Carbon nanotubes are one of the most intensely studied systems with potential applications in nanoelectronics. Due to their promising electronic properties and their high conductivity, strategies have to be developed to insert them into conventional devices and to pre-define their position within circuit layouts. The substrate supported growth of the tubes from patterned catalyst layers has been followed as a possible approach. However, the growth of carbon nanotubes requires demanding preparation conditions, e.g. high temperatures up to several 100 oC. These conditions might harm other device components or are seen as a serious problem for the assembly of electronic circuits on polymeric supports. We follow a recently reported route[1] to use small catalyst particles which are selectively heated by microwave irradiation. Experimental evidence for the selective heating could be obtained by using a sensitive self-assembled monolayer, that degrades upon the application of a high temperature. It could be demonstrated that only in the vicinity of the particles sufficiently high temperatures could be reached to locally destroy the layer. Other parts of the substrate remain almost unaffected by the microwave irradiation. Additional experiments have been performed to use these small metal particles as catalysts for the growth of carbon nanotubes in the presence of ethanol vapour. The successful growth of multiwall carbon nanotubes on (patterned) catalyst layers will be demonstrated. This approach holds promises for the site-selective growth of carbon nanotubes into pre-assembled device features at comparably mild preparation conditions.
[1] E.H. Hong et al. Adv. Funct. Mater. 2003, 13, 961.
|