Parasitics-Aware Quantum Transport Simulation of Stacked Si Nanosheet LGAA-nFETs for Sub-2 nm Node RF Applications

This work presents a comprehensive quantum transport modeling and simulation framework to evaluate parasitic effects and radio frequency (RF) performance in stacked silicon (Si) nanosheet (NS) lateral gate-all-around (LGAA) nFETs targeting the sub-2 nm technology node. Leveraging the non-equilibrium Green's function (NEGF) method, the proposed framework integrates detailed modeling of parasitic resistances (<i>R</i>_para) and capacitances (<i>C</i>_para) to enable a holistic analysis of both intrinsic and extrinsic figures-of-merit, including transconductance (<i>g</i>_m), output conductance (<i>g</i>_d), cutoff frequency (<i>f</i>_T), and maximum oscillation frequency (<i>f</i>_max). The effects of nanosheet geometry, crystal orientations, and dual-<i>k</i> spacers on high-frequency performance are systematically investigated. The analysis reveals key design trade-offs, with optimized device configurations yielding <i>f</i>_T exceeding 400 GHz and <i>f</i>_max approaching 1.2 THz. These findings highlight the potential of stacked NS LGAA-nFETs for future millimeter-wave and terahertz applications, providing critical insights into parasitics management and quantum-transport-aware design strategies at advanced CMOS nodes.