COMPOSITION AND GROWTH MODE OF MOSX SPUTTERED FILMS

MoS(x) lubricating thin films were deposited by nonreactive, reactive, and low energy ion-assisted radio-frequency (rf) magnetron sputtering from a MoS2 target. Depending on the total and reactive gas pressures , the film composition ranges between MoS0.7 and MoS2.8. A low working pressure was found to have effects similar to those of low-energy ion irradiation. Films deposited at high pressure have (002) planes prefe rentially perpendicular to the substrate, whereas films deposited at l ow pressure or under low-energy ion irradiation have (002) mainly para llel to it. Parallel films are sulfur deficient (MoS1.2-1.4). Their gr owth is explained in terms of an increased reactivity of the basal sur faces, itself a consequence of the creation of surface defects due to ion irradiation. The films exhibit a lubricating character for all com positions above MoS1.2. The longest lifetime in ball-on-disk wear test was found for MoS1.5.