Structural analysis of cubic boron nitride (111) films heteroepitaxially grown on diamond (111) substrates

Abstract

We investigate the structural properties of cubic boron nitride (c-BN) (111) films heteroepitaxially grown on diamond (111) substrates by ion-beam-assisted molecular beam epitaxy (MBE). Microstructures of the c-BN films depend on the growth temperature (Tg). At Tg above 750 °C, the single-domain epitaxial c-BN (111) films are formed. Higher Tg is effective for improving the surface flatness and suppressing stacking-fault formation on the (11-1) plane. The single-domain c-BN (111) films have nitrogen polarity, implying that C-B bonds are preferentially formed at the c-BN/diamond heterointerface. On the other hand, at low Tg, the c-BN films have a multi-domain structure with epitaxial and rotated domains. We propose a model for the single-domain formation of the heteroepitaxial c-BN (111) films.