Step-By-Step Development of Vertically Aligned Carbon Nanotubes by Plasma-Enhanced Chemical Vapor Deposition

In this work, the growth process of self-sustained vertically aligned carbon nanotubes (VA-CNTs) is investigated in full: from bare Si wafers to fully grown VA-CNTs on 4″ wafers. Each developmental step, from supporting and catalyst layers’ depositions to CNT growth, is analyzed through X-ray diffraction, X-ray reflectivity, and scanning electron microscopy, respectively. The crystalline structure of the titanium nitride supporting layer is investigated through grazing incidence X-ray diffraction, while X-ray reflectivity provides information regarding the density, thickness, and roughness of the titanium nitride layer via extended Fourier analysis. Further, the nickel layers’ and CNTs’ morphologies are investigated by scanning electron microscopy.