Density functional tight binding modeling in the context of ultra-thin SOI MOSFETs

Abstract

We investigate the applicability of density functional tight binding (DFTB) theory [1][2], coupled to non-equilibrium Green functions (NEGF), for atomistic simulations of ultra-scaled electron devices, using the DFTB+ code [3][4]. In the context of ultra-thin silicon-on-insulator (SOI) transistors we adopt atomic models that include not only the Si channel, but also the interfacial SiO2, and look at the change of electronic, dielectric and transport properties as Si film thickness is reduced from 10 nm to less than 1 nm. We build on our previous reports [5][6], and draw a systematic comparison against a corresponding model that employs H-passivation of the channel, and against known experiment.