High-efficiency super-smooth chemical mechanical polishing method for lithium niobate crystal

Abstract

The invention discloses a high-efficiency super-smooth chemical mechanical polishing method for a lithium niobate crystal and belongs to the technical field of ultraprecision machining of nonlinear optical crystals. The high-efficiency super-smooth chemical mechanical polishing method is characterized in that a sample is a lithium niobate crystal; the lithium niobate crystal is processed by adopting a method of combining grinding of bonded abrasives, polishing of a retaining ring hard polishing pad and chemical mechanical polishing of a retaining ring soft polishing pad, wherein the hard polishing pad is a synthetic leather or polyurethane polishing pad; the soft polishing pad is non-woven fabric or fuzzy polishing pad; a pH value of a chemical mechanical polishing solution is 10.2-10.6; the chemical mechanical polishing solution contains four kinds of cerium oxide, silicon oxide, potassium hydroxide, sodium hydroxide, barium hydroxide, potassium permanganate, hydrogen peroxide, citric acid, acetic acid and oxalic acid; the grinding time of the bonded abrasives is 15-25 minutes; the polishing time of the hard polishing pad is 50-70 minutes; the chemical mechanical polishing time is 3-6 minutes; the removal rate of materials for chemical mechanical polishing is 420-460nm/min; the planeness of the polished lithium niobate is 3.8-5.5[mu]m; the surface roughness Ra of the polished lithium niobate is 0.35-0.5nm and the PV value of the polished lithium niobate is 3.8-6nm. The high-efficiency super-smooth chemical mechanical polishing method disclosed by the invention has the beneficial effect that a high-efficiency super-smooth polishing method of a nonlinear optical crystal is realized.

Description

technical field [0001] A lithium niobate crystal high-efficiency ultra-smooth chemical-mechanical polishing method belongs to the technical field of nonlinear optical crystal ultra-precision processing, and in particular relates to a processing method for nonlinear optical crystal chemical-mechanical polishing. Background technique [0002] Due to its excellent ferroelectric, piezoelectric, electro-optical, nonlinear optics, surface acoustic wave and other properties, lithium niobate crystals are widely used in optoelectronic fields such as optical waveguide substrates, optical communication modulators, and optical isolators. Memory, optical integration and other fields have broad application prospects, occupy a monopoly position in the field of nonlinear optics, and enjoy the reputation of optical silicon. Lithium niobate crystals not only have excellent photoelectric properties, but also have unique mechanical properties. Bulletin of Materials Science, 2000, 23(2), 147-15...

AI Technical Summary

Problems solved by technology

The traditional chemical mechanical polishing method has low processing efficiency, poor processing accuracy and high processing cost, and it