Synthesis and characterization of cubic boron nitride films: Substrate bias and ion flux effects

Cubic boron nitride (c-BN) thin films have been synthesized by radio frequency (RF) magnetron sputtering using a hexagonal boron nitride (h-BN) target. In addition to the substrate bias, the distance between the target and the silicon substrate was found to have a significant effect on the formation and volume fraction of the cubic phase in boron nitride films. The increase in ion energy above a certain threshold, corresponding to a substrate bias of - 450 V, led to the reduction of the cubic phase content and produced a non-stoichiometric boron nitride structure characteristic of boron-boron bonding. © 2001 Elsevier Science B.V. All rights reserved.