Novel nickel silicide contact technology using selenium segregation for SOI N-FETs with silicon-carbon source/drain stressors

Abstract

We explore a novel silicide contact technology for effective Schottky barrier height ΦBn and contact resistance reduction, which is compatible with an advanced silicon-carbon (Si1 -xCx) source/drain (S/D) stressor technology. The new silicide contact technology incorporates selenium (Se) that is coimplanted with S/D dopants into the silicon-carbon S/D prior to nickel silicidation, leading to the segregation of Se at the NiSi:C/n-Si0.99C0.01 interface and the achievement of excellent ohmic contact characteristics. We demonstrate that the Se-coimplantation process contributes to a 23% drive current enhancement in a strained silicon-on-insulator n-MOSFET. The enhancement is attributed to the decrease of external series resistance which is primarily due to the reduction of silicide contact resistance. © 2008 IEEE.