公开(公告)号：US20220299862A1

公开(公告)日：2022-09-22

申请号：US17835742

申请日：2022-06-08

Applicant: AGC Inc.

Inventor： Daijiro AKAGI ,  Hirotomo KAWAHARA ,  Hiroyoshi TANABE ,  Toshiyuki UNO

IPC: G03F1/24 ,  G03F1/26 ,  G03F1/52 ,  G03F1/80

Abstract: A reflective mask blank for EUV lithography includes, in the following order, a substrate, a multilayer reflective film for reflecting EUV light, a phase shift film for shifting a phase of EUV light, and an etching mask film. The phase shift film is constituted of a ruthenium-based material containing ruthenium as a main component. The phase shift film has a film thickness of 20 nm or larger. The etching mask film is removable with a cleaning liquid comprising an acid or a base.