Formation of nickel silicides onto (100) silicon wafer surfaces using a thin platinum interlayer

In this work, Ni(Pt) silicides were obtained starting from Ni/Pt films deposited on (100) silicon substrate and subsequent annealing step at temperatures from 350 to 600°C for 120 seconds in a Rapid Thermal Processing (RTP) furnace. The deposition process of a Ni(30 nm)/Pt(1.5 nm) bilayer onto Si (100) was e-beam evaporation. The Ni(Pt) silicide films were characterized by Rutherford Backscattering (RBS) spectrometry, X-Ray Diffraction (XRD) analysis, Atomic Force Microscopy (AFM) and four-probe measurements. From these characterization techniques, it was obtained crystallographic phases (XRD), surface micro-roughness (AFM) and, Ni(Pt) silicide stoichiometry and thickness by using RUMP simulations of the RBS spectra. The nickel silicide stoichiometry resulted NiSi for RTP performed at temperatures higher than 400 °C during 120 s. Also, this processing condition led to NiSi surface with low values of Root Mean Square (RMS) micro-roughness (<1.4 nm). Platinum was observed to be distributed along the NiSi film. On the other hand, XRD analysis revealed NiSi phases even for temperatures higher than 400 °C and the silicide resistivity is the lowest at 500 C and progressively degrades for higher temperatures.