A comparison of scanning microscopy cantilever force constants determined using a nanoindentation testing apparatus

The force constants of a variety of atomic force microscope (AFM) levers we re measured using a nanoindentation apparatus attached to an AFM. This meth od is both non-destructive and precise, with uncertainties in the measureme nt being less than 10%. The levers from ThermoMicroscopes(R), Nanosensors(R ), and NT-MDT were characterized. The results indicate that force constants generally fall within the manufacturers' broad specifications, but that va riations are large even for nominally identical levers from the same wafer. This variation suggests that variations in the mechanical properties and/o r thickness across the lever are large and have a length scale of the order of a few millimeters. It is also evident that the variation in force const ants is considerably larger for short levers than for long levers.