Rapid measurement of large step heights using a microscopic white-light spectral interferometer

Abstract

A method for rapid measurement of large step heights is proposed. Owing to elimination of mechanical scanning processes, this method possesses a greatly reduced measurement time. The theory underlying the proposed method is described in detail. The single-shot spectral interferometric signal is recorded using a Linnik microscopic white-light spectral interferometer and phase information is retrieved using a windowed Fourier transform. The proposed method was used to measure a 10.083(±0.022) μm step height standard. The mean measured height and standard deviation obtained from ten measurements were 10.0827 μm and 2.1 nm, respectively, and the experimental results agreed well with the calibrated value.