Read-out of micromechanical cantilever sensors by phase shifting interferometry

White light interferometry was applied to determine the bending of micromechanical cantilever sensors (MCS) with an error typically less than 1 per mille. Deflections smaller than 2 nm could be resolved at a lateral resolution of 2 mu m. Absolute values for curvatures can be determined and suitable reference points can be chosen on the MCS support. This was demonstrated in experiments using plasma polymerized polyallylamine films, which cross link upon ultraviolet light irradiation. The results suggest that 100 mu m long segments are sufficient to estimate reliable curvature radii of 450 mu m long microcantilever sensors. (c) 2005 American Institute of Physics.