Tomographic study of atomic-scale redistribution of platinum during the silicidation of Ni_(0.95)Pt_(0.05)/Si(100) thin films

摘要

Atom-probe tomography was utilized to study the distribution of Pt after silicidation of a solid-solution Ni_(0.95)Pt_(0.05) 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 (Ni_(0.99)Pt_(0.01))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 (Ni_(0.99)Pt_(0.01))Si/Si(100) interface, which may be responsible for the increased resistance of (Ni_(0.99)Pt_(0.01))Si to agglomeration. The relative shift in work function between as-deposited and annealed states is greater for Ni(Pt)Si than for NiSi.