An ion-assisted, high-rate, reactive and pulsed-DC magnetron sputtering technique was used to deposit boron carbon nitride (BN:C) films by sputtering a boron carbide (B4C) target in an argon and nitrogen plasma. Substrate bias and temperature were adjusted to grow BN:C films with a high c-BN content. FTIR, scanning and transmission electron microscopy (SEM, TEM) and Auger electron spectroscopy (AES) were used to characterize the phases, composition and surface morphology of the films. The BN:C films deposited exhibit h-BN, w-BN, c-BN and their mixed phases at various substrate bias and temperature values. The optimum conditions found to deposit BN:C films with 82% c-BN content were at a substrate bias of -250 V and a temperature of 250 degreesC. In addition, a novel multi-step deposition technique with variable substrate bias was exploited to obtain similar to 700-nm-thick, adherent films with 95% c-BN content.