Optical emission spectroscopy study for optimization of carbon nanotubes growth by a triode plasma chemical vapor deposition

We carried out the in situ analysis of chemical species for the growth of carbon nanotubes (CNTs), deposited by a triode plasma enhanced chemical vapor deposition with a C2H2 and NH3 mixture, using optical emission spectroscopy (OES). A positive mesh bias enhances the radical density, thus increasing the growth rate. The vertically aligned CNTs were grown at a 50% C2H2 flow rate ratio to NH3 and mesh bias voltage of +300 V, resulting from the increased CH radical density and the decreased H and CN radical density through the OES analysis