Temperature-dependent internal friction in silicon nanoelectromechanical systems

The mechanical properties of micro- and nanomechanical systems are of interest from both fundamental and technological standpoints. High-frequency mechanical resonators presenting high quality factors are of interest for the development of sensitive force detecting devices, and highly efficient RF electromechanical filters and oscillators. Internal losses are the combination of both extrinsic and intrinsic issues that must be well understood for the optimization of resonator quality, and for the experimental access to fundamental nanoscopic mechanical phenomena. The temperature dependent internal friction in 1-10 MHz paddle oscillators is reported. Quality factors as high as 1000 and 2500 are observed at room temperature in metallized and non-metallized devices, respectively. Internal friction peaks are observed in all devices in the T = 160-180 K range. The position of those peaks is consistent with the Debye relaxation of previously reported surface and near-surface phenomena.