论文部分内容阅读
One-port surface acoustic wave resonators (SAWRs) are fabricated on semi-insulating high-quality bulk GaN and GaN film substrates, respectively. The semi-insulating GaN substrates are grown by hydride vapor phase epitaxy (HVPE) and doped with Fe. The anisotropy of Rayleigh propagation and the electromechanical coupling coefficient in Fe-doped GaN are investigated. The difference in resonance frequency between the SAWs between [11 ˉ20] GaN and [1 ˉ100] GaN is about 0.25％for the Rayleigh propagation mode, which is smaller than that of non-intentionally doped GaN film (?1％) reported in the literature. The electromechanical coupling coefficient of Fe-doped GaN is about 3.03％, which is higher than that of non-intentionally doped GaN film. The one-port SAWR fabricated on an 8-μm Fe-doped GaN/sapphire substrate has a quality factor of 2050, and that fabricated on Fe-doped bulk GaN has a quality factor as high as 3650. All of our results indicate that high-quality bulk GaN is a very promising material for application in SAW devices.