Development of plasma-free etch chemistry to realize defect-free GaAs micromechanical resonator structures

Figure 1. Evolution of InGaP etch front in 12M HC1 solution. Top layer is 500 nm thick GaAs. InGaP layer is 500 nm thick on GaAs (001) substrate.

Figure 2. Cross-sectional SEM micrograph of under 500 nm GaAs suspended by etched InGaP layer (above) and resulting GaAs resonator structures (2 mm wide) of varying lengths (and aspect ratios).