SUPERPOLISHING METHOD AND SLURRY FOR IT

摘要

PURPOSE: To obtain a superpolishing method which polishes the surface of a disk substrate to the smoothness of an atom level. CONSTITUTION: This superpolishing method uses a chemical finishing treatment and a mechanical finishing treatment in combination. The surface of the disk substrate subjected to machining to prescribed surface roughness (namely, rough machining) is susceptible to erosion of an etching material. The substrate material is softened by the etching material in this slurry. The softened substrate material is thereafter wiped away and removed by the mechanical effect of the soft colloidal particles included in the slurry. As a result, the average surface roughness lower by one order than the disk surface subjected to the polishing treatment by the hard particles is attainable with the resulted disk substrate surface.