C. R. Iordanescu, D. Tenciu, I. D. Feraru, A. Kiss, M. Bercu, D. Savastru, R. Notonier, C. E. A. Grigorescu, Structure and Morphology of Cu-oxides films derived from PLD processes, Dig. J. Nanomater Bios., 6/2 (2011) 863 – 868.

Title: Structure and Morphology of Cu-oxides films derived from PLD processes

Abstract:Copper oxides were prepared by thermal oxidation of copper PLD films:I) in air at 260 degrees C ii) in oxygen atmosphere at 300 degrees C (P(O2)=6x10(-3) Torr) and 700 degrees C (P(O2)=1.5x10(-4) Torr) respectively; iii) deposition of copper oxides with a pulsed laser from a Cu target at 700 degrees C (P(O2)=1.5x10(-4) Torr). Silicon wafers were used for substrates. The oxides' properties related to the oxidation temperature have been investigated by FTIR, micro-Raman spectroscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy. The films oxidized at lower temperatures show copper excess and also the presence of Cu(2)O(3). Thermal oxidation of PLD Cu films at 700 degrees C in oxygen and Cu-oxides films grown from a Cu target at T(s)=700 degrees C yield a mixture of CuO and Cu(2)O in the terminal surface of the samples as revealed by Raman spectroscopy measurements. The sample grown through ablation of Cu in oxygen at 1.5x 10(-4) Torr exhibits well defined Cu(2)O crystallites on top of a smooth CuO film, as shown by SEM imaging. Their sizes range between 1 mu m and 5 mu m and their shapes are typical for Cu(2)O.

Key words: Thin-Films; Copper; Deposition