Planarization of Lithium Niobate Surface Using a Thin Film Catalyst in Pure Water

A catalytically assisted etching method, named Catalyst-Referred Etching (CARE) was applied to the planarization of Lithium Niobate (LN) surface, which is widely used for optical waveguides, modulators, piezoelectric applications. The study demonstrates that an atomically smooth surface with less than 0.1 nm root-mean-square roughness could be achieved on a LN substrate using thin metal film and pure water as catalyst solution, respectively. All residual stress damage removed completely thanks removal mechanism CARE.