Spectrally resolved phase-shifting interference microscopy: technique based on optical coherence tomography for profiling a transparent film on a patterned substrate.

Spectrally resolved white-light phase-shifting interference microscopy has been used for measurements of the thickness profile of a transparent thin-film layer deposited upon a patterned structure exhibiting steps and discontinuities. We describe a simple technique, using an approach based on spectrally resolved optical coherence tomography, that makes it possible to obtain directly a thickness profile along a line by inverse Fourier transformation of the complex spectral interference function.