The effect of metal-contacts on carbon nanotube for high frequency interconnects and devices
- Nano-Scale Transport Physics laboratory and DST/NRF Centre of Excellence in Strong Materials, University of the Witwatersrand, P. Bag 3, Wits 2050, Johannesburg (South Africa)
High frequency characterisation of platinum and tungsten contacts on individual multi-walled carbon nanotubes (MWNT) is performed from 10 MHz to 50 GHz. By measuring the scattering parameters of aligned individual MWNTs, we show that metal contacts enhance an inductive response due to the improved MWNT-electrode coupling reducing the capacitive effect. This behaviour is pronounced in the frequency below 10 GHz and strong for tungsten contacts. We explain the inductive response as a result of the interaction of stimulus current with the localized (or defects) states present at the contact region resulting in the current lagging behind the voltage. The results are further supported by direct current measurements that show tungsten to significantly increase carbon nanotube-electrode coupling. The immediate consequence is the reduction of the contact resistance, implying a reduction of electron tunnelling barrier from the electrode to the carbon nanotube.
- OSTI ID:
- 22299760
- Journal Information:
- AIP Advances, Vol. 4, Issue 8; Other Information: (c) 2014 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 2158-3226
- Country of Publication:
- United States
- Language:
- English
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