The fabrication of three-dimensional networks of carbon nanotubes with controlled orientation will be essential for building large-scale functional devices integrated with microelectronics circuits. We describe here our recent work on the controlled synthesis of vertically aligned carbon-nanotube patterns, grown under patterned metal layers on Si substrates by combining chemical-vapor deposition and conventional lithography. We show that metal patterns are lifted up by vertically aligned nanotubes during growth. This lift-up growth links the thin-film metal patterns and the Si substrate via nanotube assemblies, giving the possibility of creating nanotube architectures in three dimensions. The possible scenarios of the growth of aligned nanotube films leading to the lift up of the metal films are discussed.
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