Reflective mask blank and manufacturing method of reflective mask
AssigneeShin-Etsu Chemical Co., Ltd.
InventorsYukio INAZUKI, Takuro KOSAKA, Taiga OGOSE, Keisuke SAKURAI, Shohei MIMURA, Hideo KANEKO
Life of this patent
Estimating the term…
Abstract
As a reflective mask blank that includes a protection film containing ruthenium (Ru), a reflective mask blank in which the protection film is hard to be damaged and can be suppressed decrease of the thickness is provided by a reflective mask blank including a substrate, a multilayer reflection film, a protection film, an absorption film, and an etching prevention film that contains niobium (Nb) and is free of ruthenium (Ru) between the protection film and the absorption film.
Claims9
A reflective mask blank which is a material for a reflective mask used in EUV lithography utilizing EUV light as exposure light, comprising
- a substrate,
- a multilayer reflection film that is formed on one main surface of the substrate, and reflects the exposure light,
- a protection film for protecting the multilayer reflection film that is formed on the multilayer reflection film, and
- an absorption film that is formed on the protection film, and absorbs the exposure light, wherein
- the protection film comprises ruthenium (Ru), and
- the reflective mask blank further comprises an etching prevention film that comprises niobium (Nb) and is free of ruthenium (Ru) between the protection film and the absorption film.
Dependencies are inferred from the claim text.