Optical monitoring of nucleation and growth of diamond films

摘要

Early stages of diamond film deposition on molybdenum substrates using dcthinsp;arc discharge in CH4/H2gas mixtures were studied byinsitumeasurements of optical reflectivity of growing film. Ultrafine diamond grit of ape;200 Aring; size was used for seeding to increase nucleation density up to 2times;109cmminus;2and to produce smooth thin films. Evolution of Hehyphen;Ne laser beam reflection at 0.63 mgr;m wavelength is described in terms of Mie scattering by nonabsorbing dielectric spheres in the case of nucleated film and of light interference in the system of continuous diamond film on a metal substrate. During the deposition process the growth rate passes through a minimum at the moment when a minimum roughness is supposed to be achieved.