Evidence of the role of positive bias in diamond growth by hot filament chemical vapor deposition

Abstract

Diamond films have been deposited on a positively biased silicon substrate by hot filament chemical vapor deposition. It is found that the size distribution of the diamond particle is uniform under bias conditions. The effects of the bias on reactive gas composition were investigated by in situ infrared absorption and in situ optical emission with Ar actinometry. These techniques indicate that the bias does not significantly influence the gas composition. Diamond growth under bias conditions for a small region masked by metal Mo is similar to that without bias. These results confirm that the influence of bias on diamond growth is caused by electron and/or negative ion bombardment on the surface of the substrate and the growing crystallites rather than by the change in gaseous environments.