The effect of ion bombardment on the nucleation of CVD diamond

The nucleation effect of CVD diamond by ion bombardment was studied by a two-step process. In the first step, hydrocarbon and hydrogen ion bombardment was used to induce nucleation on mirror-polished (001) Si substrates. In the second step, diamond films were subsequently deposited on the ion-bombarded substrates by a conventional hot filament chemical vapor deposition. It was found that after the ion bombardment, an amorphous layer embedded with nano-crystalline diamond particles formed on the Si substrate. These nano-crystalline diamond particles were proposed to serve as the nucleation centers for the growth in the second step. The nucleation density depended strongly on the ion dosage and a nucleation density of up to 2 x 10(9) cm(-2) could be achieved under optimized conditions. (C) 1999 Elsevier Science S.A. All rights reserved.