Structural, optical and electrical properties of nanocrystalline TiO2 -- HfO2 thin films
In the present work the properties of mixed HfxTi1-xO2 solid solution thin films in metal-oxide-semiconductor (MOS) configuration have been studied. Thin films, were grown on monocrystalline silicon substrates using the low pressure hot target reactive sputtering from the Ti:Hf mosaic target. From optical transmission measurements the 3.42 (eV) bandgap of the thin films has been estimated. Electrical characterization of the prepared MOS structures shows classical capacitance- and current-voltage behaviors indicating medium-k gate oxide properties with the low leakage current
Characterization of nanocrystalline TiO2–HfO2 thin films prepared by low pressure hot target reactive magnetron sputtering
Abstract Thin films of oxides were deposited by magnetron sputtering in reactive oxygen plasma from Ti–Hf mosaic target. The low pressure of reactive gas and appropriate power of plasma discharge during the deposition assumed pseudoepitaxial conditions of the layer growth. Thin films were characterized by means of X-Ray Diffraction (XRD), Atomic Force Microscopy (AFM), X-ray Photoelectron Spectroscopy (XPS) and optical transmission. On the basis of obtained results it was stated that the fabricated thin films were composed of the stoichiometric HfTiO 4 single phase with average size of grains in the range of tenth of nanometers. Optical absorption spectra, derived in a conventional way from optical transmission measurements, yielded the optical band gap of about 3.42 eV. The grain size has changed after annealing in the range of 30 to 40 nm.
Pioneer 10 Observations of the Ultraviolet Glow in the Vicinity of Jupiter
A two-channel ultraviolet photometer aboard Pioneer 10 has made several observations of the ultraviolet glow in the wavelength range from 170 to 1400 angstroms in the vicinity of Jupiter. Preliminary results indicate a Jovian hydrogen (1216 angstrom) glow with a brightness of about 1000 rayleighs and a helium (584 angstrom) glow with a brightness of about 10 to 20 rayleighs. In addition, Jupiter appears to have an extensive hydrogen torus surrounding it in the orbital plane of Io. The mean diameter of the torus is about equal to the diameter of the orbit of Io. Several observations of the Galilean satellites have also occurred but only a rather striking Io observation has been analyzed to date. If the observed Io glow is predominantly that of Lyman-α, the surface brightness is about 10,000 rayleighs.