Directed growth of carbon nanotubes utilizing plasma induced surface charging voltage

Abstract

In this work, we present a method for directed lateral growth of carbon nanotubes (CNTs) between electrodes on a substrate during an in-situ Radio Frequency - Plasma Enhanced Chemical Vapor Deposition (RF-PECVD) CNT growth process, by utilizing plasma induced charging inherent in a Radio Frequency (RF) plasma process. The die consists of a pair of electrodes on insulator with lithographically patterned iron (Fe) catalyst islands on the edges. One electrode is electrically connected to the substrate by a platinum (Pt) plug while the adjacent electrode is electrically isolated. CNT growth was performed using RF-PECVD. Due to spatial non-uniformity in the plasma, the electrodes charged up to a different DC voltage each during the plasma process, a phenomenon known as plasma induced charging. A self-generated electric field is thus established during the growth between the isolated electrode with respect to the adjacent electrode to direct the lateral growth of CNTs.