US 11,835,851 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. 17/463,675.
Claims priority of application No. 2020-151705 (JP), filed on Sep. 10, 2020.
Prior Publication US 2022/0075254 A1, Mar. 10, 2022
Int. Cl. G03F 1/24 (2012.01); G03F 7/00 (2006.01)
CPC G03F 1/24 (2013.01) [G03F 7/70033 (2013.01)] 16 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,
a layer containing Si and N intervenes at one or more portions between the Si layer and the Mo layer of the Si/Mo laminated portion, and is contact with both of the Si layer and the Mo layer,
the multilayer reflection film further comprises a protection layer containing Ru formed in contact with the Si/Mo laminated portion, as the uppermost layer,
the protection layer is contact with the Mo layer of the Si/Mo laminated portion,
the uppermost part of the multilayer reflection film consists of, from the side remote from the substrate, the protection layer, the Mo layer, the layer containing Si and N, and the Si layer, and
the Mo layer in the uppermost part has a thickness of not more than 1 nm.