Effect of a thin Ta layer on the C49-C54 transition

The effect of a thin Ta layer at the Ti/Si interface on the kinetics of the C49-C54 transition is reported. The transformation kinetics were monitored in detail by in situ sheet resistance measurements, which, coupled to structural characterisation, allowed us to evidence the presence of an intermediate phase before C54 formation. The temperature at which the C53 phase is formed decreases at a Ta concentration of 4.5 X 10(15) cm(-2). mu -Raman images of partially transformed samples indicates that the density of C54 grains in the presence of Ta is about one order of magnitude higher with respect to pure Ti/Si samples.