High-quality, faceted cubic boron nitride films grown by chemical vapor deposition

Thick cubic boron nitride (cBN) films showing clear crystal facetes were achieved by chemical vapor deposition. The films show the highest crystallinity of cBN films ever achieved from gas phase. Clear evidence for the growth via a chemical route is obtained. A growth mechanism is suggested, in which fluorine preferentially etches hBN and stabilizes the cBN suface. Ion bombardement of proper energy activates the cBN surface bonded with fluorine so as to enhance the bonding probability of nitrogen-containing species on the F-stabilized B (111) surface.