Abstract: The disclosed method for recovering optical properties of transparent substrates may include performing a post-etching annealing process on a transparent substrate. The method may also include applying a plasma treatment to the transparent substrate, performing an atomic layer etching treatment on the transparent substrate, and/or performing a cleaning process. Various other methods, devices, and systems are also disclosed.

Abstract: Disclosed herein are techniques for fabricating a straight or slanted surface-relief grating with a uniform or non-uniform grating depth. According to certain embodiments, a gray-tone photoresist includes a novolac resin, a diazonaphthoquinone (DNQ) dissolution inhibitor, and one or more crosslinking agents for crosslinking the novolac resin at an elevated temperature to increase a glass transition temperature of the gray-tone photoresist and/or lower an etch rate of the gray-tone photoresist. After gray-tone photo exposure and development, the gray-tone photoresist is baked at the elevated temperature to crosslink. The crosslinked gray-tone photoresist has a higher density and a higher glass transition temperature, and thus would not become flowable to cause ripples or other surface roughness during the etching.