Reflective mask blank and method for manufacturing reflective mask blank
AssigneeShin-Etsu Chemical Co., Ltd.
InventorsTakuro KOSAKA, Yukio INAZUKI, Taiga OGOSE
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Abstract
A reflective mask blank used in EUV lithography using EUV light as exposure light comprising at least a substrate 10; a multilayer reflective film 50 that is formed on the substrate 10 and reflects exposure light; and a multilayer film 200 containing tantalum (Ta). The multilayer film 200 has a TaN part 210, a TaO part 230, and a Ta part 220 provided between the TaN part 210 and the TaO part 230. A density of the Ta part 220 is higher than densities of the TaN part 210 and the TaO part 230. The density of the Ta part 220 is 13 g/cm3 or more.
Claims11
A reflective mask blank used in EUV lithography using EUV light as exposure light comprising at least a substrate;
- a multilayer reflective film that is formed on the substrate and reflects exposure light;
- and a multilayer film containing tantalum (Ta),
- wherein the multilayer film has a TaN part, a TaO part, and a Ta part provided between the TaN part and the TaO part,
- wherein a density of the Ta part is higher than densities of the TaN part and the TaO part, and
- wherein the density of the Ta part is 13 g/cm3 or more.
Dependencies are inferred from the claim text.