Contact resistance reduction technology using aluminum implant and segregation for strained p-FinFETs with silicongermanium source/drain

Abstract

We have demonstrated the introduction of an additional aluminum (Al) implant step in the fabrication of strained p-FinFETs with silicongermanium (SiGe) source/drain (S/D). Al is implanted into the p+-SiGe S/D region at energy of 10 keV and a dose of 2×1014 atoms/cm 2, followed by its segregation at the NiSiGe/p+-SiGe S/D interface during germanosilicidation. The presence of Al at this interface leads to lowering of the effective Schottky barrier height for hole conduction, which, in essence, lowers the S/D contact resistance RC. R C is a dominant component of the FinFET parasitic series resistance RSD, which is lowered by approximately 25% using this technology, correspondingly leading to a substantial increase in the saturation drive current. The novel Al-segregated NiSiGe/p+-SiGe S/D contact junction in p-FinFETs does not degrade short-channel effects or the NiSiGe film morphology. © 2010 IEEE.