A multichannel spectroscopic ellipsometer based on the rotating-compensator principle was developed and applied to characterize nanocrystalline diamond thin film growth processes by plasma-enhanced chemical vapor deposition (PECVD). With the newly-designed instrument, a time resolution of 32 ms is possible for spectra (1.5approx4.0 eV) in the Stokes vector of the light beam reflected from the surface of the growing film. Several advantages of the rotating-compensator over the simpler rotating-polarizer multichannel ellipsometer design are demonstrated here for diamond thin film growth. These include the ability to: (i) resolve the sign ambiguity in the p-s wave phase-shift difference, triangle open, (ii) obtain accurate triangle open values for low ellipticity polarization states, and (iii) deduce spectra in the degree of polarization of the light beam reflected from the film/substrate. The degree of polarization has been applied to characterize the time evolution of light scattering during the nucleation of the diamond, as well as the time evolution of thickness non-uniformity over the probed area of the growing film. In this paper, a brief description of calibration and data reduction for the new instrument is also provided.
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