Dominated energy dissipation in ultrathin single crystal silicon cantilever surface loss

The effect of surface treatment in UHV chamber on Q factor of cantilevers with different thickness (60 nm, 170 nm and 500 nm) and different surface orientation was investigated. When length L>30 μm, Q factor is proportional to thickness, surface loss dominates. While L<30 μm, support loss surpasses the surface loss. Heating can remove SiO₂ layer and absorbates, and result in an increase of Q factor. Hydrogen termination leads to a larger relative increase of Q factor in thinner structure than in thicker ones. Heating and H exposure improve Q values of Si(100) oriented cantilevers more than Si(110) oriented ones and result in the contrary resonance frequency response for these two surfaces