Preparation of c-BN films by using a two-stage deposition process

Cubic boron nitride (c-BN) films were deposited on Si(100) substrates with a conventional sputter device from an h-BN target in pure Ar discharge by u sing a two-stage deposition process. The preferentially oriented h-BN layer s were firstly deposited with radio frequency (r.f.) power of 600 W at the substrate negative bias voltage of 100 V for 10-15 min, and then followed b y the deposition of c-BN films with r.f, power of 400 W at different substr ate negative bias voltage ranging from 0 to 180 V for 150 min. The deposite d films were examined primarily by transmission Fourier transform infrared (FTIR) spectroscopy. The results indicate that the preferentially oriented h-BN layer is essential for the nucleation of c-BN, and the optimum conditi ons needed for the nucleation and growth of the c-BN are different. The nuc leation of c-BN is only possible at a certain substrate negative bias volta ge, while the growth of c-BN films may occur with the wider range of substr ate negative bias voltage. The effects of the substrate negative bias volta ge on the infrared absorption spectra of the films with the h-BN layer were also investigated. (C) 2000 Elsevier Science B.V. All rights reserved.