In an embodiment, an apparatus includes an energy source, a support platform for holding a wafer, an optical path extending from the energy source to the support platform, and a photomask aligned such that a patterned major surface of the photomask is parallel to the force of gravity, where the optical path passes through the photomask, where the patterned major surface of the photomask is perpendicular to a topmost surface of the support platform.

A blank mask including a transparent substrate and a light shielding film disposed on the transparent substrate, wherein the light shielding film comprises a transition metal and at least one selected from the group consisting of oxygen and nitrogen, and wherein when an optical density of the light shielding film is measured ten times by a light with a wavelength of 193 nm, a standard deviation of measured optical density is 0.009 or less, is disclosed.

A blank mask including a transparent substrate and a light shielding film disposed on the transparent substrate, wherein the light shielding film comprises a transition metal and at least one selected from the group consisting of oxygen and nitrogen, and wherein when an optical density of the light shielding film is measured ten times by a light with a wavelength of 193 nm, a standard deviation of measured optical density is 0.009 or less, is disclosed.

The present disclosure provides a hardmask structure for preparing a semiconductor structure. The hardmask structure includes a first ashable hardmask layer, a first anti-reflection coating, and a second ashable hardmask layer. The first anti-reflection coating is disposed on the first ashable hardmask layer. The second ashable hardmask layer is disposed on the first anti-reflection coating. A modulus of the first ashable hardmask layer is greater than a modulus of the second ashable hardmask layer.

The present disclosure provides a hardmask structure for preparing a semiconductor structure. The hardmask structure includes a first ashable hardmask layer, a first anti-reflection coating, and a second ashable hardmask layer. The first anti-reflection coating is disposed on the first ashable hardmask layer. The second ashable hardmask layer is disposed on the first anti-reflection coating. A modulus of the first ashable hardmask layer is greater than a modulus of the second ashable hardmask layer.

A photomask includes a reticle substrate, a main pattern disposed on the reticle substrate and defining a photoresist pattern realized on a semiconductor substrate, and anti-reflection patterns adjacent to the main pattern. A distance between a pair of the anti-reflection patterns adjacent to each other is a first length, and a width of at least one of the pair of anti-reflection patterns is a second length. A sum of the first length and the second length is equal to or smaller than a minimum pitch defined by resolution of an exposure process. A distance between the main pattern and the anti-reflection pattern nearest to the main pattern is equal to or smaller than the first length.

A photomask includes a reticle substrate, a main pattern disposed on the reticle substrate and defining a photoresist pattern realized on a semiconductor substrate, and anti-reflection patterns adjacent to the main pattern. A distance between a pair of the anti-reflection patterns adjacent to each other is a first length, and a width of at least one of the pair of anti-reflection patterns is a second length. A sum of the first length and the second length is equal to or smaller than a minimum pitch defined by resolution of an exposure process. A distance between the main pattern and the anti-reflection pattern nearest to the main pattern is equal to or smaller than the first length.

A mask (M) for EUV lithography includes: a substrate (7), a first surface region (A.sub.1) formed by a surface (8a) of a multilayer coating (8) embodied to reflect EUV radiation (27), said surface (8a) facing away from the substrate (7), and a second surface region (A.sub.2) formed by a surface (18a) of a further coating (18) embodied to reflect DUV radiation (28) and to suppress the reflection of EUV radiation (27), said surface (18a) facing away from the substrate (7). The further coating is a multilayer coating (18). Also disclosed are an EUV lithography apparatus that includes such a mask (M) and a method for determining a contrast proportion caused by DUV radiation when imaging a mask (M) onto a light-sensitive layer.

A mask (M) for EUV lithography includes: a substrate (7), a first surface region (A.sub.1) formed by a surface (8a) of a multilayer coating (8) embodied to reflect EUV radiation (27), said surface (8a) facing away from the substrate (7), and a second surface region (A.sub.2) formed by a surface (18a) of a further coating (18) embodied to reflect DUV radiation (28) and to suppress the reflection of EUV radiation (27), said surface (18a) facing away from the substrate (7). The further coating is a multilayer coating (18). Also disclosed are an EUV lithography apparatus that includes such a mask (M) and a method for determining a contrast proportion caused by DUV radiation when imaging a mask (M) onto a light-sensitive layer.

The present disclosure relates to a method and apparatus for mitigating printable native defects in an extreme ultra violet (EUV) mask substrate. In some embodiments, the method is performed by identifying a printable native defect within an EUV mask substrate that violates one or more sizing thresholds. A first section of the EUV mask substrate including the printable native defect is removed to form a concavity within the EUV mask substrate. A multi-layer replacement section that is devoid of a printable native defect is inserted into the concavity.