Use of cylindrical artefacts for AFM vertical calibration

Scanning probe microscopes are widely used for the surface analysis of micro- and nano-devices. In particular, the blow-up of miniaturization calls for the fine and traceable characterization of micro- topographies with the highest resolutions. This is at the basis of an increasing demand for easy and fast calibration procedures for such instruments. A number of artefacts are available on the market, intended prevalently for the calibration of SPM horizontal and vertical axes, in terms of scaling factors, linearity and squareness. The present paper focuses, in particular, on vertical calibration. New cylindrical artefacts that offer advantages in terms of instrument control are presented here. In particular, we discuss the possibility of calibrating the instrument all over the scanned range in terms of first-, second- and third-order vertical calibration coefficients (respectively C-zz', C-zz'2 and C-zz'beta). Two artefacts with different diameters were measured and compared in the investigations.