Low-Contact-Resistivity Nickel Germanide Contacts on n+Ge with Phosphorus/Antimony Co-Doping and Schottky Barrier Height Lowering

We report a low specific contact resistivity of 5.5 x 10-7 Ωcm 2 in nickel germanide (NiGe) contacts on n+ Ge. Data fitting with the contact resistivity model by A.M. Roy et al. (2010) suggests SBH of ~0.44eV for NiGe and ~0.55eV for Al/Ti contacts. We correlate this SBH and specific contact resistivity reduction with the dopant segregation at the NiGe/Ge interface and confirm it by SIMS analysis.