Effects of pre-treatments of substrates on synthesis of diamond thin films

In the present study, we investigated deposition of diamond films on both Si substrates pre-treated with diamond powder by an ultrasonic vibrator and also further ion-implanted. The pre-treatment with diamond powders increased a density of diamond nucleation on Si substrate by five-order of magnitude against to the untreated substrate. 280keV Ar+ ion implantation at 90K to the pre-treated substrate significantly reduced the density of the diamond nucleation while the implantation at 773K scarcely affected the density. It is proposed that healing of micro-flaws, which are thought to work as the nucleation sites, is an important mechanism to reduce the diamond nucleation density by ion implantation.