Patent ID: 11860529
Assignee: SHIN-ETSU CHEMICAL CO., LTD.
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 0:
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.