Embedded nanotransducer for ultrahigh-frequency SAW utilizing AlN/diamond layered structure

In this work, we report the development and realization of ultrahigh-frequency, high-performance nano interdigital transducers (n-IDTs) for generation of surface acoustic wave (SAW) on aluminum nitride (AlN)/diamond/Si substrates, where the metal fingers are embedded in the AlN film. The well-defined n-IDTs' resolution down to 200 nm were obtained using electron beam lithography, inductively coupled plasma (ICP) etching and lift-off processing. The fabricated SAW resonators exhibit response at a ultrahigh-frequency range, as high as 9.94 GHz, with stronger intensities of S
₁₁
peaks compared with normal transducer devices. The good high-frequency characteristics of the embedded n-IDTs and compatibility with existing fabrication technologies pave the way for the realization of advanced sensors and monolithic integrated MMICs on AlN/diamond/Si substrates for the high frequency and high power applications.