Multiscale modeling of silicon-nanowire-based Schottoky barrier FETs for the biosensor applications
D. Nozaki, F. Zörgiebel, J. Kunstmann , W. M. Weber, G. Cuniberti
Approximate Quantum-Methods: Advances, Challenges and Perspectives
2010.9.20-24; Bremen Center for Computational Materials Science
Over the last few decades, 1D semiconducting silicon-nanowires (SiNWs) have been widely investigated as potential building blocks for future electronic devices because of their excellent electrical performance compared with bulk silicon, small sizes, and controllable bottom-up fabrications . Many groups have demonstrated promising biosensor applications of SiNW-based field effect transistors (FETs) . Recently Weber et al. have reported dopant-free Shottky barrier (SB) FETs consisting of intrinsic SiNWs working as a channel and NiSi2 nanowires working as source and drain contacts with gate lengths down to sub-photolithographic values . Measurements of their transport characteristics have shown the highest on-current and on-conductance values recorded to date for intrinsic SiNW-FETs . These SiNW-based SB-FETs are also expected to provide promising platforms for biosensor applications. In this work, we have developed a multi-scaled theoretical framework for the study of biosensors consisting of the intrinsic SiNW-based SB-FETs and biomolecules (receptors) covering the surface of the SiNWs. The aim of our study is to investigate the changes in the current through the SB-FETs in response to the binding of the ligands to the bio-receptors attached on the surface of the SiNWs. For this purpose, we have combined two approaches in different scales: one is a classical 1D-tunneling problem at the Si/NiSi2 interfaces in SB-FETs and another is the calculation of the electrostatic perturbation due to the biomolecules (receptors) attached on the surface of the NWs in atomistic scale using density functional theory. As a first step, in order to understand the basic charge transport characteristics though the SiNWs, we have modeled pristine SiNW-based SB-FETs consisting of an intrinsic SiNW working as a channel and NiSi2 NWs working as source and drain without the biomolecules. We have calculated the electrostatic potential profiles across the Si/NiSi2 interfaces with different gate lengths and gate voltages. Then we analyzed the influence of the gate lengths and the gate voltages on the charge tunneling through the SB-FETs. In addition, we have analyzed how the length dependence of the conductance in the SiNW-SB-FETs relates with the Anderson localization regime .
 R. Rurali, Rev. Mod. Phys. 82, 427 (2010).
 Y. Cui, Z. Zhong, D. Wang, W. U. Wang, and C. M. Lieber, Nano Lett. 3, 149 (2003).
 W. M. Weber, L. Geelhaar, A. P. Graham, E. Unger, G. S. Duesberg, M. Liebau, W. Palmer, C. Cheze, H. Riechert, P. Lugli, and F. Kreupl, Nano Lett. 6, 2660 (2006).
 W. M. Weber, L. Geelhaar, E. Unger, C. Cheze, F. Kreupl, H. Riechert, and P. Lugli, Phys. Stat. Sol. (b) 244, 4170 (2007).
 C. Gomez-Navarro, P. J. de Pablo, J. Gomez-Herrero, B. Biel, F. J. Garcia-Vidal, A. Rubio, and F. Flores, Nature Materials 4, 534 (2005).
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last modified: 2017.10.23 Mo
Prof. Dr. Gianaurelio Cuniberti
Institute for Materials Science
visitors and courier address:
01062 Dresden, Germany