On the Performance of Single-Gated Ultrathin-Body SOI Schottky-Barrier MOSFETs

The authors study the dependence of the performance of silicon-on-insulator (SOI) Schottky-barrier (SB) MOSFETs on the SOI body thickness and show a performance improvement for decreasing SOI thickness. The inverse subthreshold slopes S extracted from the experiments are compared with simulations and an analytical approximation. Excellent agreement between experiment, simulation, and analytical approximation is found, which shows that S scales approximately as the square root of the gate oxide and the SOI thickness. In addition, the authors study the impact of the SOI thickness on the variation of the threshold voltage V-th of SOI SB-MOSFETs and find a non-monotonic behavior of V-th. The results show that to avoid large threshold voltage variations and achieve high-performance devices, the gate oxide thickness should be as small as possible, and the SOI thickness should be similar to 3 nm

Impact of the dimensionality on the performance of tunneling FETs: Bulk versus one-dimensional devices

The influence of the dimensionality on the performance of tunneling field-effect transistors is investigated with simulations. It is shown that in a three-dimensional tunneling FET it is possible to achieve inverse subthreshold slopes smaller than 60 mV/dec. However, there is a trade-off between high on-currents and small values for the subthreshold swing. Using a carbon nanotube tunneling FET as an example it is shown that in contrast to the 3D case, one-dimensional systems offer the possibility to combine a high on-state performance with steep inverse subthreshold slopes. (c) 2007 Elsevier Ltd. All rights reserved

Comparison of transport properties in carbon nanotube field-effect transistors with Schottky contacts and doped source/drain contacts

In this Letter, we present a simulation study of the electrical characteristics of ultimately scaled carbon nanotube field-effect transistors. Devices with Schottky contacts and doped source/drain contacts are compared. We show that for small bias devices with doped source/drain contacts exhibit a better on- as well as off-state compared to devices with Schottky contacts. Both device types, however, show a poor off-state for larger bias. We will discuss the relevant transport mechanisms involved and explain our observations. (C) 2004 Elsevier Ltd. All rights reserved

Physics of ultrathin-body silicon-on-insulator Schottky-barrier field-effect transistors

The effects of in vitro preconditioning protocols on the ultimate survival of myoblasts implanted in an in vivo tissue engineering chamber were examined. In vitro testing: L6 myoblasts were preconditioned by heat (42 °C; 1.5 h); hypoxia (<8% O(2); 1.5 h); or nitric oxide donors: S-nitroso-N-acetylpenicillamine (SNAP, 200 μM, 1.5 h) or 1-[N-(2-aminoethyl)-N-(2-aminoethyl)amino]-diazen-1-ium-1,2-diolate (DETA-NONOate, 500 μM, 7 h). Following a rest phase preconditioned cells were exposed to 24 h hypoxia, and demonstrated minimal overall cell loss, whilst controls (not preconditioned, but exposed to 24 h hypoxia) demonstrated a 44% cell loss. Phosphoimmunoblot analysis of pro-survival signaling pathways revealed significant activation of serine threonine kinase Akt with DETA-NONOate (p < 0.01) and heat preconditioning (p < 0.05). DETA-NONOate also activated ERK 1/2 signaling (p < 0.05). In vivo implantation: 100,000 preconditioned (heat, hypoxia, or DETA-NONOate) myoblasts were implanted in SCID mouse tissue engineering chambers. 100,000 (not preconditioned) myoblasts were implanted in control chambers. At 3 weeks, morphometric assessment of surviving myoblasts indicated myoblast percent volume (p = 0.012) and myoblasts/mm(2) (p = 0.0005) overall significantly increased in preconditioned myoblast chambers compared to control, with DETA-NONOate-preconditioned myoblasts demonstrating the greatest increase in survival (p = 0.007 and p = 0.001 respectively). DETA-NONOate therefore has potential therapeutic benefits to significantly improve survival of transplanted cells

Improved Carrier Injection in Ultrathin-Body SOI Schottky-Barrier MOSFETs

The impact of the gate oxide and the silicon-on-insulator (SOI) body thickness on the electrical performance of SOI Schottky-barrier (SB) MOSFETs with fully nickel silicided source and drain contacts is experimentally investigated. The subthreshold swing S is extracted from the experimental data and serves as a measure for the carrier injection through the Sills. It is shown that decreasing the gate oxide and body thickness allows to strongly increase the carrier injection and hence, a significantly improved ON-state of SB-MOSFETs can be obtained

Effective Schottky barrier lowering in silicon-on-insulator Schottky-barrier metal-oxide-semiconductor field-effect transistors using dopant segregation

We present an investigation of the use of dopant segregation in Schottky-barrier metal-oxide-semiconductor field-effect transistors on silicon-on-insulator. Experimental results on devices with fully nickel silicided source and drain contacts show that arsenic segregation during silicidation leads to strongly improved device characteristics due to a strong conduction/valence band bending at the contact interface induced by a very thin, highly doped silicon layer formed during the silicidation. With simulations, we study the effect of varying silicon-on-insulator and gate oxide thicknesses on the performance of Schottky-barrier devices with dopant segregation. It is shown that due to the improved electrostatic gate control, a combination of both ultrathin silicon bodies and gate oxides with dopant segregation yields even further improved device characteristics greatly relaxing the need for low Schottky barrier materials in order to realize high-performance Schottky-barrier transistors