Optical profilometer/interferometer with AFM:
The commercial optical profilometer from MicroProf® (FRT GmbH, http://www.frt-gmbh.com) is used for the measurement of the surface roughness and the localization and characterization of defects. It is mounted on a solid granite support plate with an active vibration damping system and placed in front of a laminar airflow system (class 5 ISO) for cleanroom-like conditions. The measurement system combines a small CCD camera for fast orientation with the optical profilometer based on a spectral reflection (chromatic aberration) of white light and an AFM in calibrated positions (1 µm precision). Surface profiles of flat as well as curved samples up to 20x20 cm2 size and 5 cm height difference are measured fast (100 x 100 pixels in about 1 minute) and non-destructively down to 2 µm lateral and 3 nm vertical resolution. Further zooms into localized defect areas down to 3 nm lateral resolution can be performed with the AFM with 34x34 µm2 scanning range.
Measurement principle of optical profilometer
Measurement principle of AFM
Few examples of study of surface of electrolpished niobium performed by means of the optical profiolometer and AFM:
