Lithography-free control of the position of single-walled carbon nanotubes on a substrate by focused ion beam induced deposition of catalyst and chemical vapor deposition

We introduce a novel nanofabrication technique to directly deposit catalyst pads for the chemical vapor deposition synthesis of single-walled carbon nanotubes (SWCNTs) at any desired position on a substrate by focused ion beam (FIB) induced deposition of silicon oxide thin films from the metalorganic precursor tetraethyl orthosilicate (TEOS). A high resolution in the positioning of the SWCNTs is naturally achieved as the imaging and deposition by the FIB are conducted concurrently in situ at the same selected point on the substrate. This technique has substantial advantages over the current state-of-the-art methods that are based on complex and multistep lithography processes.