3D surface profilometry for both static and dynamic nanoscale full field characterization of AFM micro cantilever beams

Abstract

A static and dynamic 3-D surface profilometer with nano-scale measurement resolution was successfully developed using stroboscopic illumination and white-light vertical scanning techniques. Microscopic interferometry is a powerful technique for static and dynamic characterization of micro electromechanical systems (MEMS). As MEMS devices move rapidly towards commercialization, the issue of accurate dynamic characterization has emerged as a major challenge in design and fabrication. In view of this need, an interferometric microscopy based on white-light stroboscopic interferometry using vertical scanning principle was developed to achieve static and dynamic full-field profilometry and characterization of MEMS devices. A micro cantilever beam used in AFM was characterized using the developed instrument to analyze its full-field resonant vibratory behavior. The first five mode resonant vibration can be fully characterized and 3-5 nm of vertical measurement accuracy as well as tens micrometers of vertical measurement range can be achieved. The experimental results were consistent with the theoretical simulation outcomes from ANSYS. Using white-light stroboscopic illumination and white-light vertical scanning techniques, our approach has demonstrated that static and dynamic 3-D nano-scale surface profilometry of MEMS devices with tens-micrometer measurement range and a dynamic bandwidth up to 1MHz resonance frequency can be achieved.