An Expandable <inline-formula> <tex-math notation="TeX">${\rm ZnS}\hbox{-}{\rm SiO}_{2}$ </tex-math></inline-formula> Liner Stressor for N-Channel FinFETs

Abstract

We report the demonstration of a novel ${\rm ZnS}\hbox{-}{\rm SiO}_{2}$ liner stressor to enhance drive current in Si n-channel FinFETs (N-FinFETs). ${\rm ZnS}\hbox{-}{\rm SiO}_{2}$ expands during thermal anneal due to an increase in crystallite size. A ${\rm ZnS}\hbox{-}{\rm SiO}_{2}$ liner stressor wrapping around an N-FinFET can be expanded and made to exert high tensile stress in the N-FinFET channel for drive current enhancement. Saturation drain current enhancement of ${\sim}{26\%}$ and linear drain current enhancement of ${\sim}{48\%}$ were observed for FinFETs with ${\rm ZnS}\hbox{-}{\rm SiO}_{2}$ liner stressor compared with control FinFETs without ${\rm ZnS}\hbox{-}{\rm SiO}_{2}$ , with no compromise on short-channel effects. The drain current enhancement increases with decreasing gate length. This technology was realized in FinFETs with silicon–carbon source/drain stressors and Al-incorporated NiSi contacts. ${\rm ZnS}\hbox{-}{\rm SiO}_{2}$ liner stressor could be a strain engineering option for N-FinFETs at sub-20-nm technology nodes.