Formation and stability of Ni(Pt) silicide on(100)Si and (111)Si

The effect of a small amount of Pt (5 at.%) on the thermal stability of NiSi film on (100)Si and (111)Si has been investigated. Rutherford back scattering, Scanning Electron Microscopy, and X-ray diffraction have been used to study the formation, microstructure and orientation of the suicide. The addition of platinum results in increasing the disilicide nucleation temperature to 900°C and thus leads to a better stability of NiSi at high IC processing temperatures. The presence of Pt also induced a texture of the NiSi film both on (111)Si and (100)Si. The increase in thermal stability is explained in terms of nucleation controlled reaction concept and should open new possibilities for the use of NiSi in self aligned silicidation. The redistribution of Pt in the suicide is examined and explained in terms of kinetics and thermodynamics considerations. The addition of Pt also increases the temperature of agglomeration of NiSi.