Influence of experiment parameters on the growth of cBN films by bias-assisted direct current jet plasma chemical vapor deposition

Boron nitride films were synthesized on silicon substrates by radio frequency-bias- assisted direct current jet chemical vapor deposition in Ar–N₂–BF₃–H₂ system. The formation and content of cBN phase were investigated by means of Fourier transform infrared spectroscopy, glancing-angle x-ray diffraction, and scanning electron microscopy. The influences of the experimental parameters, i.e., bias voltage, substrate temperature, and gas composition, on the cBN content in the deposited films were systematically studied, and an experimentally optimum window for the deposition of cBN films was observed. Under optimized conditions, a boron nitride film with cBN content higher than 85% was deposited and a growth rate of about 70 nm/min was achieved.