Micromechanical resonators fabricated from lattice-matched and etch-selective GaAs∕InGaP∕GaAs heterostructures

Abstract

Utilizing lattice-matched GaAs∕InGaP∕GaAs heterostructures, clean micromechanical resonators are fabricated and characterized. The nearly perfect selectivity of GaAs∕InGaP is demonstrated by realizing paddle-shaped resonators, which require significant lateral etching of the sacrificial layer. Doubly clamped beam resonators are also created, with a Q factor as high as 17 000 at 45mK. Both linear and nonlinear behaviors are observed in GaAs micromechanical resonators. Furthermore, a direct relationship between Q factor and resonant frequency is found by controlling the electrostatic force on the paddle-shaped resonators. For beam resonators, the dissipation (Q−1) as a function of temperature obeys a power law similar to silicon resonators.