Thermal stability of NiPt- and Pt-silicide contacts on SiGe source/drain

NiPt (10% Pt) and Pt were investigated as alternatives to Ni for contact formation to SiGe (20%) source/drain. The germanosilicide phase formation and morphology were studied by means of sheet resistance measurements, X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM) inspection. From isothermal anneals it is found that NiPt- and Pt-germanosilicide have better thermal stability compared to Ni-germanosilicide. Improved thermal stability is observed for Ni-, NiPt- and Pt-germanosilicide on B doped SiGe as compared to undoped SiGe. The degradation mechanism of NiPt- and Pt-germanosilicide films on SiGe is morphological degradation while the film is still in the mono-(germanosilicide) phase.