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 kinetic of the C49-C54 transition will be shown in detail. The transformation kinetic has been monitored by in situ sheet resistance measurements that, coupled to structural characterisation, allowed to evidence the presence of an intermediate phase before the C54 formation. The temperature of the C54 phase formation decreases with a Ta concentration of 4.5x1015 cm-2 and u-Raman images of partially transformed samples indicates that the density of C54 grains in presence of Ta is about one order of magnitude higher with respect to pure Ti/Si samples.