There are many precise surface measurement methods. Of these methods, white-light interferometer is the powerful tool capable of profiling surfaces with resolution on the order of nanometer. This technique allows us to extract three-dimensional surface profile without 2π-ambiguity. However, there are many problems to be tackled to enable white-light interferometer to be a more-general tool for precision surface metrology. One of these problems, the phase change upon reflection from the target surface is the most serious problems. It induces measurement errors of several tens of nanometer.Nowadays many researches on white-light interferometer are continued to solve these problems.
This paper proposes Virtual White-light Scanning Interferometer. We simply call it VWSI. VWSI is a simulation program composed of many parameters which have influences on white-light interference fringe. Using VWSI, we predict a physical phenomenon related to white-light interferometer in detail. For example, we easily estimate the change of an interference fringe according to the N.A. of the objective lens or the shift of envelope peak position due to phase change on reflection according to materials. So VWSI is the powerful tool to analyze the influence on the interference fringe according to critical variables such as the N.A. of the objective lens, spectral distribution of source, and phase change on reflection in metals and so on.
