Structural and physical properties of molybdenum produced by hydrogen reduction of molybdenum hexafluoride

Investigated was the regularity of molybdenum deposition from the mixture of its hexafluoride with hydrogen at 50-1200 deg C and different compositions of the gas phase. A narrow interval of compositions of the initial gas mixture is showed to exist, which provides formation of dense deposits with the maximum grain size up to 80% of MoF6 utilization. The change of the gas phase composition brings about the grain size reduction. Temperature increase in molybdenum deposition process from 550 550 to 800 deg C is followed by grain increase. The most dense deposits have columnar structure. At temperatures higher than 800 deg C ans small concentrations of molybdenum hexafluoride in the gas phase the deposits density decreases which is connected with dendritic structure formation