Instability effects on the dark conductivity (σDark) and photoconductivity (σphoto) of microcrystalline silicon films with different microstructures deposited on smooth and rough substrates, after exposure to different storage conditions have been investigated. Samples stored in vacuum are less affected by aging than films stored in air and sealed plastic bags filled with N2 gas. The aging is reversible after annealing at 450 K. Thin films deposited on smooth and rough substrates with the same thickness and silane concentrations (SC) during the same deposition run showed similar aging effects. Thick samples exhibited a decrease in σDark, while both decrease and increase in σDark occur in thin samples after aging. For each sample, σDark and σphoto presented the same type of aging, independent of thickness and type of substrate used. The applicability of the steady‐state photocarrier grating technique was successfully tested on the rough substrates. Light‐induced degradation studies confirm the dependence of the Staebler‐Wronski effect on the crystallinity of the material (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

The isothermal oxidation behaviour of a Ni25Cr model alloy was studied using specimens of different thicknesses at 1000uC in dry and wet N 2 -1%O 2 . The oxidation mechanisms were evaluated using thermogravimetry and SEM/electron backscatter diffraction analyses of oxide scale cross-sections. The oxidation rates decreased with increasing specimen thickness and increasing water vapour additions in the gas. The findings can be explained by considering the effect of H-defects and in-scale stress state on point defect concentrations in the chromia lattice.

The reactive ion etching (RIE) of the binary transition-metal oxides (TMOs) NiO, CuO and CoO, which are expected to be key materials of resistance random access memory (RRAMÔ), was investigated. We found that inductively coupled plasma using CHF 3 -based discharge, which is highly compatible with conventional semiconductor RIE, is effective for the TMOs studied here. Furthermore, device fabrication using Pt/CoO/Pt trilayers is carried out, and a large change in resistance, which is an essential functionality of RRAM, was successfully observed. This should be definite evidence of a successful RIE realized in the present device fabrication.

The isothermal oxidation behaviour of a Ni25Cr model alloy was studied employing the JuSie-methodology, i.e. using specimens of different thickness for each specific test gas composition at 1000°C in dry and wet N2-1%O2 as well as in Ar-7%H2O. The oxidation mechanisms were evaluated using thermo-gravimetry and SEM/EBSD analyses of oxide scale cross sections. The ion beam polished oxide cross-sections were analysed in terms of oxide grain growth and nucleation rates of new oxide at the oxide-gas interface. The findings can be explained by considering the effect of H-defects and in-scale stress state on point defect concentrations in the chromium sub-lattice.