An illumination optical unit for EUV projection lithography serves for obliquely illuminating an illumination field, in which an object field of a downstream imaging catoptric optical unit and a reflective object to be imaged can be arranged. A pupil generating device of the illumination optical unit is embodied so that an illumination pupil results, which brings about a dependency of an imaging telecentricity against a structure variable of the object to be imaged. This dependency is such that a dependency of the imaging telecentricity against the structure variable of the object to be imaged on account of interaction of the oblique illumination with structures of the object to be imaged is at least partly compensated for. An optical system for EUV projection lithography also has an imaging catoptric optical unit alongside an illumination optical unit and can additionally have a wavefront manipulation device.

Methods of determining, and using, a patterning process model that is a machine learning model. The process model is trained partially based on simulation or based on a non-machine learning model. The training data may include inputs obtained from a design layout, patterning process measurements, and image measurements.

A method to improve a lithographic process for imaging a portion of a patterning device pattern onto a substrate using a lithographic projection having an illumination system and projection optics, the method including: (1) obtaining a simulation model that models projection of radiation by the projection optics, wherein the simulation model models an effect of an obscuration in the projection optics, and configuring, based on the model, the portion of the patterning device pattern, and/or (2) obtaining a simulation model that models projection of radiation by the projection optics, wherein the simulation model models an anamorphic demagnification of radiation by the projection optics, and configuring, based on the model, the portion of the patterning device pattern taking into account an anamorphic manufacturing rule or anamorphic manufacturing rule ratio.

An optimization method for a mask pattern optical transfer includes steps as follows: First, a projection optical simulation is performed to obtain an optimal pupil configuration scheme corresponding to a virtual mask pattern. Next, a position scanning is performed to change the optimal pupil configuration scheme, so as to generate a plurality of adjusted pupil configuration schemes. A mask pattern transfer simulation is performed to obtain a plurality of pupil configuration schemes-critical dimension relationship data corresponding to the virtual mask pattern. Subsequently, an actual pupil configuration scheme suitable for an actual mask pattern is selected according to the plurality of pupil configuration schemes-critical dimension relationship data, and upon which an actual mask pattern transfer is performed.

A method including obtaining a selected component of optical aberration of or for a lithography apparatus, under a processing condition; computing an approximate of a cost function, based on the selected component; and producing an adjustment of the lithography apparatus or a patterning process that uses the lithography apparatus, based on the approximate of the cost function.

Method and system configured to reduce or even nullify the degradation of images created by the projector tool turns on the optimization of the pattern-imaging by adjusting parameters and hardware of the projector to judiciously impact the placement of various image edges at different locations in the image field. Adjustments to the projector (exposure tool) include a change of a setup parameter of the exposure tool and/or scanning synchronization and/or a change of a signature of the optical system of the exposure tool determined as a result of minimizing the pre-determined cost function(s) that are parts of a comprehensive edge-placement error model.

A method for improving a lithographic process for imaging a portion of a design layout onto a substrate using a lithographic apparatus, the method including: obtaining a first source of the lithographic apparatus; classifying the first source into a class among a plurality of possible classes, based on one or more numerical characteristics of the first source, using a machine learning model, by a computer; determining whether the class is among one or more predetermined classes; only when the class is among the one or more predetermined classes, adjusting one or more source design variables to obtain a second source.

An embodiment of the invention may include a semiconductor structure for ensuring semiconductor design integrity. The semiconductor structure may include an electrical circuit necessary for the operation of the semiconductor circuit and white space having no electrical circuit. The semiconductor structure may include an optical pattern used for validating the semiconductor circuit design formed in the white space of the electrical circuit. In an embodiment of the invention, the optical pattern may include one or more deposition layers. In an embodiment of the invention, the optical pattern may include covershapes. In an embodiment of the invention, the optical pattern may be physically isolated from the electrical circuit. The optical pattern may include a Moir pattern.

Methods for configuring a patterning process based on results of another patterning process is described. The method includes obtaining a first set of contours by simulating a first patterning process using a design layout in a first orientation. The contours satisfy a design specification associated with the design layout and correspond to a first set of process window conditions. A second patterning process is configured based on a second orientation of the design layout, the first set of process window conditions and the first set of contours. The second patterning process is associated with one or more design variables (e.g., illumination, mask pattern) that affect a second set of contours. The configuring includes adjusting one or more design variables until the second set of contours are within a desired matching threshold with the first set of contours.

A method to improve a lithographic process for imaging a portion of a design layout onto a substrate using a lithographic projection apparatus having an illumination system and projection optics, the method including: obtaining an illumination source shape and a mask defocus value; optimizing a dose of the lithographic process; and optimizing the portion of the design layout for each of a plurality of slit positions of the illumination source.