ABSTRACT
For the diffusion etching process to continue, the carbon flux must not be blocked at the interface between diamond and the metal. Diamond films may also be etched with hot steel or other carbon metal solvent under hydrogen atmosphere to allow continual removal. In addition to be able to continue the polishing process of diamond film, the temperature required in etching under hydrogen atmosphere is lower than that for pure mechanical polishing or diffusion etching. Because of the slower removal rate at lower temperature, diamond film polished under hydrogen atmosphere is smoother than that in vacuum. Moreover, the stress applied to the diamond film may also be greatly reduced. Alternatively, clusters of argon ion may also be used to flatten the diamond film. The diffusion etching of diamond film will leave a back carbon coating on the protruded areas. They can be mechanically polished at room temperature using abrasives.
