Comparison of raised and Schottky source/drain MOSFETs using a novel tunneling contact model

Abstract

We present, for the first time, a physical contact tunneling model that is critical for studying the increasingly important contact behavior in future scaled CMOS. The tunneling processes are self-consistently treated with all current transport in the semiconductor. With this new model, we compared the performance of raised S/D and Schottky S/D MOSFETs. Both raised S/D and Schottky S/D MOSFETs can be designed to give good short-channel characteristics. Our analyses show that despite the lower sheet resistance of the Schottky S/D MOSFETs, contact, resistance could be large due to finite Schottky barrier height. A lower barrier height contact material should be used to minimize the contact resistance.

Multiscale modeling of silicon heterojunction solar cells

“…It is also important to note that a computational issue associated with using low doped layers in the ITO(n + )/a-Si:H(p) junction is that the non-local band to band tunneling model being used suffers from convergence issues when the layers are completely depleted. Previous simulation studies conducted by Kanevce et al [44,18] and Kirner et al [52] showed the importance of the tunneling mechanism at the ITO(n + )/a-Si:H(p) junction. Thus, we arrive at the conclusion that; 1) a high workfunction achieved by low doping in the ITO(n + ) layer will lead to reduced tunneling at the ITO(n + )/a-Si:H(p) interface which will result in an increased ρc, and 2) a low workfunction achieved by high doping in the ITO(n + ) layer will lead to increased tunneling current and thus a lower ρc .…”

Numerical Simulations of IBC Solar Cells Based on Poly-Si Carrier-Selective Passivating Contacts

“…The energy of carriers, the occupied and free states in both sides of the barrier, and the energy barrier are therefore crucial parameters. As described by Ieong et al [45], the tunneling for transport of electrons and holes is, therefore, related to the local generation rate G as follows:…”

“…where is the reduced Planck constant and ψ e (r) is the electrostatic potential in terms of potential barrier profile along the position r for electrons, and m e are the tunneling masses of electrons and holes. Technology computer-aided design (TCAD) Sentaurus considers a complex state-of-the-art model detailed in [45] and [52] to describe transport through heterointerfaces by tunneling. However, the purpose of this paper is to only identify parameters affecting the collection of carriers through tunneling oxide in poly-Si based CSCs.…”

“…Interestingly, r ox , m e , m h , E B e , and E Bh have an exponential impact on Γ(r ox ), which contribute to define the current behavior [34], [45], [52] through G e and G h . From this approach, m e , m h , E B e and E B h are the parameters inherent to the dielectric material used as tunneling oxide (uniform SiO 2 ), but r ox is related to device process.…”

A multi-scale model for mobile and localized electroluminescence in carbon nanotube field-effect transistors

“…The energy range in this example is taken to extend above the barrier from the conduction band edge at the CN-contact interface E c (0) to a maximum energy chosen to capture all significant carriers (E max = µ S + 20kT ). The tunneling current can be conveniently incorporated into our multi-scale model by representing it as a generation rate, as described in [13] and adapted as follows (the electron case is given as an example here, however only minor modifications are necessary to treat holes): transforming the continuity equation,…”