Q factor enhancement of Si resonator by nonlinear damping

The nonlinear damping effect of thin cantilevered Si resonators with thicknesses of 100–1500 nm is investigated from the measurements of the Q factor change versus the vibration amplitude. The Q factor of the 100 nm-thick resonator largely increases as its vibration amplitude become larger due to its large nonlinear damping effect, while the Q factor increment of the thicker resonators (400, 800, 1500 nm of thickness) becomes smaller. The surface condition of the Si resonator also has an interaction to the amplitude dependence on the Q factor. The H₂ annealing increases the Q factor change with increasing the amplitude, and the Ar plasma treatment is vice versa. These results show that Si resonators exhibit the nonlinear damping effect, and the large Q factor enhancement by this effect is markedly observed in the thin resonator. The nonlinear damping constant of the 100 nm-thick Si resonator was −1.12 × 10¹¹ kg/m²s.