DC 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 VDC bias with 3 mol% CH4/H-2 at 900 degrees C substrate temperature and then the films are grown under -100 VDC bias with around 5 similar to 6 mol% CH4/H-2 at the same temperature. The nucleation of the diamond is enhanced by using bias voltage. The a- and b-axes of [001] textured diamond films grown under large bias voltage are aligned with a- and bof axes of silicon, viz. (100)(dia) parallel to (100)(Si) and [100](dia) parallel to [11O](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.