Study of thermal diffusion between Al2O3 and Al thin films

Alumina and aluminum thin films were deposited by physical evaporation meth ods obtaining a set of five samples of Al2O3(130 nm)/Al(130 nm)/glass. Samp les were heat treated in vacuum between room temperature and 600 degrees C. After annealing, samples were characterized by means of Anger electron spe ctroscopy (AES), scanning electron microscopy (SEM), X-Ray diffraction (XRD ) and stylus profilometry. All samples present a fairly large amount of alu minum in the alumina layer, Samples heat-treated between room temperature a nd 400 degrees C show an interface roughness between layers, which obscures thermal diffusion, The diffusion coefficient at 500 degrees C, for metalli c aluminum is D = 1.5 x 10(-15) cm(2) s(-1). At a temperature of 600 degree s C the interface width between the deposited layers increases, resulting i n an uniform layer with all components mixed. (C) 1999 Elsevier Science B.V . All rights reserved.