PLASMA-ASSISTED CVD OF DIAMOND FILMS BY HOLLOW-CATHODE ARC-DISCHARGE

The preparation of polycrystalline diamond particles and thin diamond films by deposition in the plasma discharge of a hollow cathode arc has been investigated. Although this discharge is known as a very simple and effective system for plasma generation, there has been little information about the growth of diamond by means of this method up to now. This type of discharge combines thermal and plasma dissociation of the reactant gases for diamond deposition. The temperature of the deposition area can be easily controlled by the electron current to the substrate and thus no auxiliary heating system is required, in contrast to many other diamond deposition methods. Furthermore, we assume additional decomposition of the reactant gases at the surface of the substrate due to the strong electron bombardment. As-deposited diamond particles and films were investigated by various electron microscopy methods, Raman spectroscopy and optical methods. They clearly show a polycrystalline structure with good crystallinity and quality. The diamond growth rate reaches about 2 mum h-1 on a deposition area of about 4 cm2.