title: White-light ellipsometer with geometric phase shifter.
abstract: We describe a simple spectroscopic ellipsometer that uses a geometric phase shifter and a white-light source to generate a small number of phase-stepped intensities I(λ), which are recorded by a spectrometer. The ellipsometric angles ψ and Δ are easily calculated from these intensities at each wavelength simultaneously. We show that errors in Δ due to the nonideal behavior of the achromatic quarter-wave plate in the phase shifter can be made small by suitably adjusting the azimuth of the linearly polarized light incident on the sample. Two silicon dioxide films were measured with this instrument between 450 and 850 nm and yielded best fit film thicknesses of 1000.6±0.1 Å and 20.6±0.1 Å, in excellent agreement with those obtained using a commercial ellipsometer.
authors.affiliation: Department of Physics, University of Auckland, Auckland, New Zealand. l.watkins@auckland.ac.nz
authors.forename: Lionel R
authors.initials: LR
authors.lastname: Watkins
authors.forename: Maxime
authors.initials: M
authors.lastname: Derbois