SCANNING FORCE MICROSCOPE USING A PIEZOELECTRIC MICROCANTILEVER

This paper presents a simple force microscope that makes a use of a piezoelectric microcantilever for sensing its vibration amplitude. The microcantilever is a composite beam, which consists of a piezoelectric ZnO thin film and a thermal SiO2 film, and has a ZnO whisker tip at its end. The cantilever used has the first natural resonance frequency of 140 kHz and the calculated spring constant of 14 N/m. Vibration amplitude of the lever driven near its resonance frequency by external oscillator was sensed by detecting the induced piezoelectric charge. The output charge with the lever amplitude of 1.0 nm was 0.028 fC. The microscope was operated in cyclic contact mode. Recordings of the output versus the sample position and imaging of deposited Au film surface were successfully performed in air. We present two kinds of cyclic contact forces which were calculated from parameters of the lever used.