Fabrication of suspended single-walled carbon nanotubes via a direct lithographic route

We report a fabrication method of suspended SWNTs between SiO₂ pillars via a direct lithographic route using a simple mixture of catalyst precursor and conventional electron beam resist. The catalytic electron beam resist (Cat-ER) plays roles as both catalyst and ER for growth and alignment of CNTs, respectively. Since the Cat-ER pattern can be utilized as an etch mask to fabricate the pillar structure, the suspended nanotubes are compatibly obtained with current lithographic processes. The suspended nanotubes are characterized to be single-walled by intensity mapping of a radial breathing mode in two dimensions with resonant Raman spectroscopy.