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Horizontal carbon nanotube interconnects for advanced integrated circuits.

Published online by Cambridge University Press:  17 July 2013

Jean Dijon
CEA LITEN DTNM, 17 rue des Martyrs, 38054 Grenoble cedex 9, France.
Nicolo Chiodarelli
CEA LITEN DTNM, 17 rue des Martyrs, 38054 Grenoble cedex 9, France.
Adeline Fournier
CEA LITEN DTNM, 17 rue des Martyrs, 38054 Grenoble cedex 9, France.
Hanako Okuno
CEA LITEN DTNM, 17 rue des Martyrs, 38054 Grenoble cedex 9, France.
Raphael Ramos
CEA LITEN DTNM, 17 rue des Martyrs, 38054 Grenoble cedex 9, France.
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Horizontal carbon nanotube (CNT) interconnects are fabricated using a novel integration scheme yielding record wall densities >1013 shell/cm2, i.e. close to the density required for implementation in advanced integrated circuits. The CNTs are grown vertically from individual via structure and subsequently flipped onto the horizontal wafer surface. Various electrode designs are then used to produce different geometries of metal-to-tube contact such as side contact or end contact. CNT lines - 50 to 100 nm wide and up to 20 µm long - are realized and electrically characterized. The sum of the contact resistances from both ends of the lines is close to 500 Ω for 100 nm diameter lines which leads to a specific contact resistance of 1.6 10-8 Ω.cm2 per tube. With the developed technology, post-annealing of the contact does not improve the resistance values. Both chromium and palladium are used as contact metal. While contact resistance is equivalent with the two metals, the resistance per unit length of the lines does change and is better with palladium. This dependence is explained using a tunnelling model which shows that statistics of individual tube-metal contact is required to properly model the electrical results. Direct experimental evidences showing that only a part of the CNTs in the bundle is electrically connected are also given. Our best line resistivity achieved is 1.6mΩ.cm which is among the best results published for horizontally aligned CNTs and the only one with a realistic geometry for future VLSI interconnects.

Copyright © Materials Research Society 2013 

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Wei, B.Q., Vajtal, R., Ajayan, P.MReliability and current carrying capacity of carbon nanotubes, ” Apl. Pys. Lett. Vol79 n°8 pp11721174 Aug 2001 CrossRefGoogle Scholar
McEuen, P.L., Fuhrer, M.S. and Park, H., “Single wall carbon nanotube electronic“, IEEE Trans. Nanotechnol. Vol.1, n°1, p.7885, Mar 2002.CrossRefGoogle Scholar
Li, H.J., Lu, W.G. et al. ., “Multichanel ballistic transport in multiwall carbon nanotubesP.R.L. Vol. 95 n°8, p. 086601, Aug 2005.CrossRefGoogle Scholar
Srivastava, N., Li, H., Kreupl, F. and Banerjee, K.On the applicability of Single wall carbon nanotubes as VLSI Interconnects”, IEEE Trans. Nanotechnol. Vol. 8 n°4, p.542559, July 2009.CrossRefGoogle Scholar
Awano, Y., Sato, S., Nihei, M. et al. .: Proceedings of the IEEE Vol: 98 n° 12, p 20152031, Dec 2010 CrossRef
International Technology Roadmap for Semiconductors 2011Interconnect
International Technology Roadmap for Semiconductors 2011ERM p32
Dijon, J., Fournier, A., Szkutnik, P.D., et al. ., “Carbon nanotubes for interconnects in future integrated circuits: the challenge of the density”, Diam. Relat. Mat. 19, 382–88,(2010).CrossRefGoogle Scholar
Chiodarelli, N, Richard, O, Bender, H, Heyns, M, De Gendt, S, Groeseneken, G, et al. . “Correlation between number of walls and diameter in multiwall carbon nanotubes grown by chemical vapor deposition”. Carbon 50, 17481752, (2012).CrossRefGoogle Scholar
Zhao, Y, Wei, J, Vajtai, R, Ajayan, PM, Barrera, EV, Nat. Sci. Rep. 1(83), 15, (2011)
Dijon, J, Okuno, H, Fayolle, M, Vo, T, Pontcharra, J, Acquaviva, D, et al. . “Ultra-high density carbon nanotube on Al-Cu for advanced vias”. Electron Devices Meeting (IEDM) Proceeding (San Francisco. USA): p. 33.4.1-33.4.4, (2010)
Chiodarelli, N., Fournier, A., Okuno, H., Dijon, J.Carbon Nanotubes Horizontal Interconnects with End-Bonded Contacts, Diameters down to 50nm and Lengths up to 20µm”, Accepted in Carbon
Reeves, GK, Harrison, HB. “Obtaining the specific contact resistance from transmission line model measurements”. IEEE Electron Device Lett; 3(5), 111113 (1982).CrossRefGoogle Scholar
Vo, T. T.; Poulain, C.; Dijon, J.; et al. . “An experimental method to determine the resistance of a vertically aligned carbon nanotube forest in contact with a conductive layerJ.A.P. 112, (4), 044901, (2012).Google Scholar
Kim, Y.L. ; et al. . “Highly aligned scalable platinum decorated single wall carbon nanotube arrays for nanoscale electrical interconnects”, ASC nano 3, 2818–26 (2009).CrossRefGoogle ScholarPubMed
Acquaviva, D., Arun, A., Esconjauregui, S., et al. ., ”Capacitive nanoelectromechanical switch based on suspended carbon nanotube array”, APL 97, 233508, (2010)Google Scholar
Seichepine, F., Salomon, S., Collet, M., et al. ., “A combination of capillary and dielectrophoresis-driven assembly methods for wafer scale integration of carbon-nanotube-based nanocarpets”, Nanotech 23, 095303, (2012).CrossRefGoogle ScholarPubMed
Tawfick, S., O’Brien, K. and Hart, A. J., “Flexible high-conductivity carbon nanotube interconnects made by rolling and printings”, Small 5, n°21, 2467–73,(2009).CrossRefGoogle Scholar
Fourdrinier, L., Le Poche, H., Chevalier, N., Mariolle, D., Rouvière, E.Electrical properties measurements on individual carbon nanofibers by scanning spreading resistance microscopyJ. Appl. Phys ,104, 114305, (2008)CrossRefGoogle Scholar
Simmons, J.G.Generalized formula for electrical tunnel effect between similar electrodes separated by a thin insulating filmJ.A.P 34(6):17931803, (1963)Google Scholar
Shan, B., Cho, K., “Ab initio study of schottky barriers at metal-nanotube contacts”, PRB 70, 233405, (2004)CrossRefGoogle Scholar
Franklin, A.D. and Chen, Z., Nature nano 5, 858–62, (2010).CrossRef
Leong, H. L., Gan, C. L., Made, R. I., Thompson, C. V., Pey, K. L., and Li, H. Y., Experimental characterization and modeling of the contact resistance of Cu–Cu bonded interconnects, J. A. P. 105, 033514, (2009).Google Scholar
Robinson, J.A., LaBella, M., et al. ., “Contacting Graphene”, APL 98, 053103, (2011).Google Scholar
Kim, S., Kulkarni, D.D. et al. ., “Fabrication of an ultralow resistance Ohmic contact to MWCNT-metal interconnect using graphitic carbon by electron beam induced deposition”, IEEE Trans. Nano. 11 n°6, 12301237, (2012).Google Scholar