Nano-Metrology Between Necessity and Reality

Microscopes (optical, scanning probe, atomic force, WLI, SNOM, confocal) are being increasingly used as metrology tools in industrial applications, thus driving an increasing demand for accuracy in these instruments. Some properties commonly measured in nanotechnologies are feature spacing (pitch), feature height (or depth), feature width (critical dimension), and surface roughness. To achieve high accuracy in all these measurements, the scales of an instrument should be calibrated. A quasi-generalized confusion between resolution and accuracy makes researchers not habituated to measurement to use high resolution instruments in improper conditions and report results with too many significant (?!) digits. The last digit must be not the resolution but the one indicated by the uncertainty of measurement. As a rule for the commercial instruments used for observation in nanosciences and nanotechnologies, their intrinsic accuracy is not indicated, but only the resolution. Necessary commentaries regarding nanometrology are presented in this paper.