Atomic Force Microscopy characterization of electromechanical properties of RF acoustic bulk wave resonators

In this paper we demonstrate the ability of Atomic Force Microscopy (AFM) in combination with a lock-in detection technique for the characterization of the electromechanical properties of acoustic bulk wave resonators. In particular, this method is applied to study the mechanical frequency response and the acoustic mode shapes of the Agilent Technologies´ Film Bulk Acoustic Resonator (FBAR). The mechanical resonance frequencies of the FBARs in the GHz range are measured in air, and the shape of the acoustic modes is obtained over 100×100 μm areas with nanometer-scale lateral resolution and angstrom-scale vertical resolution.