Towards an optimal contact metal for CNTFETs

Fediai A, Ryndyk DA, Seifert G, Mothes S, Claus M, Schroeter M, Cuniberti G (2016)

Publication Type: Journal article

Publication year: 2016

Journal

Nanoscale Royal Society of Chemistry

Book Volume: 8

Pages Range: 10240-10251

Journal Issue: 19

DOI: 10.1039/c6nr01012a

Abstract

Downscaling of the contact length Lc of a side-contacted carbon nanotube field-effect transistor (CNTFET) is challenging because of the rapidly increasing contact resistance as Lc falls below 20-50 nm. If in agreement with existing experimental results, theoretical work might answer the question, which metals yield the lowest CNT-metal contact resistance and what physical mechanisms govern the geometry dependence of the contact resistance. However, at the scale of 10 nm, parameter-free models of electron transport become computationally prohibitively expensive. In our work we used a dedicated combination of the Green function formalism and density functional theory to perform an overall ab initio simulation of extended CNT-metal contacts of an arbitrary length (including infinite), a previously not achievable level of simulations. We provide a systematic and comprehensive discussion of metal-CNT contact properties as a function of the metal type and the contact length. We have found and been able to explain very uncommon relations between chemical, physical and electrical properties observed in CNT-metal contacts. The calculated electrical characteristics are in reasonable quantitative agreement and exhibit similar trends as the latest experimental data in terms of: (i) contact resistance for Lc = ∞, (ii) scaling of contact resistance Rc(Lc); (iii) metal-defined polarity of a CNTFET. Our results can guide technology development and contact material selection for downscaling the length of side-contacts below 10 nm.

Involved external institutions

University of Science and Technology (AGH) / Akademia Górniczo-Hutnicza PL Poland (PL) Technische Universität Dresden DE Germany (DE)

How to cite

APA:

Fediai, A., Ryndyk, D.A., Seifert, G., Mothes, S., Claus, M., Schroeter, M., & Cuniberti, G. (2016). Towards an optimal contact metal for CNTFETs. Nanoscale, 8(19), 10240-10251. https://doi.org/10.1039/c6nr01012a

MLA:

Fediai, Artem, et al. "Towards an optimal contact metal for CNTFETs." Nanoscale 8.19 (2016): 10240-10251.

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