Effect of alkaline slurries on nano machining CaF₂crystal

Abstract

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 CaF 2 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 CaF 2 crystal. The effect on material removal rate (MRR), surface topography and surface roughness was investigated in fixed abrasive polishing of CaF 2 crystal. The results indicated that surface quality is getting better with MRR decreasing. The optimal surface quality of CaF 2 crystal with surface roughness Sa 4.13 nm can be obtained by sodium phosphate slurry with MRR 224 nm/min in fixed abrasive polishing of CaF 2 crystal. The nanometer precision surface quality with high material removal was achieved in nano machining CaF 2 crystal.

Nanomanufacturing—Perspective and applications

“…For example, a calcium fluoride (CaF 2 ) crystal is machined by fixed abrasive polishing. The results show that the optimal surface roughness Sa is 4.13 nm when polishing with Na 3 PO 4 slurry while the worst is 8.31 nm when polishing with triethanolamine (TEA) slurry [134]. The slurry is commonly used in free abrasives, with diameters less than 1 mm, dispersed in waterbased solutions; a typical example is polishing slurry.…”