Thermal stability of Co, Ni, Pt or Ru Schottky contacts on n-Si and defects introduced thereon during contacts fabrication using electron beam deposition

Abstract

When using Schottky barrier diodes (SBDs) on silicon (Si) to study the thermal stability of radiation-induced defects, point defects injection into the silicon substrate can occur at temperatures where silicidation occurs. These injected point defects can react with the radiation-induced defects and may lead to an incorrect picture of annealing studies of these defects. In order to overcome this problem, we have annealed (1) ruthenium (Ru), cobalt (Co), nickel (Ni) and platinum (Pt) SBDs to form stable silicides on phosphorus (P) doped Si and (2) have measured the electrical characteristics of defects introduced during diodes fabrication by electron beam deposition (EBD), using conventional and (high resolution) Laplace (L-) deep level transient spectroscopy (DLTS). A primary electron trap at 0.48 eV below the conduction band was observed after EBD processing of the contacts. Isochronal annealing of the SBDs at 350 °C, annealed-in defects 0.05, 0.09, 0.18 and 0.28 eV below the conduction band. All the EBD-induced defects were removed after annealing at 600 °C. Primary defect depth profile versus annealing temperature results are also presented in this study.