Schottky-barrier height tuning of Ni and Pt germanide/n-Ge contacts using dopant segregation

A systematic study of the Schottky barrier lowering induced by dopant segregation during Ni and Pt germanidation is presented. Both investigated doping species, As and P, segregated at the germanide/Ge interface during germanidation due to the snowplow effect. The effective Schottky-barrier height at 0 K of NiGe/n-Ge reduced from 0.72 eV for diodes without ion implantation to 0.19 eV by As segregation and to 0.34 eV by P segregration. The Schottky barrier lowering is more effective in PtGe₂/n-Ge contacts, where the effective barrier reduces to 0.05 eV by As and to 0.07 eV by P segregation.