Thin film quartz layer reported on silicon

For the first time, in this work, we report on the transfer of single crystal quartz layers onto silicon wafer through wafer bonding and grinding. A Film Bulk Acoustic Resonator (FBAR) made of a free standing quartz membrane vibrating on the thickness-shear mode has been achieved using this approach. Electrical measurements have been achieved for various temperature conditions. The obtained resonators exhibit fundamental resonance frequencies close to 200 MHz for the fundamental mode. The electromechanical coupling factor is about 0.4 % and the temperature coefficient of frequency is near +26 ppm/°C. These first electrical results highlight the quality piezoelectric response of the reported layer conforms to the bulk material properties.