Measurement and Properties of High-Q GaN Nanowire Mechanical Resonators

We report on the measurement and observed properties of c-axis oriented, single crystal, gallium nitride nanowire (GaN NW) mechanical resonators. The NWs -- grown via molecular beam epitaxy -- behave as singly clamped beams, have lengths near 15 microns, radii near 100~nm, and resonant frequencies near 1 MHz. We observe mechanical quality factors, Q, defined as the ratio of resonant frequency to full width half maximum power, near room temperature often above 100,000. These high Q values are sensitive to NW surface conditions, which will change during processing and incorporation of NWs into devices. The use of a scanning electron microscope (SEM) allows for rapid surveying of as-grown samples and the measurement of individual NWs [1]. We also report on efforts to capacitively couple the NWs to a microwave resonant circuit, providing a completely electronic readout of NW ensembles. [1] S.M. Tanner et al., Appl. Phys. Lett. \textbf{91 }203117 (2007). We acknowledge support from NSF and DARPA (iMINT Center).