Dynamic out-of-plane profilometry for nano-scale full-field characterization of MEMS using stroboscopic interferometry with novel signal deconvolution algorithm

Abstract

A dynamic 3D nano-scale surface profilometer using stroboscopic white-light interferometry with novel signal deconvolution was developed to deliver dynamic surface profilometry with a measurement bandwidth of up to a MHz scale and a vertical resolution reaching 1 nm. Previous work using stroboscopic microscopic interferometry for dynamic characterization of micro-(opto)electromechanical systems (M(O)EMS) has been limited in measurement bandwidth of less than a few hundred kHz due to physical length limitation of stroboscopic light. For high-resonance mode analysis, the stroboscopic light pulse is too lengthy to capture the moving fringes from dynamic motion of the detected structure. In view of this need, a novel deconvolution algorithm using correction of the light response was developed for removing potential image blurs caused by the unavoidable vibration of the tested parts. With this advance in technology, the bandwidth of dynamic measurement can be significantly increased without sacrificing measurement accuracy. A microcantilever beam used in AFM was measured to verify the capability of the system in accurate characterization of dynamic behaviors of M(O)EMS.