Fabrication of beam resonators from hot-wall chemical vapour deposited SiC

Single crystal and polycrystalline 3C–SiC have been grown in a hot-wall chemical vapour deposition reactor on 100 mm diameter p-type boron-doped (1 0 0) Si wafer. The crystal structure of the films has been determined by X-ray diffraction. Moreover, cantilever resonators have been fabricated from the two grown 3C–SiC films using a one-step dry etch and release process. The designed beam length has been varied between 50 and 200 μm. Resonant frequencies in the range between 110 kHz–1.5 MHz and 50–750 kHz have been obtained for single crystal and polycrystalline SiC devices, respectively. Furthermore, the experimental resonance frequencies have been used to calculate Young’s Modulus E for both types of SiC. The single crystal SiC has shown a relatively high Young’s Modulus (446 GPa) and should be an optimal material for RF–MEMS applications.