Chemical vapor deposition of an aluminum nitride-diamond composite in a triple torch plasma reactor

An aluminum nitride-diamond composite has been produced by sequential depos ition of AlN and diamond in a triple torch plasma reactor (TTPR). AlN was d eposited from AlN powder by injection into the argon-nitrogen, converging p lasma plume of a TTPR. Velocity and temperature profiles of the converging plasma plume, obtained by enthalpy probe measurements, were used to show th at the powder decomposed prior to reaching the substrate. Diamond was depos ited in an argon-hydrogen-methane system onto the existing AlN film. Charac terization of an AlN-diamond-AlN composite indicated a Vickers hardness of 18.6 GPa and a modulus of elasticity of 245-282 GPa.