Ion-Beam-Assisted Deposition of MoS2 and Other Low-Friction Films
Interim rept. Jun 1988-Jun 1992
NAVAL RESEARCH LAB WASHINGTON DC
Pagination or Media Count:
Vacuum-deposited films of molybdenum disulfide MoS2 are effective as solid lubricants. Ion-beam-assisted deposition, which employs ion beam sputtering with an assist beam impinging on the growing film, has been investigated as a means of preparing low-friction high endurance coatings. The apparatus used and some of the techniques involved are described. Ion source operating parameters were optimized and the assist beam ion flux was quantified and found to follow a power-law relationship with beam power. The best way to produce MoS2 films was found to be cosputtering from separate Mo and S targets with deposition rates adjusted to obtain the desired stoichiometry. Deposition rates were found to also follow a power-law relationship with beam power, and formulae are given for predicting them, the ratio of assist ions to film atoms, and the effect of assist beam sputtering on film thickness. Inverse formulae are given for determining process parameters needed to achieve a selected film thickness and composition. A composite target for simultaneous Mo and S sputtering was developed. Deposition rates were determined for other metals W, N1, Co, Cu, and Pb. Formulae relating target-to-substrate distance to deposition rate are given.
- Physical Chemistry