公开(公告)号：US20230130753A1

公开(公告)日：2023-04-27

申请号：US17970439

申请日：2022-10-20

Applicant: Meta Platforms Technologies, LLC

Inventor： Keren ZHANG ,  Xu ZHANG ,  Feyza DUNDAR ARISOY ,  Joshua Andrew KAITZ ,  Ankit VORA ,  Elliott FRANKE ,  John SPORRE

IPC: G03F7/039 ,  G03F7/09

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.