ION-BEAM-ASSISTED PLANARIZATION OF CHEMICALLY VAPOR-DEPOSITED DIAMONDTHIN-FILMS USING ELECTRON-CYCLOTRON-RESONANCE PLASMA

The high inherent surface roughness of as-deposited polycrystalline di amond films has made effective planarization processing of these films essential for most industrial applications. We have investigated the efficacy of ion beam sources for planarization in an electron cyclotro n resonance plasma system using both direct substrate biasing and an a ccelerating grid system. Rough polycrystalline diamond films were synt hesized using hot filament chemical vapor deposition. Both the etching rates and the resultant surface roughnesses were found to decrease as the angle of incidence (relative to the substrate surface normal) of the ion beam was increased. In the case of direct biasing of the sampl e, acicular features were observed following processing at higher inci dent angles. The use of double ion-extraction grids in conjunction wit h concomitant sample rotation was found to produce more uniform planar ization of the diamond films. The rate of surface roughness reduction was found to be nonlinear and decreased with time. For both ion extrac tion methods investigated, the average film roughness (R-a) was signif icantly reduced from 0.2 to 0.05-0.06 mu m.