Formation of nickel silicides onto as-doped silicon using a thin Pt/Pd interlayer

Thermal stability of nickel silicide was reached using a thin Pt (1.5 nm)/Pd (3.0 nm) interlayer between As-doped silicon and nickel (30nm). A shallow contact structure was fabricated and characterized using Ni (Pt/Pd) silicides formed at temperature ranging from 350 to 800°C for 120s. The Ni (Pt/Pd) silicide films were characterized by Rutherford Backscattering (RBS) spectrometry, X-Ray Diffraction (XRD) analysis, Atomic Force Microscopy (AFM) and four probe measurements. From these techniques, crystallographic phases (XRD), surface and interface micro-roughness (AFM) and, silicide stoichiometry and thickness by using RUMP simulations of the RBS spectra were obtained. The nickel silicide structure resulted a mixture of several phases (Ni 2 Si, NiSi 2 , Ni 3 Si or Ni 31 Si 12 ) with an average stoichiometry NiSi for rapid thermal annealing at 600 °C for 120 s. Also, this processing led to silicide with low interface RMS roughness (<0.7nm) and low resistivity (25.7 μΩ.cm). I-V curves were extracted from silicided n + p diodes, resulting in low reverse current density of 220 nA/cm 2 and ideality factor of 1.3.