title: A multi-subband Monte Carlo study on dominance of scattering mechanisms over carrier transport in sub-10-nm Si nanowire FETs.
abstract: Dominance of various scattering mechanisms in determination of the carrier mobility is examined for silicon (Si) nanowires of sub-10-nm cross-sections. With a focus on p-type channels, the steady-state hole mobility is studied with multi-subband Monte Carlo simulations to consider quantum effects in nanoscale channels. Electronic structures of gate-all-around nanowires are described with a 6-band k · p model. Channel bandstructures and electrostatics under gate biases are determined self-consistently with Schrödinger-Poisson simulations. Modeling results not only indicate that the hole mobility is severely degraded as channels have smaller cross-sections and are inverted more strongly but also confirm that the surface roughness scattering degrades the mobility more severely than the phonon scattering does. The surface roughness scattering affects carrier transport more strongly in narrower channels, showing ∼90 % dominance in determination of the mobility. At the same channel population, [110] channels suffer from the surface roughness scattering more severely than [100] channels do, due to the stronger corner effect and larger population of carriers residing near channel surfaces. With a sound theoretical framework coupled to the spatial distribution of channel carriers, this work may present a useful guideline for understanding hole transport in ultra-narrow Si nanowires.
authors.affiliation: National Institute of Supercomputing and Networking, Korea Institute of Science and Technology Information, Daejeon, 305-806, Republic of Korea. elec1020@kisti.re.kr.
authors.forename: Hoon
authors.initials: H
authors.lastname: Ryu
keywords: Hole mobility; Multi-subband Monte Carlo simulations; Scattering dominance; Schrödinger-Poisson; Si Nanowire
references.citation: Nano Lett. 2010 Dec 8;10(12):4913-9
references.pmid: 21058716
references.citation: Nanoscale. 2013 Sep 21;5(18):8666-74
references.pmid: 23897026
references.citation: J Phys Condens Matter. 2012 Apr 4;24(13):135302
references.pmid: 22392836
references.citation: Phys Rev B Condens Matter. 1996 Aug 15;54(8):5675-5683
references.pmid: 9986530
references.citation: Nano Lett. 2015 Jan 14;15(1):450-6
references.pmid: 25555203