A phase shift mask blank includes a transparent substrate, a phase shift layer, a first hard mask layer and an opaque layer. The transparent substrate is disposed on the transparent substrate. The first hard mask layer is disposed on the phase shift layer. The phase shift layer has an etching selectivity with respect to the first hard mask layer. The opaque layer is disposed on the first hard mask layer.

There are provided a reflective mask blank in which a fine absorption film pattern is formed even when a high-absorbent material is used as an absorption film of an EUV mask, whereby the shadowing effect can be reduced and electron beam repair etching can be performed and a reflective mask blank for producing the same. A reflective mask blank (10) according to this embodiment includes: a substrate (1); a multi-layer reflective film (2) reflecting an EUV light having a multi-layer structure formed on the substrate (1); a capping layer (3) protecting the multi-layer reflective film (2) formed on the multi-layer reflective film (2); and an absorption film (4) absorbing the EUV light formed on the capping layer (3), in which the absorption film (4) contains 50% by atom or more of elements constituting at least one of tin oxide (SnO) and indium oxide (InO) and contains a material easy to be etched by a fluorine-based gas or a chlorine-based gas.

There are provided a reflective mask blank in which a fine absorption film pattern is formed even when a high-absorbent material is used as an absorption film of an EUV mask, whereby the shadowing effect can be reduced and electron beam repair etching can be performed and a reflective mask blank for producing the same. A reflective mask blank (10) according to this embodiment includes: a substrate (1); a multi-layer reflective film (2) reflecting an EUV light having a multi-layer structure formed on the substrate (1); a capping layer (3) protecting the multi-layer reflective film (2) formed on the multi-layer reflective film (2); and an absorption film (4) absorbing the EUV light formed on the capping layer (3), in which the absorption film (4) contains 50% by atom or more of elements constituting at least one of tin oxide (SnO) and indium oxide (InO) and contains a material easy to be etched by a fluorine-based gas or a chlorine-based gas.

An imprint lithography method includes forming a first imprint pattern on a substrate in a first area and a third area, wherein the third area is spaced apart from the first area, forming a first resist pattern on the substrate on a second area, wherein the second area is adjacent the first and third areas, forming a first pattern in the first and third areas by etching an element under the first imprint pattern using the first imprint pattern and the first resist pattern as an etch barrier, forming a second imprint pattern on the substrate in a second area, forming a second resist pattern on the substrate on the first area and the third area, and forming a second pattern in the second area by etching an element under the second imprint pattern using the second imprint pattern and the second resist pattern as an etch barrier.

An imprint lithography method includes forming a first imprint pattern on a substrate in a first area and a third area, wherein the third area is spaced apart from the first area, forming a first resist pattern on the substrate on a second area, wherein the second area is adjacent the first and third areas, forming a first pattern in the first and third areas by etching an element under the first imprint pattern using the first imprint pattern and the first resist pattern as an etch barrier, forming a second imprint pattern on the substrate in a second area, forming a second resist pattern on the substrate on the first area and the third area, and forming a second pattern in the second area by etching an element under the second imprint pattern using the second imprint pattern and the second resist pattern as an etch barrier.

A photomask assembly may be formed such that stress relief trenches are formed in a pellicle frame of the photomask assembly. The stress relief trenches may reduce or prevent damage to a pellicle that may otherwise result from deformation of the pellicle. The stress relief trenches may be formed in areas of the pellicle frame to allow the pellicle frame to deform with the pellicle, thereby reducing the amount damage to the pellicle caused by the pellicle frame.

The present invention provides a method and apparatus for etching a photomask substrate with enhanced process monitoring, for example, by providing for optical monitoring at certain regions of the photomask to obtain dual endpoints, e.g., etch rate or thickness loss of both a photoresist layer and an absorber layer. By monitoring transmissity of an optical beam transmitted through areas having photoresist layer and etched absorber layer at two different predetermined wavelength, dual process endpoints may be obtained by a signal optical detection.

The present invention provides a method and apparatus for etching a photomask substrate with enhanced process monitoring, for example, by providing for optical monitoring at certain regions of the photomask to obtain dual endpoints, e.g., etch rate or thickness loss of both a photoresist layer and an absorber layer. By monitoring transmissity of an optical beam transmitted through areas having photoresist layer and etched absorber layer at two different predetermined wavelength, dual process endpoints may be obtained by a signal optical detection.

In a method of manufacturing a photo mask, an etching mask layer having circuit patterns is formed over a target layer of the photo mask to be etched. The photo mask includes a backside conductive layer. The target layer is etched by plasma etching, while preventing active species of plasma from attacking the backside conductive layer.

In a method of manufacturing a photo mask, an etching mask layer having circuit patterns is formed over a target layer of the photo mask to be etched. The photo mask includes a backside conductive layer. The target layer is etched by plasma etching, while preventing active species of plasma from attacking the backside conductive layer.