Characterization of TiAlN films deposited by reactive pulsed laser ablation

We have deposited TiAlN films by using the reactive laser ablation technique. TiAl targets were ablated in low-pressure N-2 (0.1-10 Pa) atmosphere by 2 X 10(4) XeCl excimer laser pulses at the repetition rate of 10 Hz. The laser fluence at the target was set at 6 J/cm(2), corresponding to a power density of 0.2 GW/cm(2). The films were deposited on Si substrates at room temperature, placed at 40 mm from the target. Their characteristics were investigated by many different techniques. Scanning electron micrographs show that surfaces are plane without cracks or corrugations. From Rutherford backscattering spectra it results that the thickness vary from similar to 100 nm for films deposited at 0.1-0.5 Pa to 50 nm for the film deposited at 10 Pa. The man composition is close to TiAlN for the film deposited at 0.1 Pa and close to TiAlN2 for the film deposited at 0.5 Pa. X-Ray diffraction analysis points to an amorphous structure of the film deposited at the lowest pressure (0.1 Pa), while peaks of fee TiN and hexagonal Ti3Al2N2 appear in the spectra of the films deposited at higher N-2 pressures. The complex chemical bonding of the top surface layer of the films was studied by X-ray photoelectron spectroscopy. (C) 2000 Elsevier Science B.V. All rights reserved.