Single-crystal aluminum nitride nanomechanical resonators

Aluminum nitride is a light, stiff, piezoelectrically active material that can be epitaxially grown on single-crystal Si. AlN is beginning to play a role in the integration of semiconducting electronic and surface acoustic wave devices, and may prove useful for the integration of other types of mechanical devices as well. We describe the growth and subsequent electron-beam patterning and etching of epitaxial AlN-on-silicon films into nanomechanical flexural resonators. We have measured resonators with fundamental mechanical resonance frequencies above 80 MHz, and quality factors in excess of 20 000.