Deposition of diamond coatings on particles in a microwave plasma-enhanced fluidized bed reactor

Diamond growth on non-diamond particles in a fluidized bed reactor by microwave plasma-enhanced chemical vapor deposition (MPECVD) is reported. Si and SiO2 powders are used as seed particles without pretreatment, and a 0.5–2.0% CH4 in H2 mixture with addition of 0–3% O2 is used as the fluidizing gas as well as the carbon source. SEM images show that good quality diamond is deposited on Si and SiO2 particles after 8 h at 9 Torr with flow rates of 160 seem of 2.0% CH4 in H2 and 3 sccm of O2.