Robust Transition Metal Contacts for Aligned Carbon Nanotubes

Aligned carbon nanotubes (A-CNTs) are emerging as one of the most promising materials for next-generation nanoelectronics. However, achieving reliable ohmic contacts between A-CNTs and metals remains a critical challenge. In this study, we employ rapid thermal annealing (RTA) to facilitate the forma...

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Main Authors: Gang Huang, Junhong Wu, Haiou Li, Honggang Liu
Format: Article
Language:English
Published: MDPI AG 2025-05-01
Series:Nanomaterials
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Online Access:https://www.mdpi.com/2079-4991/15/10/736
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author Gang Huang
Junhong Wu
Haiou Li
Honggang Liu
author_facet Gang Huang
Junhong Wu
Haiou Li
Honggang Liu
author_sort Gang Huang
collection DOAJ
description Aligned carbon nanotubes (A-CNTs) are emerging as one of the most promising materials for next-generation nanoelectronics. However, achieving reliable ohmic contacts between A-CNTs and metals remains a critical challenge. In this study, we employ rapid thermal annealing (RTA) to facilitate the formation of transition metal carbides at the metal–CNT interface, significantly reducing contact resistance and enhancing stability. Using the transmission line method (TLM), we demonstrate that RTA reduces the contact resistance at the Ti/A-CNT interface from 112.26 k<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi mathvariant="normal">Ω</mi><mspace width="0.166667em"></mspace><mo>·</mo><mspace width="0.166667em"></mspace><mi mathvariant="normal">μ</mi></mrow></semantics></math></inline-formula>m to 1.57 k<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi mathvariant="normal">Ω</mi><mspace width="0.166667em"></mspace><mo>·</mo><mspace width="0.166667em"></mspace><mi mathvariant="normal">μ</mi></mrow></semantics></math></inline-formula>m and at the Ni/A-CNT interface from 81.72 k<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi mathvariant="normal">Ω</mi><mspace width="0.166667em"></mspace><mo>·</mo><mspace width="0.166667em"></mspace><mi mathvariant="normal">μ</mi></mrow></semantics></math></inline-formula>m to 1.17 k<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi mathvariant="normal">Ω</mi><mspace width="0.166667em"></mspace><mo>·</mo><mspace width="0.166667em"></mspace><mi mathvariant="normal">μ</mi></mrow></semantics></math></inline-formula>m, representing a reduction of over an order of magnitude. Moreover, the Schottky barrier heights (SBHs) for both the Ti/A-CNT and Ni/A-CNT interfaces decreases by approximately 50% after annealing. A comparative analysis with Pd/A-CNT contacts shows that Ti and Ni contacts exhibit superior reliability under harsh conditions. This work provides a viable solution for improving the electrical performance and reliability of CNT-based devices, offering a pathway toward the development of future CMOS technologies.
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spelling doaj-art-3a1f0e49204e47799e673b96fb4ebad42025-08-20T03:14:39ZengMDPI AGNanomaterials2079-49912025-05-01151073610.3390/nano15100736Robust Transition Metal Contacts for Aligned Carbon NanotubesGang Huang0Junhong Wu1Haiou Li2Honggang Liu3Guangxi Key Laboratory of Precision Navigation Technology and Application, Guilin University of Electronic Technology, Guilin 541004, ChinaSchool of Integrated Circuits, Beijing University of Posts and Telecommunications, Beijing 100876, ChinaGuangxi Key Laboratory of Precision Navigation Technology and Application, Guilin University of Electronic Technology, Guilin 541004, ChinaSchool of Integrated Circuits, Beijing University of Posts and Telecommunications, Beijing 100876, ChinaAligned carbon nanotubes (A-CNTs) are emerging as one of the most promising materials for next-generation nanoelectronics. However, achieving reliable ohmic contacts between A-CNTs and metals remains a critical challenge. In this study, we employ rapid thermal annealing (RTA) to facilitate the formation of transition metal carbides at the metal–CNT interface, significantly reducing contact resistance and enhancing stability. Using the transmission line method (TLM), we demonstrate that RTA reduces the contact resistance at the Ti/A-CNT interface from 112.26 k<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi mathvariant="normal">Ω</mi><mspace width="0.166667em"></mspace><mo>·</mo><mspace width="0.166667em"></mspace><mi mathvariant="normal">μ</mi></mrow></semantics></math></inline-formula>m to 1.57 k<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi mathvariant="normal">Ω</mi><mspace width="0.166667em"></mspace><mo>·</mo><mspace width="0.166667em"></mspace><mi mathvariant="normal">μ</mi></mrow></semantics></math></inline-formula>m and at the Ni/A-CNT interface from 81.72 k<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi mathvariant="normal">Ω</mi><mspace width="0.166667em"></mspace><mo>·</mo><mspace width="0.166667em"></mspace><mi mathvariant="normal">μ</mi></mrow></semantics></math></inline-formula>m to 1.17 k<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi mathvariant="normal">Ω</mi><mspace width="0.166667em"></mspace><mo>·</mo><mspace width="0.166667em"></mspace><mi mathvariant="normal">μ</mi></mrow></semantics></math></inline-formula>m, representing a reduction of over an order of magnitude. Moreover, the Schottky barrier heights (SBHs) for both the Ti/A-CNT and Ni/A-CNT interfaces decreases by approximately 50% after annealing. A comparative analysis with Pd/A-CNT contacts shows that Ti and Ni contacts exhibit superior reliability under harsh conditions. This work provides a viable solution for improving the electrical performance and reliability of CNT-based devices, offering a pathway toward the development of future CMOS technologies.https://www.mdpi.com/2079-4991/15/10/736transition metal carbidescontact resistancealigned carbon nanotuberapid thermal annealingSchottky barrier height
spellingShingle Gang Huang
Junhong Wu
Haiou Li
Honggang Liu
Robust Transition Metal Contacts for Aligned Carbon Nanotubes
Nanomaterials
transition metal carbides
contact resistance
aligned carbon nanotube
rapid thermal annealing
Schottky barrier height
title Robust Transition Metal Contacts for Aligned Carbon Nanotubes
title_full Robust Transition Metal Contacts for Aligned Carbon Nanotubes
title_fullStr Robust Transition Metal Contacts for Aligned Carbon Nanotubes
title_full_unstemmed Robust Transition Metal Contacts for Aligned Carbon Nanotubes
title_short Robust Transition Metal Contacts for Aligned Carbon Nanotubes
title_sort robust transition metal contacts for aligned carbon nanotubes
topic transition metal carbides
contact resistance
aligned carbon nanotube
rapid thermal annealing
Schottky barrier height
url https://www.mdpi.com/2079-4991/15/10/736
work_keys_str_mv AT ganghuang robusttransitionmetalcontactsforalignedcarbonnanotubes
AT junhongwu robusttransitionmetalcontactsforalignedcarbonnanotubes
AT haiouli robusttransitionmetalcontactsforalignedcarbonnanotubes
AT honggangliu robusttransitionmetalcontactsforalignedcarbonnanotubes