Impact of material properties and device architecture on the device performance for a gate all around nanowire tunneling FET. (10th November 2017)

• Record Type: Journal Article
• Authors: Singh, S K; Gupta, A; Yu, H W; Nagarajan, V; Anandan, D; Kakkerla, R K; Chang, E Y
• Is Part Of: Materials research express. Volume 4:Number 11(2017)
• Publication Date: 2017-11-10
• Subjects: band-to-band tunneling (BTBT) -- sub-threshold swing (SS) -- tunnel FET (TFET) -- interface trap charge (ITC); Materials science -- Research -- Periodicals; Materials science -- Periodicals; 620.11
• DOI: 10.1088/2053-1591/aa95f9
• Languages: English
• ISSNs: 2053-1591

Abstract

Abstract: This paper systematically investigates the impact of gate dielectric, channel dimensional profile and the interface trap charge density on a homojunction indium–arsenide (InAs) gate all around nanowire tunneling FET (HJ-GAA-TFET). Device models were calibrated against the experimental data and simulations were performed to investigate the underlying physics. Device on-off ( I on / I off ) ratio was considered as key figure-of-merit (FOM) to improve. It is observed that the off current ( I off ) is a weak function of dielectric constant, however, the on current ( I on ) increases from 1.51 × 10 −7 A µ m −1 to 1.79 × 10 −6 A µ m −1 as the dielectric constant increases from SiO2 to La2 O3 . It was also observed that as the diameter increases, both I on and I off increases. I on / I off ratio is independent for higher channel lengths but as the channel length is reduced below 30 nm, I off increases causing degradation in I on / I off ratio. Finally, the effect of interface traps was realised on the I on / I off ratio. Interface traps impact the flat-band voltage causing a shift in the device performance. It is observed that as the trap density increases, I off degrades rapidly by ~3 orders in magnitude.