Optical properties of epitaxial ZnO layers have been studied in the spectral region from 1.5 to 5.4 eV using four-zone null spectroscopic ellipsometry. An existing model dielectric function based on excitonic structure near direct band gap has been improved by including a high-energy absorption term. Surface layer, corresponding to the surface roughness, was found to be essential to fit the spectroellipsometric data obtained. Two kinds of samples have been studied: ZnO layers prepared on (0001) and (112̄0)-oriented sapphire substrates. The surfaces of the first ones were found to be more rough.

No abstract

Spectroscopic ellipsometry ͑SE͒ in the visible/near-UV spectral range is applied to monitor optical critical dimensions of quartz, Si, and Ta gratings, namely, the depth, linewidth, and period. To analyze the SE measurements, the rigorous coupled-wave theory is applied, whose implementation is described in detail, referred to as the Airy-like internal reflection series with the Fourier factorization rules taken into account. It is demonstrated that the Airy-like series implementation of the coupled-wave theory with the factorization rules provides fast convergence of both the simulated SE parameters and the extracted dimensions. The convergence properties are analyzed with respect to the maximum Fourier harmonics retained inside the periodic media and also with respect to the fineness of slicing imperfect Ta wires with paraboloidally curved edges.

No abstract

Study of the electronic and vibrational properties of poly(ethylene terephthalate) and poly(ethylene naphthalate) filmsStructural, optical, and electrical characterization of gadolinium oxide films deposited by low-pressure metalorganic chemical vapor depositionThe dielectric function spectra of low dielectric constant ͑low-k͒ materials have been determined using spectroscopic ellipsometry, near-normal incidence spectroscopic reflectometry, and Fourier transform infrared transmission spectrometry over a wide spectral range from 0.03 to 5.4 eV ͑230 nm to 40.5 m wavelength region͒. The electronic and ionic contributions to the overall static dielectric constant were determined for representative materials used in the semiconductor industry for interlayer dielectrics: ͑1͒ FLARE-organic spin-on polymer, ͑2͒ HOSP-spin-on hybrid organic-siloxane polymer from the Honeywell Electronic Materials Company, and ͑3͒ SiLKorganic dielectric resin from the Dow Chemical Company. The main contributions to the static dielectric constant of the low-k materials studied were found to be the electronic and ionic absorptions.