Influence of windows on the phase error of interferometric surface topography of a wafer using wavelength scanning

Phase-calculation formula, involving a window and Fourier transform term, have been used for decades to profile the shape of sample surfaces. Windows can be designed using the phase-calculation polynomial theory to eliminate various types of phase errors. Here, we discuss the phase errors calculated by the phase-calculation formulas, comprising the windows and Fourier transform terms, by considering not only the linear error of the phase modulation but also the combined error between the higher harmonics and linear error of the phase modulation. The surface topography of a 4-inch wafer was also profiled using phase-calculation formulas for the various types of windows and a Fizeau-type interferometer. We also discuss the repeatability of the phase errors calculated using phase-calculation formulas.