EVIDENCE OF THE ROLE OF POSITIVE BIAS IN DIAMOND GROWTH BY HOT-FILAMENT CHEMICAL-VAPOR-DEPOSITION

Diamond films have been deposited on a positively biased silicon subst rate by hot filament chemical vapor deposition. It is found that the s ize distribution of the diamond particle is uniform under bias conditi ons. The effects of the bias on reactive gas composition were investig ated by in situ infrared absorption and in situ optical emission with Ar actinometry. These techniques indicate that the bias does not signi ficantly influence the gas composition. Diamond growth under bias cond itions for a small region masked by metal Mo is similar to that withou t bias. These results confirm that the influence of bias on diamond gr owth is caused by electron and/or negative ion bombardment on the surf ace of the substrate and the growing crystallites rather than by the c hange in gaseous environments. (C) 1996 American Institute of Physics.