Tribochemical action on the tribochemical mechanical lapping (0001) C plane of the SiC single-crystal substrate

The SiC single-crystal substrate with ultrasmooth and damage-free properties has potential applications in the field of optoelectronics and microelectronics. Lapping is one of the important processes for ultraprecision machining of the SiC single-crystal substrate. The lapping quality has an important impact on the surface quality, processing time, processing cost and processing efficiency of the subsequent chemical mechanical polishing (CMP) of the SiC single-crystal substrate. In this paper, four kinds of lapping pastes with different ingredients were prepared. The tribochemical action and mechanism of the oxidant in the lapping paste were studied. The results show that NaOH can be used as an oxidant for the tribochemical mechanical lapping of the SiC single crystal. Under the catalysis of iron oxide and frictional force, the tribochemical reaction between the SiC single-crystal substrate and the oxidant NaOH occurred and the silicon oxides (such as SiO2), gaseous carbon oxides and other reactants were produced. The surface energy of the SiC substrate was reduced and the material removal rate was improved effectively. These results can provide a reference for further research on the mechanism of tribochemical mechanical lapping.