An NEGF-Based Comprehensive Analysis of Parasitic Effects in Stacked Nanosheet FETs at 1.5-nm Technology Node

Reducing parasitics is expected to be a major knob for the CMOS performance promotion of ultrascaled nanosheet (NS) FETs. This article presents a novel modeling and simulation framework for parasitics-aware incoherent quantum transport, comprehensively investigating the dc and analog/RF performance of the stacked NS-FETs at a 1.5-nm technology node. Utilizing the transmission line model (TLM), conformal mapping, and elliptical integral, analytical models of parasitic resistances and capacitances are established and implanted into the quantum transport simulator, facilitating accurate analysis of parasitic effects. Based on exhaustive performance evaluation, the effects of crystal orientation configuration, doping concentration, structural parameters, contact, and spacer materials are figured out to provide strategic guidance for the design of next-generation NS-FETs. Optimizing the NS crystal orientation, contact and spacer materials can demonstrate an up-to-30% improvement in the energy-delay product (EDP) and cutoff frequency
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