Abstract

Multilayer coated optics in a soft x-ray projection lithography system are subject to environmental effects that can degrade their performance such as corrosion, contamination and excessive radiation exposure. When the damage is limited to the multilayer coatings it is cost effective to recycle the optics by removing the damaged coatings and recoating the substrates. The main challenge is to develop a substrate recovery process that completely removes the coating without compromising the figure and surface finish requirements of the original substrate. Typical requirements for the precision imaging optics are a surface finish of less than 1 Å root-mean-square (RMS) and peak-to-valley figure error of less than 10 Å.

© 1993 Optical Society of America