Vertically Aligned Carbon Nanotubes Formed Using dc PECVD as Switching Elements for Extreme Environment Space Electronics

Abstract

AbstractVertically aligned carbon nanotube (CNT) nano-electro-mechanical (NEM) switches are currently being investigated for their application in radiation-hard, high temperature space electronics. Carbon nanotubes are attractive for switching applications since electrostatically-actuated CNT switches have low actuation voltages and power requirements, while allowing GHz switching speeds that stem from the inherently high elastic modulus and low mass of the CNT. Our NEM structure consists of CNTs that are grown using dc plasma-enhanced (PE) chemical-vapor-deposition (CVD) for forming vertically aligned, rigid tubes. A gas mixture of acetylene and ammonia were used for tube growth at a total pressure of a few Torr and temperatures up to 700 °C. We have formed arrays of single, vertically aligned tubes directly on Si, which was enabled by this first report of an optical lithography approach used to generate isolated tubes compared to e-beam lithography that is conventionally used. Vertical NEM switch devices were formed where single, vertically aligned tubes were seen within deep trenches, in close proximity to conducting electrodes.