ENHANCEMENT OF DIAMOND NUCLEATION BY ULTRASONIC SUBSTRATE ABRASION WITH A MIXTURE OF METAL AND DIAMOND PARTICLES

A method of surface treatment was found to enhance diamond chemical vapor deposition nucleation on nondiamond substrates such as Si, SiO2, and Al2O3. The nucleation density obtained by ultrasonic abrasion with diamond powder alone was found to be enhanced by a few orders of magnitude using a mixed slurry consisting of diamond and metal powders. No strong nucleation enhancement was observed using a metal slurry only for surface treatment. The metal powders used were W, Ta, Mo, Nb, Ti, Al, Fe, Ni, Cu, and Si. It is concluded that the enhanced nucleation is associated with a physico-chemical modification of the substrate surface, attained through a cooperative effect of both the metal and diamond particles during the ultrasonic abrasion process.© 1995 American Institute of Physics.