Carbon nanotube crossed junction by two step dielectrophoresis.

The crossed junction formed between a multi walled carbon nanotube (MWCNT) and a bundle of single walled carbon nanotube (SWCNT) is investigated. The junction is fabricated by orthogonally assembling the MWCNT and SWCNT by a two-step dielectrophoresis process. The conventional dielectrophoresis method to self-assemble carbon nanotubes has been modified to be able to align single MWCNT and SWCNT at predefined location on a substrate. At room temperature, the junction has an ohmic behavior with junction resistance of about 500 KOmega or a conductance of 0.05 (e2/h). At 77 K, the onset of a Schottky-like behavior was observed. The resulting junction has an extremely tiny area of less than 20 nm2 and yet supports a current density of 10(7) A/cm2 at 1 V. The proposed fabrication technique is a convenient way to fabricate novel prototype devices to investigate material properties and new device architecture. Following further optimization, this cross-junction can be an interesting candidate for cross-bar like interconnects, with potential applications in dense logic and memory circuits.