Abstract

Numerically controlled local wet etching (NC-LWE) is a novel figuring method for fabricating ultraprecision optics or finishing the functional materials. In this method, localized etching area is formed by nozzle that is constructed from the supply part and the suction part of etchant, and the removal volume at anywhere on the workpiece surface is determined by the dwelling time of the nozzle. We applied the NC-LWE for finishing the photomask substrate made of quartz glass, and achieved 69 nm peak to valley flatness with 0.15 nm rms roughness.

© 2006 Optical Society of America