Multiphysics Simulation of Self-Heating-Induced Thermal Stress Effects on Quantum Transport in Gate-All-Around Nanosheet Field Effect Transistors

Abstract

The effects of self-heating-induced thermal stress on the quantum transport in p-type gate-all-around (GAA) nanosheet field effect transistors (NSFETs) are theoretically investigated in this article. The 3-D multiphysics simulation is performed to study the effects of self-heating-induced thermal stress on quantum transport in p-type NSFET by self-consistently solving quantum transport equations, heat conduction equation, and solid mechanics equilibrium equation, wherein the quantum transport equations and heat conduction equation are coupled by heat generation rate calculated from the current spectrum of nonequilibrium Green’s function (NEGF) with consideration of phonon scattering. The simulation results show that thermal stress induces a variation of band structure and changes the density of states (DOS) and hole effective mass. The variation of DOS leads to the variation of hole density and valence subband profiles. The drain current can be increased or decreased due to the variation of DOS depending on the crystal orientation configuration of device channel material.