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 investigated the diffusion products occurring after photodiffusion of Ag in GeS 2 films at room temperature and after annealing up to 430°C. Quantitative data regarding the host film composition and the amount of diffused silver has been gathered using Rutherford backscattering spectrometry. The structure of the glassy host and the changes appearing after silver photodiffusion and annealing are characterized using Raman spectroscopy. The crystalline diffusion products are depicted and their size calculated using X-ray diffraction. We have found that silver reacts with the host to form Ag 2 S and Ag 2 GeS 3 and this leads to formation of Ge-rich backbone and overall nanostructured heterogeneous medium. Annealing at temperatures close to the glass transition temperature affects the backbone and brings about the appearance of a new diffusion product -Ag 8 GeS 6 .

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We are reporting our results of Raman and X-ray diffraction (XRD) studies on amorphous Ge 46 S 54 thin films and the films after silver photodiffusion. Based on the Raman scattering studies, a structural model for amorphous Ge 46 S 54 is suggested including the formation of single Ge-S chains with a vibrational mode at 410 cm À1 . The result of XRD measurement indicates that there exists a medium-range order with about 6 Ǻ even at such Ge-rich composition. After the introduction of silver, the medium-range order is lost and there was a change in the diffraction curve indicative of the change in the local atomic order. The experimental results are explained in terms of our structural model, in connection with the application for fast switching memory devices.