NI (PT) SI Thermal Stability Improvement by Carbon Implantation

The thermal stability of Ni(Pt)-silicides by carbon implantation was evaluated. The Ni(Pt)-silicide morphology and phase formation were studied by means of sheet resistance (Rs) measurements, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) inspection, energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) analysis. The substrate crystallinity, carbon implantation dose and energy and the anneal conditions determine the stability of the silicide. Platinum and carbon increase the phase stability of Ni-silicide at high temperatures by increasing the disilicide nucleation temperature. The dominant degradation mechanism is morphological degradation for the NiPtSi:C films whereas transition to the NiSi2 phase is the dominant degradation mechanism for NiSi:C films. As compared to carbon incorporation by epitaxial growth of Si:C, the carbon implant has the advantage of being a simple technique that can also be applied to pMOS devices.