Microstructure of Molybdenum Disilicide-Silicon Carbide Nanocomposite Thin Films

Composite thin films of molybdenum disilicide‐silicon carbide (MoSi2‐SiC) have been deposited via rf magnetron sputtering onto molybdenum substrates. An intermediate layer was deposited in the presence of nitrogen gas and evaluated as a potential diffusion barrier layer. The composite films have been characterized using X‐ray diffractometry, scanning electron microscopy, transmission electron microscopy, and Auger electron spectroscopy. The as‐deposited films were amorphous but crystallized into nanometer‐sized grains after annealing under vacuum at 1000°C for 30 min. There was a significant amount of interdiffusion between the film and substrate, which resulted in the formation of subsilicides such as Mo5Si3 and MoSi3, as well as Mo2C. The films that were deposited via reactive sputtering in a nitrogen ambient were amorphous in both the as‐deposited and annealed conditions. Significantly fewer second phases were detected with the presence of the intermediate layer, which suggests the potential use of the nitrided (MoSixNyCz) layer as a high‐temperature diffusion barrier layer for the silicon and carbon.