Fourier transform infrared synchrotron ellipsometry for studying the anisotropy of small organic samples.

An experimental setup for polarization-dependent and spectroscopic ellipsometric measurements was developed that utilizes the brilliance of synchrotron infrared radiation at the electron storage ring at BESSY II for investigations of small samples and sample areas. During commissioning of the beamline and the experimental setup, a 1 mm2 piece of a well-characterized polyimide film was studied to show the benefits of Fourier transform infrared (FT-IR) synchrotron ellipsometry. The band shapes are interpreted with respect to the anisotropic distribution of transition dipole moments within the film. In comparison to a globar source, the signal intensity has been improved by more than one order of magnitude for this example.

Instrumentation for FT-IR reflection spectroscopy with synchrotron radiation.

A versatile experimental set-up for infrared reflectance measurements with synchrotron radiation and its adaptation to a beamline is presented. Particular consideration is given to the collimation and the polarization of incident radiation. The performance is characterized with experimental results. Due to the high brilliance of the synchrotron radiation source, the irradiation of samples smaller than 1 mm(2) was found to be improved by more than one order of magnitude when compared to a globar.

Infrared ellipsometric view on monolayers: towards resolving structural details.

The optical constants in the infrared spectral range and the thickness of a surface layer are simultaneously determined by reflection based spectroscopic infrared ellipsometry. In the past experimental progress has been used to increase sensitivity with the aim to detect ever thinner layers. Reaching the monolayer limit by now, methodic efforts focus on revealing structural details such as anisotropy and lateral heterogeneity caused primarily by molecular orientational order. The basis of the method and present methodical approaches are outlined. Aspects of using synchrotron radiation for infrared ellipsometry and of setting up an infrared beamline are discussed.

Ellipsometric studies related to surface-enhanced infrared absorption.

Infrared ellipsometry has been applied to determine the refractive index n and the absorption index k as well as the thickness of metal island films causing surface enhanced infrared absorption (SEIRA). The results from numerous films prepared in several campaigns are presented. For films of a nominal thickness of 6 nm, k is found to range from 0 to 3, while n ranges from 5 to 8. Among these two optical constants a close correlation is observed. Layers suitable for SEIRA exhibit an unusual spectral feature whose origin is explained.

Combined NRA, channeling-RBS and FTIR ellipsometry analyses for the determination of the interface and bonding state of thin SiO(x) and SiN(x)O(y) layers.

The molecular ions O(+)(2) and NO(+) are im- planted at room temperature into single-crystal silicon with an energy of E=6 keV/atom at fluences ranging from 2.5x10(16) to 3.5x10(17) at/cm(2). The samples are processed by electron beam rapid thermal annealing at 1100 ( degrees )C for 15 s. The depth distributions of the implanted specimens ((18)O) are determined by nuclear reaction analyses using the reaction (18)O(p,alpha)(15)N. Channeling-RBS measurements are performed to obtain the interface structure between the implanted layer and the single-crystal Si substrate. The chemical bonding state of as-implanted and implanted-annealed specimens is observed by FTIR ellipsometry measurements.

Infrared refractive index of germanium-silicon alloy crystals.

The relationship between infrared refractive index and near-infrared, visible, and ultraviolet absorption spectra is examined. The long-wavelength limit and dispersion are determined as simple functions of composition. The computed results are compared with infrared ellipsometric measurements.