Effect of diamond films as bufferlayer on formation of cubic boron nitride films by chemical vapor deposition

摘要

Boron nitride films are produced by the reaction of diborane (B_2H_6) and ammonia (NH_3) in a mixture of hydrogen and argon using microwave plasma-assisted chemical vapor deposition. Some parameters as NH_3/B_2H_6 ratios, hydrogen addition, substrate-bias voltage and working pressure are modulated to obtain high c-BN content in the film. The influence of diamond films with various grain sizes as bufferlayer on the formation of c-BN is investigated. As-grown BN/diamond films are characterized by Fourier transform infrared spectra, X-ray diffraction patterns and scanning electron microscopy. The results indicate that the nature of diamond film affects the amount of c-BN in the BN layer. Nanocrystalline diamond film can promote the c-BN formation, resulting in the c-BN content up to 85%. Thick c-BN/diamond multilayer up to 5.5 μm in total thickness and with nearly pure c-BN content is synthesized.