DIRECT-CURRENT BIAS EFFECT ON THE SYNTHESIS OF (001)-TEXTURED DIAMOND FILMS ON SILICON

A diamond film consisting of almost 100% [001] grains can be synthesized at a fast rate (similar to 3 mu m/h) by a two-step process. First, the nuclei are formed under -160 V dc bias with 3 mol % CH4/H-2 at 900 degrees C substrate temperature and then the films are grown under -100 V dc bias with around 5-6 mol % CH4/H-2 at the same temperature. The nucleation of the diamond is enhanced by using bias voltage. The a and b axis of [001] textured diamond films grown under large bias voltage are aligned with a and b axes of silicon, viz. (100)(diamond)\\(100)(Si) and [110](diamond)\\[110](Si). The effect of bias voltage on the growth behavior of the diamond films is accounted for by the suppression of the growth of the non-[001] grains due to the electron emission under bias. (C) 1995 American Institute of Physics.