Nucleation and growth of diamond films on aluminum nitride by hot filamentchemical vapor deposition

Nucleation and growth of diamond films on aluminum nitride (ALN) coatings w ere investigated by scanning electron microscopy, Raman spectroscopy and sc ratch test. ALN films were grown in a magnetron sputtering deposition. The substrates were Si(111) and tungsten carbide (WC). Chemical vapor depositio n (CVD) diamond films were deposited on ALN films by hot filament CVD. The nucleation density of diamond on ALN films was found to be approximately 10 (5) cm(-2), whereas over 10(10) cm(-2) after negative bias pre-treatment fo r 35 min was -320 V, and 250 mA. The experimental studies have shown that t he cm stresses were greatly minimized between diamond overlay and ALN films as compared with WC substrate. The results obtained have also confirmed th at the ALN, as buffer layers, can notably enhance the adhesion force of dia mond films on the WC. (C) 2000 Elsevier Science S.A. All rights reserved.