IEEE Transactions on Electron Devices · 2019 · 58 citations · 13 references
EngineeringComputer EngineeringElectrical EngineeringMicroelectronicsSemiconductor DevicesSemiconductor MaterialsDevice ScalingField-effect TransistorsIntegrated Circuit DesignMetal-oxide-semiconductor Field-effect TransistorsSemiconductor Device MaterialsShort-channel EffectsDevice VariabilityFin Field-effect TransistorsGate-all-around Transistor ScalingGate-all-around TransistorsLine RoughnessLine-edge RoughnessProcess Variation AnalysisThreshold Voltage
Nanosheet gate-all-around (GAA) field-effect transistor (NSFET) is a potential replacement for the FinFET at advanced technology nodes owing to better control of short-channel effects and higher drive current. Due to the increased complexity of the GAA stacked structure, new forms of process variability come into the picture, which are dominant over the conventional process variability such as metal gate granularity (MGG) and line edge roughness (LER) for FinFETs. In this article, we show one such process variability called as metal thickness variation (MTV). MTV causes WF variations on the gates of the GAA sheet transistor and results in a significant VT variability. The impact of MTV is studied using an analytical framework. We studied three variants of NSFETs and reported variability in terms of key device design parameters such as intersheet spacing and metal thicknesses. The results presented here help in designing the process flow for a type of NSFET to minimize the VT variability.
13
Stacked nanosheet gate-all-around transistor to enable scaling beyond FinFET
N. Loubet, Terence B. Hook, P. Montanini et al. · 2017 · 988 citations