NUCLEATION OF CUBIC BORON-NITRIDE (C-BN) WITH ION-INDUCED PLASMA-ENHANCED CVD

Nucleation and growth of c-BN films by means of the inductively couple d plasma technique was investigated. Two different sets of experiments were performed: deposition as a function of the bias voltage V-B and experiments with varying deposition times. The films were characterize d by Fourier transform IR spectroscopy, Auger electron spectroscopy an d ellipsometry. Without substrate bias, crystalline h-BN was obtained, oriented with the c-axis normal to the surface. With sufficient bias voltage, a layer of vertically oriented h-BN was observed prior to the formation of c-BN, in agreement with transmission electron microscopy measurements published recently in the literature. We observed furthe r a significant increase in the boron to nitrogen ratio prior to the f ormation of c-BN. Preferential sputtering of nitrogen with respect to boron with increasing ion bombardment seems to be the reason for this behaviour.