LASER PHYSICOCHEMICAL VAPOR-DEPOSITION OF CUBIC BORON-NITRIDE THIN-FILMS

A laser physico-chemical vapour deposition (LPCVD) technique was devel oped based on the interaction of an ultraviolet laser beam with a boro n nitride target and borazine gas to synthesize cubic boron nitride (C BN) thin films on silicon substrates. The process involved a hybrid of pulsed laser ablation (PLA) of a solid HBN target and chemical vapour deposition (CVD) using borazine as a feed stock. The films were chara cterized with scanning electron microscopy, X-ray diffraction and infr ared spectroscopy. Results indicate that the thin films consisted of a lmost single-crystalline CBN structures and that the film quality in t erms of adherence, particulate density and smoothness was excellent. T he purity and crystal structure of target material, laser beam wavelen gth and energy fluence were the key variables that controlled the film characteristics. In contrast to LPCVD, the conventional PLA method di d not generate CBN films.