Search

The deposition, synthesis and the properties of the various [Fe.sub.65][Co.sub.35] and [Fe.sub.9.5][Co.sub.90.5] soft magnetic films are discussed. The transition of the crystalline structure and the magnetic properties of the films are shown to be completely dependent on the carbon content of the films.

Fe65Co35 and Fe9.5Co90.5 thin films with carbon addition were deposited by reactive sputtering and investigated in terms of static and dynamic magnetic properties. The acetylene rate was adjusted in order to deposit nanocrystalline soft magnetic films, with a high saturation magnetization, a high resistivity, and a low coercivity. The transition of the crystalline structure to a nanocrystalline or amorphous arrangement-giving rise to soft magnetic properties-depended on the Fe/Co ratio and the C content. The lowest coercivity of 0.4 Oe was obtained for a Fe9.5Co90.5 film with 0.95% of C2H2, whereas a Fe65Co35 film with 0.75% of C2H2 exhibited a coercivity of 0.7 Oe. The microwave properties of the Fe65Co35 layers remained stable over this C2H2 content whereas the resonance frequency of the Fe9.5Co90.5 films decreased with the C2H2 /Ar ratio. A difference in the manner that the carbon was incorporated, depending on the Fe/Co ratio, may explain the observed magnetic properties. [ABSTRACT FROM AUTHOR]

Electrical and structural properties of metal-oxide-semiconductor capacitors having as dielectric nanoscopic LaAlO3 or HfAlOx. films deposited on nitrided or nonnitrided Si substrates were investigated. The electrical superiority of RuO2/HfAlOx/SiON/Si stacks was evidenced by a dielectric Constant of 19 and a leakage current density of 67 mA/cm2 at a gate voltage of - 1 V, for a capacitance equivalent to silicon oxide thickness of 1.1 nm. Morphology, composition, and structure of the stacks were accessed by X-ray diffraction and refiectometry, spectroscopic ellipsometry, X-ray photoelectron spectroscopy, and narrow resonant nuclear reaction profiling with isotopic substitution. In spite of presenting crystalline phases associated with HfO2, the HfAlOx. dielectric layers led to a smoother and thinner interfacial layer, improved by the thermal nitridation of the Si substrate prior to high-K deposition. This SiON-like interlayer thickness is self-limited even after postdeposition annealing owing to the formation of an effective diffusion barrier by the strong N-Si-N and N-Si-O-N bonds, which is also effective in preventing substrate oxidation. [ABSTRACT FROM AUTHOR]

Thermal stability, electrical and structural properties induced by nitrogen incorporation in lanthanum-based high-k dielectrics were investigated. Thermal growth of a thin silicon oxynitride previously to LaAlO3 deposition induced higher dielectric constant, lower equivalent oxide thickness, and better interfacial stability during post-deposition annealing of MOS structures. But it also degraded others electrical and structural properties such as leakage current and charges densities, and interfacial roughness. Deposition of LaAlON films, either by reactive sputtering in Ar/N2 plasma, or by thermal nitridation in ammonia of LaAlO3, reduced partially several thermal instabilities after post-deposition annealing in 18O2, such as metallic losses, silicon diffusion and substrate oxidation. [ABSTRACT FROM AUTHOR]

The influence of processing parameters on the electrical characteristics of RuO2/LaAlO3/Si metal-oxide-semiconductor structures was investigated. In particular, the sputtering regime during deposition of LaAlO3 on Si and the atmosphere used in the post-deposition annealing step were addressed by determining capacitance-voltage and gate current-voltage characteristics. These results were correlated with compositional information obtained by Rutherford backscattering spectrometry and nuclear reaction analysis. A post-deposition annealing step in oxygen at 600 °C resulted in better electrical characteristics of the final structure as compared to the same treatment performed in nitrogen. This result is explained by oxygen ability to heal oxygen vacancies in the LaAlO3 film, especially at the dielectric/semiconductor interface region. A thermalized sputtering regime during deposition of LaAlO3 on Si leads to capacitors with electrical characteristics superior to those deposited in ballistic regime. [ABSTRACT FROM AUTHOR]

The electrical characteristics of RuO2/HfAlO/SiON/Si(001) capacitors prepared by thermal nitridation of the Si substrate previously to HfAlO ultrathin film deposition were determined. A dielectric constant of 19 and a gate current density of 67 mA/cm2 for an equivalent oxide thickness of 1.1 nm have been determined, whereas non-nitrided capacitors gave substantially lower dielectric constant and higher gate current density. The structure and integrity of the stacks after thermal annealing were accessed by means of spectroscopic ellipsometry and x-ray reflectometry, indicating that thermal N incorporation into the gate dielectric stacks forms an effective diffusion barrier, leading to a smoother, SiO2-like interface. The HfAlO films grown on nitrided substrates were seen also to have lower porosity, percentage of voids, and density of oxygen vacancies. [ABSTRACT FROM AUTHOR]

LaAlO3 films were deposited on p-type Si(100) by sputtering from a LaAlO3 target. C×V characteristics were determined in nonannealed and O2-annealed capacitors having LaAlO3 films as dielectric and RuO2 as top electrode. Thermal annealing in O2 atmosphere reduced flat band voltage to acceptable values for advanced Si-based devices. 16O–18O isotopic substitution was characterized by Rutherford backscattering spectrometry and nuclear resonant reaction profiling. Chemical analysis of the films was accomplished by x-ray photoelectron spectroscopy. The electrical improvements observed after thermal annealing in O2 were attributed to the incorporation of oxygen from the gas phase, possibly healing oxygen vacancies in the films and providing mobile oxygen to the interface. [ABSTRACT FROM AUTHOR]

Twelve high schools in Japan (of which six are in Fukushima Prefecture), four in France, eight in Poland and two in Belarus cooperated in the measurement and comparison of individual external doses in 2014. In total 216 high-school students and teachers participated in the study. Each participant wore an electronic personal dosimeter 'D-shuttle' for two weeks, and kept a journal of his/her whereabouts and activities. The distributions of annual external doses estimated for each region overlap with each other, demonstrating that the personal external individual doses in locations where residence is currently allowed in Fukushima Prefecture and in Belarus are well within the range of estimated annual doses due to the terrestrial background radiation level of other regions/countries.