X-RAY PHOTOELECTRON-SPECTROSCOPY STUDY OF EXCIMER-LASER TREATED ALUMINA FILMS

Amorphous alumina layers are deposited on a single crystal Si substrat e by a e-gun evaporation technique. These films are then thermally ann ealed in oxygen to be crystallized and, further, irradiated with an ex cimer laser beam. At each stage of the film preparation, an x-ray phot oelectron spectroscopy analysis is performed at the film surface and i n depth, upon ion beam grinding. Results give evidence for the formati on of an aluminosilicate upon thermal annealing of the film in oxygen. At the surface itself, this compound is observed to decompose upon ex cimer laser irradiation at energy densities exceeding 1.75 J/cm(2), gi ving rise to free Si atoms and SiO2, however with complete disappearan ce of Al atoms. Model photochemical reactions are proposed to explain such transformations. (C) 1998 American Institute of Physics.