This paper reports on the nanoscale imaging of a super-high-frequency (3–30 GHz) lateral overtone bulk acoustic resonator using transmission-mode microwave impedance microscopy (TMIM). The researchers visualized mode profiles of individual overtones, analyzed higher-order transverse spurious modes and anchor loss, and achieved a displacement sensitivity of 10 fm/√Hz at room temperature. The TMIM signals correlated well with the resonator's stored mechanical energy. This work advances the design and characterization of MEMS resonators for telecommunication, sensing, and quantum information science.

Daehun Lee, Shahin Jahanbani, Jack Kramer, Ruochen Lu, Keji Lai