ABSTRACT
This chapter considers diamond chemical vapour deposition (CVD) using radio-frequency (RF) plasmas. RF plasmas are generated by power sources with frequencies of hundreds of kHz to tens of MHz. Thermal RF plasmas are almost always induction plasmas, while glow discharge plasmas of both capacitive and inductive types have been used for diamond CVD. Thermal plasmas, in contrast, are characterized by heavy species temperatures which are roughly equilibrated with the electron temperature. Induction plasmas in the thermal plasma regime have much in common with direct current (DC) thermal plasmas, and to a lesser extent with combustion flames. As with DC thermal plasmas and combustion flames, RF thermal plasmas expose the deposition substrate to a high heat load, and the substrate must be actively cooled to maintain a low enough temperature for diamond deposition. The widespread use of RF parallel-plate capacitive plasmas makes them ideal candidates for diamond CVD.
