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 (/spl sim/3 /spl mu/m/h) by a two-step process. First, the nuclei are formed under -160 VDC bias with 3 mol% CH/sub 4//H/sub 2/ at 900/spl deg/C substrate temperature and then the films are grown under -100 VDC bias with around 5-6 mol% CH/sub 4//H/sub 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 b-axes of silicon, viz. (100)/sub dia//spl par/(100)/sub Si/ and [110]/sub dia//spl par/[110]/sub 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.