A method of growing single-walled carbon nanotubes. The method may include supplying at least one of an oxidant and an etchant into a vacuum chamber and supplying a source gas into the vacuum chamber to grow carbon nanotubes on a substrate in an oxidant or an etchant atmosphere. The carbon nanotubes may be grown in an H2O plasma atmosphere. The carbon nanotubes may be grown at a temperature less than 500° C.