Morphology and kinetics of the interaction between Ni90Ti10 alloy thin film and 6H-SiC single crystal

摘要

Morphology and kinetics of phase formation were investigated in Ni90Ti10 alloy thin film evaporated on a 6H-SiC single crystal. The study was carried out by Auger electron spectroscopy, x-ray diffraction, and analytical transmission electron microscopy. The interaction was found to begin at 450 degrees C with the formation of the Ni-rich silicide, Ni31Si12, on the interface. The silicide exhibited highly oriented growth. After annealing at 800 degrees C for 1/2 h, three layers were observed in the reaction zone. In the first layer the presence of Ni-rich silicide, Ni2Si, and of C precipitates was revealed. The second layer was composed mainly of TiC, the third, of Ni2Si. Kinetics of the Ni90Ti10/6H-SiC interaction were investigated in the temperature range 450-500 degrees C. The Ni31Si12 silicide was found to grow by a parabolic law with an activation energy similar to 1.3 eV/at. The growth process was assumed to be controlled by Ni diffusion through the silicide. An "incubation time" was found to exist when the interaction occurs at temperatures lower than 500 degrees C. References: 25