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A new study investigates the influence of limited instrumental bandwidth on the accuracy of methods uses to determine the density of states from modulated photoconductivity and transient photoconductivity data.

Electron energy loss spectroscopy studies of the amorphous to crystalline transition in FeF3 were conducted. The time-resolved studies reveal that the coordination polyhedra in amorphous FeF3 were randomly arranged FeF6 octahedra which are retained in amorphous FeF3. The change in the d-band occupancy by one electron and the sensitivity of the ratio of Fe L3 and L2 edges to the charge state of the iron ion are clearly illustrated using electron energy loss spectroscopy.

A study on techniques to develop polycrystalline silicon-based thin-film transistors for higher-performance, active-matrix, liquid-crystal displays investigated the laser crystallization of hydrogenated amorphous silicon thin films grown on glass substrates using plasma-enhanced, chemical-vapor deposition. The structure of the resulting polycrystalline silicon films was investigated using atomic force microscopy and transmission electron microscopy. Results are discussed.

The impact of extended heat treatment on the metal induced lateral crystallization (MILC) rate of amorphous silicon (a-Si) is studied using transmission electron microscopy and orientation image microscopy. Results show that extended heat treatment reduces the MILC rate possibly due to the constantly changing state of the a-Si and decreasing Ni from the Ni covered area. MILC length also increased with the radii of the Ni disc patterns with the longest MILC lengths generated by straight-edged Ni patterns due to their infinite radii of curvature.

A study was conducted to analyze the amorphous phase of platinum dioxide films. Nanoindentation determinations were carried out to determine the hardness and Young modulus of the films deposited on fused silica. Results indicated that the interatomic coordinates of the precursor are intermediate of the crystalline phases. Findings also showed that the phase resulting from the amorphous form is unpredictable and depend on various effects such as film stress.

Research was conducted to examine the growth and composition of dual-plasma polymer-like amorphous carbon films using butane as a carbon precursor and different mixtures in the microwave plasma to vary the atomic hydrogen flux impinging on the growing film. The influence of rf power, H atom flux, substrate temperature and plasma treatment by layer-by-layer deposition was investigated. Results demonstrate that infrared ellipsometry combined with UV-visible optical studies and density calculations offer some insight in the microstructure of hydrogen-rich carbon films.

A study was conducted to examine the structure and electronic features of amorphous nitrogenated carbon films. The films were prepared in dual electron cyclotron resonance-radio frequency plasma. Fourier transform infrared spectroscopy spectra was recorded on a Nicolet 20SXC spectrometer. Results indicated an interrelationship between the microstructure and electronic organization of nitrogenated carbon films.

Research was conducted to examine silicon-containing amorphous hydrogenated carbon films by a plasma-enhanced chemical vapor deposition process using Raman and ellipsometry spectroscopies. The carbon films were deposited on a silicon substrate from a self-biased rf plasma-enhanced chemical vapor deposition process. Electron probe microanalysis measurements were carried out to quantitatively analyze the films' silicon content. Results showed that Si incorporation influences the formation of sp3 carbon.

A study was conducted to examine the effects of oxygen on the thermal stability of amorphous hydrogenated carbon films by annealing them at 520, 610, and 670 K in vacuum and in O2 flow. The films were deposited by microwave plasma from a solution of 10 sccm pure methane and 100 sccm hydrogen in an electron cyclotron resonance chemical vapor deposition system. Results indicated that the transformation for annealed samples in O2 gas flow is supported at low temperatures.

In situ thermal pulse annealing of amorphous substrate to effect amorphous-germanium thin film phase transformation showed a film microstructure dependent on annealing ambient and exposure time. Air annealing showed hillock growth mode, while vacuum annealing produced a shift from microgranular to dendritic grain growth. The results indicate the possibility of Ge film presence in supercooled semiconductive liquid condition prior to crystallization.

Investigation of the structure of sputtered and laser-deposited Fe/Ag and Fe/Nb multilayers reveals the presence of considerable variation in sharpness of interfaces, textures and critical bilayer thicknesses for sputter- and laser-deposited alloys. The investigation is performed using the x-ray diffraction technique. The differences occur primarily during the annealing process. The Fe/Nb multilayers exhibit thin amorphous interlayers before annealing. The Fe/Ag have uniform interfaces. After annealing the interlayers are distorted.

Amorphous hydrogenated carbon a-C:H films have attracted considerable research interest because of their wide applicability. A study was conducted to investigate the deposition rates of a-C:H films as a function of the substrate thickness in the low-frequency region of the electric field for high-pressure conditions. The contribution of the kinetic energy of ion bombardment to the formation of the film is also discussed.

A study was conducted to show that the crystallization temperature of Ni/a-Si can be minimized to 380 degrees C during the presence of an electric field. Raman spectroscopy was carried out to determine the structural and electrical features of the nickel-metal induced crystallization poly-silicon films. Results indicated that the structure of the poly-silicon crystallized in an electric field correlated with the thickness of the nickel layer on the a-Si.

Crystal grain nucleation in amorphous silicon (a-Si) films induced by thermal annealing and ion beam irradiation at high substrate temperatures is studied. It was observed that the preparation conditions of the starting a-Si matrix determined nucleation rates. Thermal nucleation showed that crystallization begins at temperatures over 560 degrees Centigrade while nucleation kinetics improved at temperatures between 450 and 580 degrees Centigrade during ion beam irradiation.

Research was conducted to examine the photoluminescence mechanism of photo- and electroluminescent amorphous silicon oxynitride films grown by plasma enhanced chemical vapor deposition. Rutherfold backscatterimg spectrometry determined the composition of the films which were monitored by the index of refraction with single-wavelength ellipsometry. Results indicate a complete picture of luminescence in the silicon oxynitride films.