Superpolishing sapphire: A method to produce atomically flat and damage free surfaces

Abstract Superpolishing of sapphire is done in direct contact to a rotating tin lap using silica aquasol as a polishing liquid. The roughness is studied with a Talystep profiler, and the crystallinity of the upper atomic layers is investigated by RHEED technique. The extremely small stock-removal rates are determined as a function of each important working parameter with all other parameters unchanged. These results are discussed in terms of the hydrothermal wear model.