Abstract Submitted to the NANOTUBE'02 Workshop:

Plasma-enhanced chemical vapour deposition (PECVD) [1,2] is a versatile technique for growing vertically-aligned multiwalled carbon nanotubes/fibers directly on substrates. The lithographic requirements necessary to produce individual vertically standing nanofibers were investigated and we found that a high percentage (>88%) of single nanofibers, with a high degree of height and diameter uniformity, were nucleated when the dimension of the patterned catalyst was 300nm and below. A 100% yield of individual nanofibers (~50nm in diameter) was achieved with patterned catalyst dimension of 100nm. The dc electrical characteristics of individually contacted nanofibers were performed. It was found that each nanofiber could carry currents of about 200-2,000mA, before peeling of the outer shells of the nanofiber and successive drops in current carrying capability were observed. The field emission characteristics of individual nanofibers were also investigated and it was found that each nanofiber could emit useful currents of 10-20mA before failure. The discrepancy in maximum current between field emission and direct contact measurements are discussed with particular emphasis placed on possible failure/limiting mechanisms which occur under field emission. This work was funded by the European Commission projects NANOLITH and CANVAD.

[1] Z.F. Ren et al, Science 282,1105(1998); Appl. Phys. Lett. 75,1086(1999).
[2] V.I. Merkulov et al, Appl. Phys. Lett. 76,3555(2000).