Influence of Au-Based Metallization on the Phase Velocity of GaN on Si Surface Acoustic Wave Resonators

This letter presents a comparison between the phase velocity of Al and Ti/Au metallized GaN/Si-based surface acoustic wave structures. The resonance frequency (and consequently the phase velocity) is higher for Ti/Au-based metallization, especially when the acoustic wavelength has comparable values with the GaN layer thickness. Simulation results are in excellent agreement with the experiment. For...