Ion bombardment as the initial stage of diamond film growth

It is believed that during the initial stage of diamond film growth by chem ical-vapor deposition (CVD), ion bombardment is the main mechanism in the b ias-enhanced-nucleation (BEN) process. To verify such a statement, experime nts by using mass-separated ion-beam deposition were carried out, in which a pure carbon ion beam, with precisely defined low energy, was selected for investigating the ion-bombardment effect on a Si substrate. The results ar e similar to those of the BEN process, which supports the ion-bombardment-e nhanced-nucleation mechanism. The formation of sp(3) bonding is based on th e presumption that the time of stress generation is much shorter than the d uration of the relaxation process. The ion-bombarded Si is expected to enha nce the CVD diamond nucleation density because the film contains amorphous carbon embedded with nanocrystalline diamond and defective graphite. (C) 20 01 American Institute of Physics.