Considerations for efficient contact resistivity reduction via Fermi Level depinning - impact of MIS contacts on 10nm node nMOSFET DC characteristics

In the overwhelming majority of cases, current-voltage characteristics of metal-based contacts on semiconductors are non-linear around 0V even for degenerate interfacial doping levels. Any contact resistivity specification is therefore meaningless without the knowledge of the effective bias across the contact. For the first time, the efficiency of a dielectric insertion for contact resistance reduction was properly evaluated by solving the self-consistent case of voltage sharing for an aggressively scaled transistor flanked by two trench Metal/ Insulator/Semiconductor (MIS) contacts. We found that leveraging the Fermi Level depinning via optimized MIS contacts could lead to a +92% drive current (VGS=Vdd=0.7V) increase versus a Titanium liner-based silicidation-free approach.