The effect of Ni and Ni(Pt) alloy with ~5 and 10 at. % Pt on the agglomeration and Ge out-diffusion in Nickel germanosilicide formed on Si₀.₇₅Ge₀.₂₅(100) has been studied. A remarkable improvement in the agglomeration behavior with increasing Pt atomic percentage is observed by sheet resistance measurements and scanning electron microscopy (SEM). In addition, x-ray diffraction (XRD) shows that only NiSiGe or Ni(Pt)SiGe phase exists from 400 to 800°C. However, Ge out-diffusion from the monogermanosilicide grains is obvious at 600°C and 700°C for Ni/SiGe and Ni(Pt)(Pt at.%~10%)/SiGe, respectively, evident by XRD and micro-Raman spectroscopy. The improved melting temperature of Ni(Pt)SiGe solution compared to that of NiSiGe is the likely reason of seeing better surface morphology and suppressing Ge out-diffusion of the germanosilicide grains observed. / Singapore-MIT Alliance (SMA)