Effect of gas composition on texture of diamond films

Abstract
Textured diamond films have been deposited on single‐crystal silicon substrates by microwave plasma‐enhanced chemical vapor deposition. Several unconventional gas mixtures (CO2–CH4, CO2–C2H6, and CO2–C2H4) were used in order to study the texturing formation within the diamond stability region in the C–O–H phase diagram. Optical emission spectroscopy was used to monitor the compositional dependence of the plasma emission. The obtained diamond films were characterized by scanning electron microscopy and x‐ray diffraction. Diamond films deposited with all the gas mixtures showed very similar surface morphologies and (100) texturing was achieved only within a very narrow compositional range. Finally, a correlation was found between texturing conditions and CH and C2 line intensities in the plasma emission spectra.