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 915 MHz reactor. Diamond synthesis was performed using input chemistries of 6-8% of CH4/H-2, microwave input powers of 10-11.5 kW, substrate temperatures of 1100-1200 degrees C, and pressures of 110-135 Torr. The simultaneous synthesis of SCD over 70 diamond seeds yielded good quality SCD with deposition rates of 14-21 mu m/h. Multiple deposition runs totaling 145 h of deposition time added 1.8-2.5 mm of diamond material to each of the 70 seed crystals.