Product Code: ICAL05_M704

Catalyst Deposition and Carbon Nanotubes Growth by Laser-Assisted Chemical
Authors:
J. Shi, University of Nebraska-Lincoln; Lincoln NE USA
K. Tan, University of Nebraska-Lincoln; Lincoln NE USA
X.W. Wang, University of Nebraska-Lincoln; Lincoln NE USA
Yongfeng Lu, University of Nebraska-Lincoln; Lincoln NE USA
Presented at ICALEO 2005

With the recent advances of the aligned growth of carbon nanotubes (CNTs), there are great interests in CNT based field-emission and MOS transistor applications. However, techniques of deposition of catalysts and growth of carbon nanotubes at desired position are still not fully developed. In this study, we will report a method for direct deposition of catalyst and synthesis of CNTs on silicon wafers and pre-defined electrodes at specified locations using laser-assisted chemical vapor deposition. Lasers employed for catalyst deposition include an argon ion laser (CW, 514.5 nm) and a pulsed KrF excimer laser (23ns, 248 nm). Cobalt carbonyl was used as the precursor of cobalt catalyst. The carbonyl vapor pressure was at around 1-4 Torr, which corresponds to the cobalt carbonyl saturation pressure. After deposition of catalyst, CO2 laser (CW 10.6 �m) was focused on the defined structures as the thermal source for the growth of carbon nanotubes. The carbon feedstock was methane and argon gas mixture. SEM and TEM microscopy characterizations were carried out for the morphology and structural characterization of CNTs.