Numerical study of the plasma chemistry for an inductively coupled plasma used for the synthesis of carbon nanotubes

Carbon nanotubes (CNTs) are gaining increasing interest, due to their unique physical, chemical and electronic properties, giving rise to a variety of (potential) applications. Plasma enhanced chemical vapour deposition (PECVD) has become a very promising technology for the direct synthesis of vertically aligned CNTs. In this presentation, a hybrid model, called the hybrid plasma equipment model (HPEM), is used to describe the plasma chemistry in an inductively coupled plasma, operating in a gas mixture of CH$_{4}$ with either H$_{2}$ or NH$_{3}$, as typically used for carbon nanotube (CNT) growth. Two-dimensional profiles of power density, electron temperature and density, gas temperature, and densities of some plasma species are plotted and analyzed. Besides, the fluxes of the various plasma species towards the substrate (where the CNTs can be grown), as well as the decomposition rates of the feedstock gases (CH$_{4}$, NH$_{3}$ and H$_{2})$, are calculated as a function of the CH$_{4}$ fraction in both gas mixtures. Finally, the influence of O$_{2}$ addition to CH$_{4}$/H$_{2}$ mixture on the plasma chemistry will be discussed and analyzed.