Characterization of cubic boron nitride films grown by mass separated ion beam deposition

Abstract

We have prepared BN films by ion beam deposition of mass separated low energy 11B + and 14N + ions with energies between 100 and 500 eV. The silicon substrates were kept at room temperature or heated up to 350°C. The films were characterized with Auger electron spectroscopy and Rutherford backscattering. The influence of ion energy, ion flux and substrate temperature on the c-BN formation will be discussed. Successful synthesis of cubic boron nitride (c-BN) with a phase purity up to 80% is confirmed by infrared absorption spectroscopy, transmission electron microscopy (TEM) and transmission electron diffraction (TED). For a film with high c-BN content TEM revealed a growth sequence of an amorphous interface layer, followed by few nm of highly oriented hexagonal BN (h-BN) and a layer of nanocrystalline c-BN. We were also able to produce a textured h-BN layer in between two c-BN layers.