Fast fabrication of nanocrystalline and 100 faceted polycrystalline diamond films by using stepped method

Nanocrystalline and ＜100＞ oriented 100 faceted polycrystalline diamond films can be deposited simultaneously in one deposition run by high power microwave plasma chemical vapor deposition (MPCVD) and using stepped method for substrate arrangement. Focus was made on comparing the difference on diamond products and their growth rate in one deposition run and among different growth processes. When microwave power was increased from 2.0 kW to 3.2 kW, the growth rate of nanocrystalline diamond (NCD) film grown on the bottom big Si wafer was enhanced from 0.3 μm/h up to 3.0 μm/h; while the growth rate for diamond products grown on the top small Si slices was 3.8 μm/h for NCD film at 2.0 kW and raised to 11.2 μm/h for ＜100＞ oriented 100 faceted large-grained polycrystalline diamond film at 3.2 kW. Furthermore, the diamond products near the edge and corner of the small Si slice are different from that grown on the center of the same substrate, namely the edge effect is pronounced, and the growth rate was further improved, ranging from 17.0 μm/h up to 27.1 μm/h. This work clearly demonstrates the versatility of N₂ and O₂ addition on diamond growth by using stepped method and further deepen the understanding of the complicated diamond growth process by high power MPCVD.