Multi-scale simulations of a Mo/n⁺–GaAs Schottky contact for nano-scale III–V MOSFETs

Abstract

Multi-scale modelling of the electron transport via a metal-semiconductor interface is carried out by coupling ab initio calculations with three-dimensional finite element ensemble Monte Carlo simulations. The results for the studied Mo/GaAs structure show that the metal's effect on the electronic properties of the semiconductor varies with the distance from the interface. Introducing this variation into Monte Carlo simulations strongly impacts the resultant transport characteristics of the system. We find that, in the case of an atomically abrupt interface, the variation in the electronic properties is on a large enough scale that treating the interface as abrupt in transport simulations is invalid. In particular, the band gap narrowing near the interface lowers the interface resistivity by more than one order of magnitude with respect to that calculated for the idealized Schottky contact: from 2.1×10 −8 to 4.7×10 −10 cm 2 . The dependence of the electron effective mass from the distance to the interface also plays an important role bringing the resistivity to 7.9×10 −10 cm 2 .

Atomistic study of an ideal metal/thermoelectric contact: The full-Heusler/half-Heusler interface

“…The HH local band gap renormalization near the interface (see Fig. 5a)) does not appear significant enough to warrant the consideration of a correspondingly position-dependent effective mass [34]. iii) We finally extend the band bending results to the doped case characterized by uniform background doping N d .…”

Narrowing of band gap at source/drain contact scheme of nanoscale InAs–nMOS

“…A 2×2×1 Monkhorst-Pack k-point set was used for the calculation with a cut-off of 500 eV. The density of states (DOS) for the semiconductor segment of the structure was projected on the atomic layers of In and As [4] Fig. 2.…”

“…In addition to the high carrier mobility, they exhibit a high injection velocity resulting in reduced power dissipation at low voltage operations [3]. In this work, we present a multi-scale simulation study of a nano-scale contact combining density functional theory (DFT) calculations with solutions of 1D Poisson-Schrödinger (1DPS) equation aiming to understand a relation among contact resistance and band structure at the interface [4] relevant to the future of sub-10 nm technology [5,6].…”

The Current Crowding Effect in ZnO Nanowires with a Metal Contact

“…Unlike microscale contacts, where the ability to select between Ohmic and Schottky behavior is performed by selecting a metal with appropriate workfunction and semiconductor material properties, nanoscale contacts do not follow a bulk properties of the material [14,15]. The transport properties of the nanocontact will depend on the size and geometry of the contact but there is still no generalized understanding of these effects in the literature [5,16,17].…”