Standardized procedure for calibrating height scales in atomic force microscopy on the order of 1 nm

We propose a standard stepped sample and specify a procedure for determining the step height for height-scale calibration of atomic force microscopy (AFM) instruments on the order of sub-nm to nm. The stepped Si(lll) surface structure was confirmed to be the most appropriate for the standard sample by a series of round-robin measurements carried out by a group comprising AFM instrument manufacturers and user organizations. By specifying a standard measurement procedure, the mean standard deviation of the step heights is decreased by 50%. It is also confirmed that the measured Si step height is accurate to +/-5%, which is consistent with the accuracy obtained for higher step standard samples. A prototype common data processing software program containing the algorithm of the specified procedure was used to allow direct comparison of the untreated measurement data from each organization. (C) 1996 American Vacuum Society.