A method includes: receiving a photomask; patterning a wafer by directing a first radiation beam to the wafer through the photomask at a first tilt angle; and inspecting the photomask. The inspecting includes: directing a second radiation beam to the photomask at a second tilt angle greater than the first tilt angle; receiving a third radiation beam reflected from the photomask; and generating an image of the photomask according to the third radiation beam.

A method includes: receiving a photomask; patterning a wafer by directing a first radiation beam to the wafer through the photomask at a first tilt angle; and inspecting the photomask. The inspecting includes: directing a second radiation beam to the photomask at a second tilt angle greater than the first tilt angle; receiving a third radiation beam reflected from the photomask; and generating an image of the photomask according to the third radiation beam.

Methods of fabricating lithographic masks include performing mask process correction (MPC) on a mask tape out (MTO) design layout. Performing MPC may include identifying a plurality of unit cells (each being iterated in the MTO design layout and including a plurality of curve patterns), and performing model-based MPC on at least one of the plurality of unit cells. These methods may further include performing electron beam exposure based on the MTO design layout on which the MPC is performed. The performing model-based MPC on at least one of the plurality of unit cells may be based on at least one of an aspect ratio, sizes, curvatures of curved edges, density, and a duty of the plurality of curve patterns.

Methods of fabricating lithographic masks include performing mask process correction (MPC) on a mask tape out (MTO) design layout. Performing MPC may include identifying a plurality of unit cells (each being iterated in the MTO design layout and including a plurality of curve patterns), and performing model-based MPC on at least one of the plurality of unit cells. These methods may further include performing electron beam exposure based on the MTO design layout on which the MPC is performed. The performing model-based MPC on at least one of the plurality of unit cells may be based on at least one of an aspect ratio, sizes, curvatures of curved edges, density, and a duty of the plurality of curve patterns.

Disclosed is an object table for holding an object, comprising: an electrostatic clamp arranged to clamp the object on the object table; a neutralizer arranged to neutralize a residual charge of the electrostatic clamp; a control unit arranged to control the neutralizer, wherein the residual charge is an electrostatic charge present on the electrostatic clamp when no voltage is applied to the electrostatic clamp.

A mask inspection apparatus includes an image acquisition mechanism that acquires an optical image of the pattern by making an inspection light incident on an EUV mask and detecting a reflection inspection light reflected from the EUV mask, in a state where the relation between the incident direction of the inspection light used for inspecting the pattern formed on the EUV mask, and the arrangement direction of the EUV mask serving as the inspection substrate is matched with the relation between the incident direction of the EUV light on the EUV mask, and the arrangement direction of the EUV mask in the EUV exposure apparatus.

Methods for repairing a defect of a lithographic mask with a particle beam are described. One such method can comprise the following steps: Processing the defect with the particle beam with a first set of processing parameters; processing the defect with the particle beam with a second set of processing parameters; wherein at least one parameter from the first set of processing parameters differs from the second set of processing parameters.

Methods for repairing a defect of a lithographic mask with a particle beam are described. One such method can comprise the following steps: Processing the defect with the particle beam with a first set of processing parameters; processing the defect with the particle beam with a second set of processing parameters; wherein at least one parameter from the first set of processing parameters differs from the second set of processing parameters.

The present invention relates to a method for setting at least one side wall angle of at least one pattern element of a photolithographic mask including the steps of: (a) providing at least one precursor gas; (b) providing at least one massive particle beam which induces a local chemical reaction of the at least one precursor gas; and (c) altering at least one parameter of the particle beam and/or a process parameter during the local chemical reaction in order to set the at least one side wall angle of the at least one pattern element.

The present invention relates to a method for setting at least one side wall angle of at least one pattern element of a photolithographic mask including the steps of: (a) providing at least one precursor gas; (b) providing at least one massive particle beam which induces a local chemical reaction of the at least one precursor gas; and (c) altering at least one parameter of the particle beam and/or a process parameter during the local chemical reaction in order to set the at least one side wall angle of the at least one pattern element.