There are provided a reflective mask blank, a reflective mask, a reflective mask manufacturing method, and a reflective mask correction technique capable of reducing time required for electron beam correction etching, even when a material used for a thin absorption film has a large extinction coefficient k to an EUV light. A reflective photomask blank (10) according to this embodiment has a substrate (1), a multi-layer reflective film (2), a capping layer (3), and a low reflective portion (5), in which the low reflective portion (5) is obtained by alternately depositing an absorption film (A) and an absorption film (B), the correction etching rate in the electron beam correction of the absorption film (A) is larger than the correction etching rate in the electron beam correction of the absorption film (B), and the absorption film (B) contains one or more elements selected from tin, indium, platinum, nickel, tellurium, silver, and cobalt.

A blankmask for extreme ultraviolet lithography includes a reflection film, a capping film, and an absorbing film that are sequentially formed on a transparent substrate, in which the reflection film has a surface roughness of 0.5 nm Ra or less. It is possible to prevent footing of an EUV photomask pattern from occurring, improving flatness of an EUV blankmask, and prevent oxidation and defects of a capping film.

A blankmask for extreme ultraviolet lithography includes a reflection film, a capping film, and an absorbing film that are sequentially formed on a transparent substrate, in which the reflection film has a surface roughness of 0.5 nm Ra or less. It is possible to prevent footing of an EUV photomask pattern from occurring, improving flatness of an EUV blankmask, and prevent oxidation and defects of a capping film.

The present disclosure describes a method of patterning a semiconductor wafer using extreme ultraviolet lithography (EUVL). The method includes receiving an EUVL mask that includes a substrate having a low temperature expansion material, a reflective multilayer over the substrate, a capping layer over the reflective multilayer, and an absorber layer over the capping layer. The method further includes patterning the absorber layer to form a trench on the EUVL mask, wherein the trench has a first width above a target width. The method further includes treating the EUVL mask with oxygen plasma to reduce the trench to a second width, wherein the second width is below the target width. The method may also include treating the EUVL mask with nitrogen plasma to protect the capping layer, wherein the treating of the EUVL mask with the nitrogen plasma expands the trench to a third width at the target width.

Provided are a substrate with a multilayer reflective film, a reflective mask blank, a reflective mask, and a method for manufacturing a semiconductor device, having high resistance to an etching gas used for etching an absorber film and/or an etching mask film and capable of suppressing occurrence of blister.

A substrate with a multilayer reflective film 100 comprises a substrate 10, a multilayer reflective film 12 formed on the substrate 10, and a protective film 14 formed on the multilayer reflective film 12. The protective film 14 comprises ruthenium (Ru), rhodium (Rh), and at least one additive element selected from the group consisting of titanium (Ti), zirconium (Zr), yttrium (Y), niobium (Nb), vanadium (V), and hafnium (Hf).

Provided are a substrate with a multilayer reflective film, a reflective mask blank, a reflective mask, and a method for manufacturing a semiconductor device, having high resistance to an etching gas used for etching an absorber film and/or an etching mask film and capable of suppressing occurrence of blister.

A substrate with a multilayer reflective film 100 comprises a substrate 10, a multilayer reflective film 12 formed on the substrate 10, and a protective film 14 formed on the multilayer reflective film 12. The protective film 14 comprises ruthenium (Ru), rhodium (Rh), and at least one additive element selected from the group consisting of titanium (Ti), zirconium (Zr), yttrium (Y), niobium (Nb), vanadium (V), and hafnium (Hf).

A reflective mask includes a substrate, a reflective multilayer disposed on the substrate, a capping layer disposed on the reflective multilayer, and an absorber layer disposed on the capping layer. The absorber layer includes a base material made of one or more of a Cr based material, an Ir based material, a Pt based material, or Co based material, and further contains one or more additional elements selected from the group consisting of Si, B, Ge, Al, As, Sb, Te, Se and Bi.

A method for forming a photomask includes receiving a mask substrate including a protecting layer and a shielding layer formed thereon, removing portions of the shielding layer to form a patterned shielding layer, and providing a BSE detector to monitor the removing of the portions of the shielding layer. When a difference in BSE intensities obtained from the BSE detector is greater than approximately 30%, the removing of the portions of the shielding layer is stopped. The BSE intensity in following etching loops becomes stable.

A method for forming a photomask includes receiving a mask substrate including a protecting layer and a shielding layer formed thereon, removing portions of the shielding layer to form a patterned shielding layer, and providing a BSE detector to monitor the removing of the portions of the shielding layer. When a difference in BSE intensities obtained from the BSE detector is greater than approximately 30%, the removing of the portions of the shielding layer is stopped. The BSE intensity in following etching loops becomes stable.

A reflective mask includes a substrate, a reflective multilayer disposed on the substrate, a capping layer disposed on the reflective multilayer, a photo catalytic layer disposed on the capping layer, and an absorber layer disposed on the photo catalytic layer and carrying circuit patterns having openings. Part of the photo catalytic layer is exposed at the openings of the absorber layer, and the photo catalytic layer includes one selected from the group consisting of titanium oxide (TiO.sub.2), tin oxide (SnO), zinc oxide (ZnO) and cadmium sulfide (CdS).