Effects of band-tails on the subthreshold characteristics of nanowire band-to-band tunneling transistors
- 1 October 2011
- journal article
- Published by AIP Publishing in Journal of Applied Physics
- Vol. 110 (7)
- https://doi.org/10.1063/1.3642954
Abstract
High source doping is required to support the high electric fields necessary to provide sufficient drive currents in interband tunnel field effect transistors (TFETs). High doping is associated with band-tails in the density of states that decay exponentially into the bandgap with decay constants that can be comparable to the room temperature thermal energy kBT. This compromises the core operational principal of a TFET of a hard energy cut-off to the injected channel carrier distribution provided by the source valence band edge. If the band-tails are limited to the source region, they have minimal effect for short channels ≤10 nm, since the leakage current is dominated by direct, coherent tunneling through the channel. For longer 20 nm channels, source band-tails can double the inverse subthreshold slope but still leave it below the ideal 60 mV/decade value with on-off current ratios greater than 106 using a supply voltage of 0.4 V. Band-tails both in the source and channel are more detrimental for both 10 and 20 nm channels. On-off current ratios are reduced to ≥103 and ≥104 for the 10 nm and 20 nm channel devices, respectively.Keywords
This publication has 37 references indexed in Scilit:
- Analysis of InAs vertical and lateral band-to-band tunneling transistors: Leveraging vertical tunneling for improved performanceApplied Physics Letters, 2010
- Simulation of nanowire tunneling transistors: From the Wentzel–Kramers–Brillouin approximation to full-band phonon-assisted tunnelingJournal of Applied Physics, 2010
- Modeling of High-Performance p-Type III–V Heterojunction Tunnel FETsIEEE Electron Device Letters, 2010
- Drive Currents and Leakage Currents in InSb and InAs Nanowire and Carbon Nanotube Band-to-Band Tunneling FETsIEEE Electron Device Letters, 2009
- Performance analysis of InP nanowire band-to-band tunneling field-effect transistorsApplied Physics Letters, 2009
- Atomistic Full-Band Design Study of InAs Band-to-Band Tunneling Field-Effect TransistorsIEEE Electron Device Letters, 2009
- Toward Nanowire ElectronicsIEEE Transactions on Electron Devices, 2008
- Influence of phonon scattering on the performance of p-i-n band-to-band tunneling transistorsApplied Physics Letters, 2008
- Band-to-Band Tunneling in a Carbon Nanotube Metal-Oxide-Semiconductor Field-Effect Transistor Is Dominated by Phonon-Assisted TunnelingNano Letters, 2007
- Low-subthreshold-swing tunnel transistorsIEEE Electron Device Letters, 2006