Nanowire FET With Corner Spacer for High-Performance, Energy-Efficient Applications

Parasitic capacitance in nanoscale FETs is becoming a dominant component of the total device capacitance which degrades device and circuit performance. This problem is exacerbated with the introduction of multigate FETs such as FinFET and gate-all-around FETs. In this paper, we introduce the corner spacer design for gate-all-around nanowire FET to significantly decrease parasitic capacitance with negligible degradation in ON-current. We show that the parasitic capacitance of a well-engineered corner spacer in a nanowire FET can be reduced by over 80% compared to the device with full nitride spacers. Ring oscillator stage delay and energy consumption of the corner spacer design are lower than the full spacer by over 50% each. This paper shows the possibility of engineering the spacers as a performance booster to continue scaling.