This paper presents a study of Cu diffusion at various temperatures in thin SiO 2 films. Film composition and diffusion products were analyzed using Secondary Ion Mass Spectroscopy, Rutherford Backscattering Spectrometry, X-ray Diffraction and Raman Spectroscopy methods. We found a strong dependence of the diffused Cu concentration, which varied between 0.8 at.% and 10-3 at. %, on the annealing temperature. X-ray diffraction and Raman studies revealed that Cu does not react with the SiO 2 network and remains in elemental form after diffusion. Programmable Metallization Cell (PMC) resistive memory cells were fabricated with these Cu-diffused SiO 2 films as the active elements and device performance is presented and discussed in the context of the materials characteristics.

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We have measured the optical absorption coefficient of liquid As,S, and As,Se, up to 900°C in a wide absorption range up to about 3 X lCPcm-'. We have developed an optical cell of our own design wirh a sample thickness of about 2000A. The optical gap obtained from thespectra decreases rapidly with increasing temperature, eventually becoming zero at about 950°C for liquid ArSe?. where the semiconductor-to-metal transition starts to occur.

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This is an author-produced, peer-reviewed version of this article. AbstractThe Raman spectra of Ge-S glasses in the Ge-rich region from Ge 33 to 46 % have been investigated in order to know the structural development of the network glasses. From the detailed curve fits, we have found that there is an unassigned peak at 410 cm -1 and it becomes larger with increasing Ge composition. To clarify the structural origin of the peak, we virtually constructed the atomic arrangement of the glassy state starting from the crystalline state through the liquid state and changed the composition gradually depleting the medium in sulfur. From the consideration of the structural modeling and the atomic orbital theory, we suggest that single Ge-S chain is a probable structural origin of the peak.