Calibration of stylus profilometers using standards calibrated by metrological SFMs

Abstract

A method for calibrating stylus profilometers on the basis of metrological scanning force microscopes (SFMs) is proposed. Two kinds of such calibrations are presented. First, step height standards set (feature height from 7 nm up to 1000 nm), calibrated by metrological SFMs with expanded measurement uncertainties (k = 2) of only 1 to 1.5 nm, are applied to calibrate the z-axis scaling factor of profilometers. Second, roughness standards (ISO 5436-1 type D1), calibrated by a metrological large range SFM, are used to achieve dynamic calibrations of profilometers. The proposed method significantly improves the performance of the calibrated profilometers. For instance, the expanded measurement uncertainty (k = 2) of a PTB profilometer is reduced from 11.52 nm to 6.26 nm on Pt (total height of profile), and 7.57 nm to 3.25 nm on D (depth of the groove) calibrations of a groove sample (wide groove with flat bottom, nominal Pt = 2.7 νm). © 2005 IOP Publishing Ltd.