Effects of high in-situ source/drain boron doping in p-FinFETs on physical and device performance characteristics

In this study, the effects of high in-situ boron (B) doping in embedded source/drain (S/D) silicon germanium (SiGe) stressor of p-channel Fin Field Effect Transistors (FinFETs) in a 14 nm technology node were investigated. The device results were correlated to physical characteristics of B doped S/D regions which were probed using Transmission Electron Microscopy (TEM), Electron Energy Loss Spectroscopy (EELS) and Low Energy Electron Induced X-ray Emission Spectroscopy (LEXES) on representative device structures. B doping was established to be around low-E20 atoms/cm3 range as measured by LEXES. Reduction in on-state resistance (RON) and an increase in drive current (ION) was observed with higher B doping in SiGe but physical constraints, especially B segregation offered manufacturable challenges. These observed results are expected to critically help in SiGe stressor based S/D junction optimization of advanced FinFET Complementary Metal-Oxide-Semiconductor (CMOS) devices.