Integration of Al segregated NiSiGe/SiGe source/drain contact technology in p-FinFETs for drive current enhancement

Abstract

This paper demonstrates the integration of a novel aluminum (Al) segregated NiSiGe/p+-SiGe S/D contact junction in strained trigate p-FinFETs for drive current enhancement. Al is introduced by ion implant into p +-SiGe S/D region followed by nickel deposition and germano-silicidation. Drive current enhancement of ∼25 % is achieved in p-FinFETs without any degradation of device short channel effects. Devices with and without Al implant show similar threshold voltage, drain induced barrier lowering and subthreshold swing. The drive current enhancement is attributed to the lowering of the effective Schottky barrier height of holes (ΦBeff p) for NiSiGe on SiGe from 0.53 eV to 0.12 eV with the low dose Al implant of 2×1014 atoms/cm2, leading to lowering of contact resistance at the NiSiGe/p+-SiGe S/D interface. Al present at the NiSiGe/p+-SiGe interface thins down the Schottky barrier width, which is responsible for the lowering of ΦBeff p.