  We have developed a fabrication process for incorporating a gate electrode
into suspended single-walled carbon nanotube structures for scanning tunneling
spectroscopy studies. The nanotubes are synthesized by chemical vapor
deposition directly on a metal surface. The high temperature ~800 C involved in
the growth process poses challenging issues such as surface roughness and
integrity of the structure which are addressed in this work. We demonstrate the
effectiveness of the gate on the freestanding part of the nanotubes by
performing tunneling spectroscopy that reveals Coulomb blockade diamonds. Our
approach enables combined scanning tunneling microscopy and gated electron
transport investigations of carbon nanotubes.
