Atomic Level Modeling of Extremely Thin Silicon-on-Insulator MOSFETs Including the Silicon Dioxide: Electronic Structure

Abstract

Ultimate scaling of Si MOSFETs leads to extremely thin and short channels, which are justifiably modeled at the atomic level. Currently, hydrogen passivation of the channel is used in device models, as a compromise between efficiency and accuracy. This paper advances the state of the art by adopting a density-functional tight-binding Hamiltonian, permitting the inclusion of the confining amorphous oxide explicitly in the simulation domain in a way similar to ab initio approaches. Band structure of silicon-on-insulator films of different thicknesses is studied with this method, showing good agreement with the experiment and revealing large quantitative differences in comparison with simulations of H-passivated Si film.