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Amorphous carbon films with sp3 bonded carbon fractions over 70% are deposited by pulsed laser deposition. However, the optical bandgap obtained from optical transmittance and spectroscopic ellipsometry analysis shows the values to be below 1.0 eV. A wide range of measurements such as electron energy loss spectroscopy, visible Raman, spectroscopic ellipsometry, optical transmittance, and electrical characterization are performed to elucidate the bonding configurations that dictate microstructural, optical and electrical properties, and their linkage to band structure changes. It is found that stress-induced electronic localized states play an important role in the physical properties of the films deposited. The optical bandgap is shown not to be a good measure of the electrical bandgap, especially for high electric field conduction in these tetrahedral amorphous carbon films. [ABSTRACT FROM AUTHOR]

In this study, we investigate the effect of the inclusion of nitrogen in amorphous carbon thin films deposited by pulsed laser deposition, which results in stress induced modifications to the band structure and the concomitant changes to the electronic transport properties. The microstructural changes due to nitrogen incorporation were examined using electron energy-loss spectroscopy and Raman scattering. The band structure was investigated using spectroscopic ellipsometry data in the range of 1.5–5 eV, which was fitted to the Tauc Lorentz model parametrization and optical transmittance measurements. The dielectric constant evaluated using optical techniques was compared to that obtained with electrical measurements, assuming a Poole-Frenkel type conduction process based on the best fits to data. The electrical conduction mechanism is discussed for both low and high electric fields, in the context of the shape of the band density of states. By relating a wide range of measurement techniques, a detailed relationship between the microstructure, and the optical and the electrical structures of a-CNx films is obtained. From these measurements, it was found that, primarily, the change in density of the film, with increasing nitrogen pressure, affects the band structure of the amorphous carbon nitride. This is due to the fact that the density affects the stress in the film, which also impacts the localized states in the band gap. These results are supported by density of states measurements using scanning tunneling spectroscopy. [ABSTRACT FROM AUTHOR]

Presents a study which reported the application of spectroscopic phase modulated ellipsometry to the study of both ultrafast and slow processes of the interaction of silane with thin films of palladium (Pd). Formation of palladium silicides by interaction of SiH[sub4] with Pd thin films; Details of an experiment on Pd; Microstructure of as-deposited Pd films; Description of the High SiH[sub4] fluxes.

Discusses a detailed in situ spectroellipsometry analysis of the nucleation and growth of μc-silicon (Si) films deposited on c-Si substrate. Preparation of the films; Formation of the surface roughness.

Presents an in situ study, by spectroellipsometry, of interfaces between amorphous silicon and silicon nitride. Nature of the interface between amorphous silicon and silicon nitride; Results of the study.

Investigates the metalorganic vapor deposition of a number of heterojunctions using reflectance anisotropy (RA). Characterization of the heterojunctions; Experimental details; RA observations of heterojunction growth.

Discusses the in situ reflectance anisotropy (RA) measurements of InAs (100) metalorganic chemical vapor deposition (MOCVD) growth under optimal growth conditions. Experimental details; Diagram of the RA system; Effects of the MOCVD reactor on the growth.

Investigates the growth of InAs on indium phosphide (InP) and InP on gallium arsenide using reflectance anisotropy (RA) measurements. Growth procedure; Details of the RA technique; Results; Discussion on the optical models; Insights on the growth process.

Presents information on in situ spectroellipsometric analysis of the nucleation and growth of hydrogenated amorphous silicon (Si). Use of plasma-enhanced chemical vapor deposition; Reason for the increase in surface roughness of silicon; Coalescence and bulk a-Si:hydrogren growth.