Chemical vapour deposition of MoS2 coatings using the precursors MoCl5 andH2S

MoS2 lubricant coatings were synthesized by low-pressure chemical vapour de position (LPCVD) using a gas mixture of MoCl5, H2S and argon. A thermodynam ic analysis shows that the deposition of pure MoS2 can be expected over a w ide range of temperatures. Deposition experiments were performed using ceme nted carbide and silicon substrates. The influence of process parameters on the deposition rate, layer composition and structure of the molybdenum sul phide coatings was investigated. Pure MoS2 layers can be prepared at substr ate temperatures of 500 and 600 degrees C. The chlorine content increases r emarkably with decreasing substrate temperature due to the codeposition of ternary MoSxCly compounds. At a low n(0)(H2S)/n(0)(MoCl5) ratio in the inpu t gas, Mo2S3 is codeposited. Layers deposited at 300 degrees C art: amorpho us. Between 400 and 600 degrees C. crystalline layers of a different morpho logy and texture were obtained. TEM investigations show that a preferred or ientation of the (002) basal planes exists only for the first range of MoS2 film growth. (C) 1999 Elsevier Science S.A. All rights reserved.