The present invention provides a method for forming a self-aligned Ni alloy silicide contact. The method of the present invention begins by first depositing a conductive Ni alloy with Pt and optionally at least one of the following metals Pd, Rh, Ti, V, Cr, Zr, Nb, Mo, Hf, Ta, W or Re over an entire semiconductor structure which includes at least one gate stack region. An oxygen diffusion barrier comprising, for example, Ti, TiN or W is deposited over the structure to prevent oxidation of the metals. An annealing step is then employed to cause formation of a NiSi, PtSi contact in regions in which the metals are in contact with silicon. The metal that is in direct contact with insulating material such as SiO2 and Si3N4 is not converted into a metal alloy silicide contact during the annealing step A. selective etching step is then performed to remove unreacted metal from the sidewalls of the spacers and trench isolation regions.