Rotating-compensator multichannel ellipsometry: Applications for real time Stokes vector spectroscopy of thin film growth

Abstract

A multichannel spectroscopic ellipsometer based on the rotating-compensator principle was developed and applied to measure the time evolution of spectra (1.5–4.0 eV) in the normalized Stokes vector of the light beam reflected from the surface of a growing film. With this instrument, a time resolution of 32 ms for full spectra is possible. Several advantages of the rotating-compensator multichannel ellipsometer design over the simpler rotating-polarizer design are demonstrated here. These include the ability to: (i) determine the sign of the p-s wave phase-shift difference Δ, (ii) obtain accurate Δ values for low ellipticity polarization states, and (iii) deduce spectra in the degree of polarization of the light beam reflected from the sample. We have demonstrated the use of the latter spectra to characterize instrument errors such as stray light inside the spectrograph attached to the multichannel detector. The degree of polarization of the reflected beam has also been applied to characterize the time evolution of light scattering during the nucleation of thin film diamond by plasma-enhanced chemical vapor deposition, as well as the time evolution of thickness nonuniformities over the probed area of the growing diamond film. In this article, a detailed description of calibration and data reduction for the new instrument is provided. Future applications of this instrument are expected for real time characterization of film growth and etching on patterned surfaces for microelectronics and on thick transparent substrates for large area displays and photovoltaics.

Ion implantation induced disorder in single‐crystal and sputter‐deposited polycrystalline CdTe characterized by ellipsometry and backscattering spectrometry

“…, and E 2 [~5.1 eV]) using a rotating-compensator multichannel ellipsometer similar to that developed to study Si:H-based solar cells [6][7][8].…”

Variable-wavelength frequency-domain terahertz ellipsometry

“…Ellipsometry is therefore much less sensitive to nonidealities of the measurement system than intensity-normalized measurement techniques. [17][18][19][20] Ellipsometry in the terahertz frequency domain, however, is still in its infancy and experimental reports are scarce. [21][22][23][24][25][26] Nagashima and Hangyo 21 demonstrated the first ellipsometry setup operating in the terahertz frequency range.…”

Spectroscopic ellipsometry studies of In2S3 top window and Mo back contacts in chalcopyrite photovoltaics technology

“…A rotating-compensator multichannel spectroscopic ellipsometer was used having a potential range from 0.75 to 6.5 eV. Instruments of this design are described in detail elsewhere [4,5].…”