zero-g output remained stable in one one-hour test. The sensitivity of the accelerometer was 0.099 mV/g in the ±1 g static earth gravity test, and the nonlinearity of the sensor was calculated to be 0.34%. The dynamic testing of the sensor showed that the designed sensor can accurately identify the vibration frequency and can effectively reflect the vibration signal after noise reduction.