A method includes measuring properties of a three-dimensional topography of a lithographic patterning device, the patterning device including a pattern and being constructed and arranged to produce a pattern in a cross section of a projection beam of radiation in a lithographic projection system, calculating wavefront phase effects resulting from the measured properties, incorporating the calculated wavefront phase effects into a lithographic model of the lithographic projection system, and determining, based on the lithographic model incorporating the calculated wavefront phase effects, parameters for use in an imaging operation using the lithographic projection system.

A mask includes a plurality of line patterns provided on a substrate, the plurality of line patterns each including a line comprising a plurality of first layers and a plurality of second layers alternately stacked on the substrate. The lines of the plurality of line patterns extend in a first direction and the lines of the plurality of line patterns are spaced in a second direction crossing the first direction. A line of one of the plurality of line patterns has a first portion and a second portion on a side of the first portion in the first direction, the first portion wider than the second portion in the second direction.

A mask includes a plurality of line patterns provided on a substrate, the plurality of line patterns each including a line comprising a plurality of first layers and a plurality of second layers alternately stacked on the substrate. The lines of the plurality of line patterns extend in a first direction and the lines of the plurality of line patterns are spaced in a second direction crossing the first direction. A line of one of the plurality of line patterns has a first portion and a second portion on a side of the first portion in the first direction, the first portion wider than the second portion in the second direction.

A EUV mask comprises a low thermal expansion material (LTEM) substrate, a reflective multi-layer (ML) over the LTEM substrate, and a patterned absorber layer over the reflective ML. The reflective ML includes a defect. The EUV mask further comprises a mark associated with the defect. The mark is one of: a deposit over the patterned absorber layer at a distance offset from the defect, and a cavity into the patterned absorber layer in an area over the defect.

A EUV mask comprises a low thermal expansion material (LTEM) substrate, a reflective multi-layer (ML) over the LTEM substrate, and a patterned absorber layer over the reflective ML. The reflective ML includes a defect. The EUV mask further comprises a mark associated with the defect. The mark is one of: a deposit over the patterned absorber layer at a distance offset from the defect, and a cavity into the patterned absorber layer in an area over the defect.

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.

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.

The present disclosure provides a photomask and a method for repairing a photomask. The photomask includes a substrate, a reflective multi-layer stack over the substrate, a capping layer over the reflective multi-layer stack, an absorber layer over the capping layer, a first patch layer in direct contact with the absorber layer, and a second patch layer over a surface of the first patch layer.

The present disclosure provides a photomask and a method for repairing a photomask. The photomask includes a substrate, a reflective multi-layer stack over the substrate, a capping layer over the reflective multi-layer stack, an absorber layer over the capping layer, a first patch layer in direct contact with the absorber layer, and a second patch layer over a surface of the first patch layer.

The present invention refers to a method and an apparatus for determining positions of a plurality of pixels to be introduced into a substrate of a photolithographic mask by use of a laser system, wherein the pixels serve to at least partly correct one or more errors of the photolithographic mask. The method comprises the steps: (a) obtaining error data associated with the one or more errors; (b) obtaining first parameters of an illumination system, the first parameters determining an illumination of the photolithographic mask of the illumination system when processing a wafer by illuminating with the illumination system using the photolithographic mask; and (c) determining the positions of the plurality of pixels based on the error data and the first parameters.