US 11,860,529 B2
Substrate with multilayer reflection film for EUV mask blank, manufacturing method thereof, and EUV mask blank
Yukio Inazuki, Joetsu (JP); Tsuneo Terasawa, Joetsu (JP); Takuro Kosaka, Joetsu (JP); Hideo Kaneko, Joetsu (JP); and Kazuhiro Nishikawa, Joetsu (JP)
Assigned to SHIN-ETSU CHEMICAL CO., LTD., Tokyo (JP)
Filed by Shin-Etsu Chemical Co., Ltd., Tokyo (JP)
Filed on Sep. 1, 2021, as Appl. No. 17/463,862.
Claims priority of application No. 2020-151709 (JP), filed on Sep. 10, 2020.
Prior Publication US 2022/0075255 A1, Mar. 10, 2022
Int. Cl. G03F 1/24 (2012.01)
CPC G03F 1/24 (2013.01) 22 Claims
 
1. A substrate with a multilayer reflection film for an EUV mask blank comprising a substrate, and a multilayer reflection film formed on the substrate, wherein
the multilayer reflection film comprises a Si/Mo laminated portion in which Si layers and Mo layers are alternately laminated, and a protection layer containing Ru formed on the Si/Mo laminated portion and in contact with the Si/Mo laminated portion, as the uppermost layer,
the protection layer comprises a lower layer formed in contact with the Si/Mo laminated portion, and an upper layer formed at the side remotest from the substrate,
the lower layer is composed of Ru,
the upper layer is composed of a material containing Ru and at least one selected from the group consisting of metals other than Ru, and metalloids,
the protection layer is contact with the Mo layer of the Si/Mo laminated portion, and
the uppermost part of the multilayer reflection film consists of, from the side remote from the substrate, the protection layer, the Mo layer, a layer containing Si and N, and the Si layer.