SURFACE-ANALYSIS OF FILMS AND FILM SYSTEMS PRODUCED BY PULSED-LASER DEPOSITION

Ceramic films and film systems (ZrO2 films, ZrO2/Ti multilayers, and B N films) are deposited by pulsed laser deposition (PLD) and analyzed u sing X-ray photoelectron (XPS), Auger electron (AES), and micro-Raman spectroscopies. The electron spectroscopies are used to determine the film stoichiometry, the nature of the bonding, and to specify contamin ant species. The micro-Raman spectroscopy gives information on crystal structure, grain size, and mechanical stress within the films. In ZrO 2 films a stoichiometry is achieved within typically 5%, with only wea k dependencies on processing variables. The only contaminants are a sm all amount of water from the ambient gas and a carbonaceous surface la yer. Multilayers consisting of alternating ZrO2 and Ti layers exhibit a TiC contamination within the Ti layers. Depending on the processing variables, BN films may be nearly stoichiometric or may have significa nt, even dominant contaminations throughout the film from elemental B, B2O3, and/or a boron-oxynitride species. The first component is due t o the non-stoichiometric material removal from the target (N-depletion ) at low laser fluences, as confirmed by XPS measurements on irradiate d targets. The second and third arise from H2O in the ambient, and exh ibit a complex dependence on processing variables. Micro-Raman spectra show only amorphous or hexagonal-phase BN. Depending on the position on the substrate relative to the laser-induced vapour/plasma plume, th ere may be a particle deposition or mechanical stress within the films , as evidenced from large shifts (up to 15 cm(-1)) of the Raman spectr al peaks.