Plasma enhanced chemical vapor deposition (PECVD) is a unique technique for growing
vertically-aligned multiwall carbon nanotubes (VA-MWNTs) at controllable tube densities. This
technique is of considerable importance for low temperature growth of VA-MWNTs at desired
locations. However, the graphitic order of these MWNTs is inferior to those grown by laser
ablation, arc discharge, and thermal CVD techniques. Previously, these VA-MWNTs were
grown by a one-plasma approach (DC, microwave etc), either for gas decomposition or substrate
biasing. Here, we describe a dual-RF plasma enhanced CVD (dual-RF-PECVD) technique that
offers unique capability for controlling the graphitic order and diameters of VA-MWNTs.