White light interferometry for vertical artifact calibration

Abstract

In this paper we describe a traceable to the meter standard method to measure the height of an artifact used as a calibrator for observation instruments in nanotechnologies and nanosciences. The artifact is a grating specially manufactured so that its features (height, pitch, width, wall angles) are highly uniform across its area. A Linnik microscope designed for longitudinal (vertical) measurements using the principle of white light interferometry was used to determine the height of the grating. To insure the traceability of the measurements a laser source of known wavelength was used and the measurements obtained using white light were calibrated to it. The experimental data was statistically analyzed and the measurement precision was estimated to be in the range of nanometers. The data were compared with the results obtained using the TIC method with a Carl Zeiss microscope.