Modulation of NiGe/Ge Schottky barrier height by sulfur segregation during Ni germanidation

We have demonstrated wide-range modulation of Schottky barrier height (SBH) of NiGe/Ge(100) interfaces by using a valence mending adsorbate, sulfur, segregation during Ni germanidation. Implanted sulfur atoms, segregated during Ni germanidation, are expected to act as dangling bond terminator at the NiGe/Ge interface. The experimental results show that the strong Fermi level pinning feature of NiGe/Ge interfaces was alleviated, and SBH of NiGe/n-Ge(100) gradually decreased from 0.61 to 0.15 eV with an increase in the implanted sulfur dose. This method opens a way to realize Ge channel complementary metal-oxide-semiconductor field-effect transistors with metal source/drain. (c) 2006 American Institute of Physics.