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

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) mu m step height standard. The mean measured height and standard deviation obtained from ten measurements were 10.0827 mu m and 2.1 nm, respectively, and the experimental results agreed well with the calibrated value.