Simulation of “Ab Initio” Quantum Confinement Scattering in UTB MOSFETs Using Three-Dimensional Ensemble Monte Carlo

In this paper, we report a 3-D Monte Carlo (MC) simulation methodology that includes complex quantum confinement effects captured through the introduction of robust and efficient density gradient (DG) quantum corrections (QCs), which has been used to introduce “ab initio ” scattering from quantum confinement fluctuations in ultrathin body silicon-on-insulator metal-oxide-semiconductor field-effect transistors (MOSFETs) through the real space trajectories of the particles driven by the DG effective quantum potential and to study the enhanced current variability due to the corresponding transport variations. A “frozen field” approximation, where neither the field nor the QCs are updated, has been used to examine the dependence of mobility on silicon thickness in large self-averaging devices. This approximation, along with the MC simulations that are self-consistent with Poisson's equation, is applied to study the variability of on-current due to random body thickness fluctuations in thin-body MOSFETs at low and high drain biases.