Abstract
We fabricated micromechanical resonators using epitaxially grown GaNAs, in which in-plane tensile strain is induced by the growth on GaAs substrates. The resonators show significant improvement in resonance frequency and quality factor (Q) compared with those made of unstrained GaAs. The optimization of nitrogen concentration provides a resonator with the highest room-temperature Q value so far reported for III–V materials: the obtained Q of 1.2×105 is about 30 times higher than that of resonators made of GaAs. The ultrahigh-Q GaNAs mechanical resonators are suitable for various sensing applications to unveil phenomena that have not yet been possible to examine.