On the influence of substrate temperature for cubic boron nitride growth

BN-films were deposited on Si(100) substrates with r.f. magnetron sputtering of hBN targets. The chemical and the phase composition were determined with Auger electron spectroscopy sputter depth profiling and with Fourier transform infrared spectroscopy; the film stress was measured with the beam-bending method. Temperature dependent deposition studies for a constant substrate bias of −200 V revealed that cBN was formed at substrate temperatures close to room temperature for appropriate values of the N 2-content in the N 2/Ar working gas. The stress is slightly reduced with increasing substrate temperature, and thicker hBN-sublayers seem to improve the film adherence to the substrate. The commonly observed temperature threshold for cBN growth is very probably required to establish full BN stoichiometry as a condition for cBN formation.