REACTIVE SPUTTER-DEPOSITION AND CHARACTERIZATION OF LEAD-OXIDE FILMS

Lead and lead oxide containing films have been deposited on various su bstrates by radio frequency sputtering of a lead target in pure argon and argon-oxygen discharges. The sputter-deposited films were characte rized by Rutherford backscattering spectroscopy, nuclear reaction anal yses, and the x-ray diffraction technique. The composition, deposition rate, and crystalline structure of films were investigated as functio ns of the oxygen content (1.5%-50%) in the gas phase and sputtering po wer (50-200 W). The O/Pb atom number ratio increased rapidly up to one as the oxygen content in the discharge was varied from 1.5% to 6%. Th e films deposited under these conditions were composed of metallic lea d, yellow orthorhombic beta-PbO and PbO1.57 phases in variable proport ions. Amorphous and noncataloged lead oxide phases were also formed fo r oxygen contents in the discharge higher than 6%. The effect of the c omposition of the deposited material on the residual stresses develope d in the films was determined and related to the morphology of films e xamined by scanning electron microscopy. The friction properties of le ad and lead oxide containing films deposited on stainless steel disks were determined by alumina ball-on-disk tribological tests conducted i n air at a sliding speed of 3 cm s(-1) under a load of 2 N. The fricti on coefficient was investigated as a function of the sliding distance, him thickness, and surface roughness of tribological disks and test t emperature. (C) 1996 American Vacuum Society.