Measuring the profile and out-of-plane motion of microstructures using microscopic interferometry with FTM analysis

Abstract

Microscopic interferometry is up to now the most widely used technique for microstructure surface profiling, and is also capable of measuring out-of-plane motion and deflection of microstructures with stroboscopic illumination. In this paper we put forward a stroboscopic Mirau microscopic interferometer system, which is built of commercially available components and instruments based on virtual instrument technology. An improved Fourier transform method (FTM) is described, and two interferograms with different phase shifting are processed for achieving reliable phase demodulation. The system is applied to the measurement of microcantilever surface profile and out-of-plane deflection and motion. Finally, experiment results are compared with that of temporal phase-shifting method for validating the process method.