Dilute NiPt alloy interactions with Si

The reaction between a dilute Ni95Pt5 alloy and [111]Si has been investigated as a function of the annealing temperature and time, and the film thickness. Contrary to the concentrate alloys the first phase formed is Ni2Si and the growth kinetics in the initial steps are similar to the case of pure Ni. Pt segregates in the alloy and its presence slows down the silicide growth rate suggesting that a new mechanism, namely the release of Ni from the alloy, is competing with the diffusion process in the silicide. In all the cases here considered NiSi starts to form only when an the Ni is reacted, indicating that the Pt never reaches high enough concentrations to inhibit the Ni2Si growth. The further evolution of the system is similar to the ones reported for bilayers and non-dilute alloys. The I-V characteristics measured after annealing give a barrier height of 0.70+/-0.01 eV.