Effect of alkaline slurries on nano machining CaF2 crystal.

The slurry chemical action affects chemical reaction between the wafer and slurry, and self-conditioning performance of the pad in nano machining process. Fixed abrasive polishing, one of important nano machining technologies, was adopted to achieve a nano precision surface quality of CaF2 crystal. Five kinds of alkaline regulators, triethanolamine, sodium citrate, sodium carbonate, ethylenediamine and sodium phosphate in slurries with pH 10, were screened in nano machining CaF2 crystal. The effect on material removal rate (MRR), surface topography and surface roughness was investigated in fixed abrasive polishing of CaF2 crystal. The results indicated that surface quality is getting better with MRR decreasing. The optimal surface quality of CaF2 crystal with surface roughness Sa 4.13 nm can be obtained by sodium phosphate slurry with MRR224 nm/min in fixed abrasive polishing of CaF2 crystal. The nanometer precision surface quality with high material removal was achieved in nano machining CaF2 crystal. [ABSTRACT FROM AUTHOR]