Deposition of BCN layers from B-C-N-H single source precursors

This work deals with the deposition of BxCyNy phases by decomposition of a B, C, N containing single source precursor called Tris(dimethylamino)borane in a hot-filament CVD apparatus. In contrast to the deposition of diamond layers the deposition of cubic-BN or cubic-BxCyNz phases with low pressure CVD-methods was not successfully until now. To avoid the problems of filament failure and deposition of Ta into the produced layers, the Ta-filaments were pre-treated by carburization or nitridation. BCN layers were deposited an Si and on WC-Co substrates in a hydrogen atmosphere similar to diamond deposition. Layers deposited an Si showed higher growth-rates than layers deposited an WC-Co at the same deposition conditions. An increase of the filament temperature led to an increasing growth rate. This increase of growth rate was caused by higher BCN decomposition but also by additional Ta incorporation. At filament temperatures higher than 2200 oC Ta evaporated much easier from the filament. An increase of the precursor flow rate as well led to an increase in the deposition rate an both types of the investigated substrates. Layers produced at a precursor flow rate of 1,7x10-5 mol/min showed some weak peaks in Raman and IR spectra, but none of the phases that exist in the ternary BCN system could be clearly identified. The morphology of the layers was investigated by SEM. (author)