  A simple process for chemical vapor deposition of ultra SD single wall carbon
nanotubes has been developed. In this process, an iron nitrate nonahydrate
solution in isopropyl alcohol with a concentration of 400 ug/mlit was used to
catalyze nanoparticles formation on an oxidized silicon wafer. The oxide on the
substrate was made of a thick layer of wet oxide sandwiched between tow thin
layers of dry oxide. The process results in semiconducting single-walled carbon
nanotubes (SWNTs) with diameter of less than 0.7nm and more than 1ev band gap
energy, which are amongst the smallest diameters of SWNTs ever reported.
