Formation of 〈110〉 texture during nanocrystalline diamond growth: an X-ray diffraction study

Nanocrystalline diamond (NCD) films have been elaborated in both H2/CH4 and Ar/H2/CH4 microwave plasmas. Thorough microstructural investigations have been carried out by X-ray diffraction analysis. A strong 〈110〉 fibre texture along with a 〈112〉 component are quantitatively pointed out. A growth mechanism taking into account a high nucleation rate and twinning is proposed in order to describe this preferentially oriented growth. The main concept is the development of ballas-like particles composed of nanometric growing sectors elongated along the 〈110〉 axis. This simple model, which could be interpreted as a selective evolution model at nanometric scale, is able to describe all the experimental observations presented in this work.