The myth exists that plasma processing is synonymous with dirty processing. while plasma processing can be a dirty Process, it can also be an exceptionally clean process. Diamond etching by a Plasma process is, in tact, a cleaner process than experienced in any other semiconductor by any other means --- the residue (carbon monoxide) is gaseous and the etch recess/trough is exceptionally clean and undamaged. Artifact diamond films are grown by highly non-thermal equilibrium processes. Most of these processes are plasma processes. Virtually all types of plasmas have been used to synthesize diamond. Among the most-used types are R.F., D.C., and remote plasmas. Plasmas are also used to provide in situ cleaning of the substrate surface prior to growth. Although the diamond surface is one of exceptionally high surface energy (virtually nothing sticks to it) and requires comparatively little cleaning, the economical growth of diamond requires non-diamond substrates which do require cleaning. Artifact diamond grown by various plasma processes are compared with each other and with other growth methods.
Max N . Yoder, Max N . Yoder,
"Plasma-Enhanced Processing Of Diamond Films", Proc. SPIE 1037, Monitoring and Control of Plasma-Enhanced Processing of Semiconductors, (15 March 1989); doi: 10.1117/12.951021; https://doi.org/10.1117/12.951021