Multiple substrate microwave plasma-assisted chemical vapor deposition single crystal diamond synthesis

A multiple substrate, microwave plasma-assisted chemical vapor deposition synthesis process for single crystal diamond (SCD) is demonstrated using a 915MHz reactor. Diamond synthesis was performed using input chemistries of 6–8% of CH4∕H2, microwave input powers of 10–11.5kW, substrate temperatures of 1100–1200°C, and pressures of 110–135Torr. The simultaneous synthesis of SCD over 70 diamond seeds yielded good quality SCD with deposition rates of 14–21μm∕h. Multiple deposition runs totaling 145h of deposition time added 1.8–2.5mm of diamond material to each of the 70 seed crystals.