Fabrication and testing of single crystalline 3C-SiC devices using a novel SiC-on-insulator substrate

Single crystal, 3C-SiC lateral resonant structures and piezoresistive strain gauges were fabricated on a novel SiC-on-Insulator (SiCOI) substrate. The SiCOI substrates were fabricated using a bonding-free, substrate growth and etch-back method that bypasses the problems associated with conventional methods to produce dielectrically-isolated 3C-SiC films. The process works equally well with SiO/sub 2/ and stoichiometric Si/sub 3/N/sub 4/ layers since bonding is not used; additionally, surface micromachining is enabled when SiO/sub 2/ is used. Lateral resonators fabricated from the 3C-SiC films exhibited Q values as high as 103,000. Using the 3C-SiC strain gauges, the /spl pi//sub 11/ piezoresistance coefficient was the largest, with a value of -17.8/spl times/10/sup -11/ Pa/sup -1/.