Patterned growth of arrays of SWNTs is achieved at the full-wafer scale. According to an example embodiment of the present invention, the chemistry of CH.sub.4 CVD has been discovered to be sensitive to the concentration of H.sub.2, leading to three regimes of growth conditions. The three regimes are identified for particular growth conditions and a regime that facilitates carbon nanotube growth while inhibiting pyrolysis is identified and used during CVD growth of the nanotubes. This approach is also useful for CVD synthesis of other nanomaterials. In this manner, patterned growth of carbon nanotubes is facilitated while inhibiting undesirable conditions, making nanotube orientation control and device integration possible on a large scale.