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 deter mining the step height for height-scale calibration of atomic force mi croscopy (AFM) instruments on the order of sub-nm to nm. The stepped S i(lll) surface structure was confirmed to be the most appropriate for the standard sample by a series of round-robin measurements carried ou t by a group comprising AFM instrument manufacturers and user organiza tions. By specifying a standard measurement procedure, the mean standa rd deviation of the step heights is decreased by 50%. It is also confi rmed that the measured Si step height is accurate to +/-5%, which is c onsistent with the accuracy obtained for higher step standard samples. A prototype common data processing software program containing the al gorithm of the specified procedure was used to allow direct comparison of the untreated measurement data from each organization. (C) 1996 Am erican Vacuum Society.