Insights into the atomic-scale removal mechanism of single crystal diamond in plasma-assisted polishing with quartz glass

The atomic removal mechanism in plasma-assisted polishing (PAP) of single crystal diamond (SCD) substrate is investigated using ReaxFF molecular dynamics simulation. For comparison, another two simulations, polishing without O radical irradiation, polishing with the O atoms' oxidation action omitted, are conducted. C atoms in PAP are removed by attachment to quartz glass via C-O-Si bonds or transformation into non-diamond. Such removals are achieved by the synergistic action of O atoms' oxidation and Si-O-C bonds' dragging force provided by plasma and quartz glass. As a result, material removal rate in PAP is much higher than that in another two cases. Thus, promoting the oxidizing properties of polishing plates and atmospheres is proposed as a route to accelerate diamond polishing efficiency.