Wafer-Level Fabrication of a Fused-Quartz Double-Ended Tuning Fork Resonator Oscillator Using Quartz-on-Quartz Direct Bonding

In this letter, a novel process to fabricate high-
Q
fused-quartz micromechanical resonators is demonstrated. Plasma-assisted quartz-on-quartz direct bonding at a low temperature in combination with quartz deep-reactive ion etching technique enables a simple wafer-level fabrication of self-mounted, electrostatically driven fused-quartz resonators. A 27-kHz capacitively transduced double-ended tuning fork fused-quartz resonator oscillator is successfully fabricated using the developed process. A high resonator
Q
-factor of 68000 is obtained, and the constructed oscillator shows a signal-to-noise ratio of 70 dB.