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 0.61to0.15eV 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.