DEPOSITION OF DIAMOND AND BORON-NITRIDE FILMS BY PLASMA CHEMICAL-VAPOR-DEPOSITION

The deposition problems of diamond and cubic boron nitride (c-BN) by c hemical vapour deposition techniques are reviewed, with major emphasis on the nucleation and reaction mechanisms. A discussion is made of th e main deposition parameters (i.e. gas mixture, substrate conditioning , plasma discharges etc.) which favour the formation of the cubic phas e. Most of the work is devoted to diamond owing to the large progress attained in this material. In fact, the use of diamond as a hard prote ctive coating is now on a commercial scale. By contrast, the preparati on of c-BN layers with good characteristics still needs of further res earch.