Progress towards traceable nanometric surface metrology

It is not straightforward to relate measurements of surface topography made by different instruments because of the different geometrical and physical interactions between the measuring probe and the specimen surface. Improved correlation can be achieved if conditions are chosen so that these interactions are weak and this choice is facilitated by use of the instrumental amplitude-wavelength map. In order to provide traceable metrology NPL is constructing a precise measurement facility for use with different measuring probes and is also developing a range of artefacts for calibration purposes.