Electron transport via a few-dopant cluster in the presence of counter-dopants in silicon nanowire transistors

Abstract

Electron transport through a few-donor cluster flanked by acceptors is studied by first-principles and semi-empirical simulations in gated Si-nanowire transistors with n + electrostatically-doped source/drain. Local density-of-states spectra are probed by electrical characteristics at room temperature for clarifying modifications induced by acceptor-atoms on the energy states of the few-donor cluster. It is found that acceptor-atoms located between the few-donor cluster and the leads mainly shift the cluster potential, introducing a minor distortion to its energy spectrum. The results change only weakly as the acceptor-atoms are moved towards the Si nanowire surface, and systematically depend on the number of acceptors.

Single-Charge Tunneling in Codoped Silicon Nanodevices

“…Such analyses have been carried out extensively for Si nanocrystals [ 52 , 53 , 54 ] mainly with the aim of demonstrating their applicability to enhancing photoluminescence (PL). Only recently, studies have started to explore the effects of different configurations of counter-dopants in nanowire transistors [ 55 ]. It is expected that research at such fundamental level can reveal exciting new physics arising from the atomic-level counterparts of the nanoscopic devices presented here, diodes and transistors.…”

Challenges and Progress in the Fabrication of Silicon Nanowire Tunnel Diodes

“…Further studies are necessary to understand, design and fabricate devices with higher yields and enhanced functionality. For such purpose, it will be necessary to include also first-principles simulations in treating the atomic-level interactions between donors and acceptors, as recently started for codoped nanowire transistors [26]. Such insights can provide guidelines for the fabrication, interpretation and physics that may emerge in atomic-level pn diodes.…”