A CMOS compatible SiC accelerometer

In this paper we describe the fabrication process and preliminary results of a CMOS compatible surface micromachined vertical accelerometer. The vertical accelerometer together with lateral one fabricated in the same process creates 3D surface micromachined accelerometer. PECVD silicon carbide and aluminium layers were used as mechanical material and electrodes, respectively. As the maximum processing temperature is 400°C, the sensor can be made on top of the CMOS readout circuit as post-processing module. The sensor is designed to operate in range -5/+5g with sensitivity 1.8fF/g and 2.3f.F/g in vertical and lateral direction, respectively. The sensor has been fabricated and is under measurement. The initial measurement shows that the initial capacitance of vertical accelerometer is 0.42pF.