Tomographic study of atomic-scale redistribution of platinum during the silicidation of Ni_0.95 Pt_0.05 /Si (100) thin films

Atom-probe tomography was utilized to study the distribution of Pt after silicidation of a solid-solution Ni0.95 Pt0.05 thin film on Si(100). Direct evidence of Pt short-circuit diffusion via grain boundaries, Harrison's type-B regime, is found after silicidation to form (Ni0.99 Pt0.01) Si. This underscores the importance of interfacial phenomena for stabilizing this low-resistivity phase, providing insights into the modification of NiSi texture, grain size, and morphology caused by Pt. Platinum segregates at the (Ni0.99 Pt0.01) Si/Si (100) interface, which may be responsible for the increased resistance of (Ni0.99 Pt0.01) Si to agglomeration. The relative shift in work function between as-deposited and annealed states is greater for Ni(Pt)Si than for NiSi. © 2009 American Institute of Physics.