Diamond Film Formation by OH Radical Injection from Remote Microwave H2/H2O Plasma into Parallel-Plate RF Methanol Plasma

Diamond film was successfully synthesized for the first time using a parallel-plate radio-frequency (RF 13.56 MHz) methanol ( CH3OH) plasma assisted by injection of hydrogen (H) and hydroxyl (OH) radicals generated by microwave H2/ H2O plasma. OH radical, in addition to H radical, injection into RF CH3OH plasma enhanced selective diamond growth and selective etching of the nondiamond phase. The effects of OH radical injection on the initial and growth stages of the diamond formation were investigated by changing H2O partial pressure in the microwave plasma. It was found that OH radical injection into RF CH3OH plasma enhanced the growth of diamond in the initial stage.