Abstract
Advanced signal processing is required to make exact measurements with nanometer order accuracy. A complex-valued interference signal of a white-light scanning interferometer (WLSI) obtained from the detected real-valued interference signal through Fourier transform provides an accurate position of an object surface with an error less than 4 nm. Moreover, the sampling points of the interference signal of the WLSI detected with a camera are corrected with the measured scanning positions which are obtained from an interference signal detected by using an optical band-pass filter. This correction method provides more accurate surface profiles with an error less than 2 nm. In experiments a surface profile with a step shape of 3 μm-width is measured accurately.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have