The piezoresistive properties research of SiC thin films prepared by RF magnetron sputtering

To research the piezoresistive properties of SiC thin films, a testing structure consisting of a cantilever beam, SiC thin films piezoresistors and a Cr/Pt electrode is proposed in this paper. The chips of testing structure were fabricated by micro-electro-mechanical system (MEMS) technology on a silicon wafer with < 100 > orientation, in which SiC thin films were deposited by using radio-frequency (13.56 MHz) magnetron sputtering method. The effect of sputtering power, annealing temperature and time on the microstructure and morphology of the SiC thin films were investigated by the X-ray diffraction (XRD) and scanning electron microscopy (SEM). It indicates that a good continuity and uniform particles on the SiC thin film surface can be achieved at sputtering power of 160 W after annealing. To verify the existence of Si-C bonds in the thin films, X-ray photoelectron spectroscopy (XPS) was used. Meanwhile, the piezoresistive properties of SiC thin films piezoresistors were measured using the proposed cantilever beam. The test result shows that it is possible to achieve a gauge factor of 35.1.