Multiscale modeling of Schottky-barrier MOSFETs with disilicide source/drain contacts: Role of contacts in the carrier injection

Abstract

We report on a multiscale approach for the simulation of electrical characteristics of metal disilicide based Schottky-barrier metal oxide semiconductor field-effect transistors (SB-MOSFETs). Atomistic tight-binding method and nonequilibrium Green's function formalism are combined to calculate the propagation of charge carriers in the metal and the charge distribution at the $M{\mathrm{Si}}_{2}(111)∕\mathrm{Si}(111)$ and $M{\mathrm{Si}}_{2}(111)∕\mathrm{Si}(100)$ (with $M=\mathrm{Ni}$, Co, and Fe) contacts. Quantum transmission coefficients at the interfaces are then computed accounting for energy and momentum conservation, and are further used as input parameters for a compact model of SB-MOSFET current-voltage simulations. In the quest for nanodevice performance optimization, this approach allows unveiling the role of different materials in configurations relevant for heterostructure nanowires.