Epitaxially Defined FinFET: Variability Resistant and High-Performance Technology

Abstract

FinFET technology is prone to suffer from line edge roughness (LER)-based V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</sub> variation with scaling. It also lacks a simple implementation of multiple V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</sub> technology needed for power management. To address these challenges, in this paper we present an epitaxially defined FinFET (EDFinFET) as an alternate to FinFET architecture for nodes 15 nm and beyond. We show by statistical simulations that EDFinFET reduces overall V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</sub> variability with an 80% reduction in LER-based variability in comparison with FinFETs. We present dynamic threshold MOS (DTMOS) configuration of EDFinFET using the available body terminal to individual transistors. The DTMOS configuration reduces LER-based variability by 90% and overall variability by 59%. It also has excellent subthreshold slope (SS) and gives 43% higher I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ON</sub> compared with FinFETs. Meanwhile, EDFinFET shows poorer SS and lower I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ON</sub> than FinFET due to single gate control. However, it is capable of multiple V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</sub> , which leads to circuit level power optimization.