Pattern formation method using light-induced suppression of etching

摘要

A method of selectively etching a substrate ( 1 ) comprises applying etchant ( 4 ) at a surface of the substrate and illuminating an area of the surface with light from a light source ( 7 ), whereby etching is at least partially inhibited in the illuminated area ( 18 ) of the substrate. Preferably LiNbO3 is patterned in HF KOH, or HF-HNO3 solutions by selective illumination using UV laser light with 300 to 1000 mn wavelength, thereby allowing for interferometric or holographic structures to be formed.