Abstract: 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.

Abstract: A method for determining process window limiting patterns based on aberration sensitivity associated with a patterning apparatus. The method includes obtaining (i) a first set of kernels and a second set of kernels associated with an aberration wavefront of the patterning apparatus and (ii) a design layout to be printed on a substrate via the patterning apparatus; and determining, via a process simulation using the design layout, the first set of kernels, and the second set of kernels, an aberration sensitivity map associated with the aberration wavefront, the aberration sensitivity map indicating how sensitive one or more portions of the design layout are to an individual aberrations and an interaction between different aberrations; determining, based on the aberration sensitivity map, the process window limiting pattern associated with the design layout having relatively high sensitivity compared to other portions of the design layout.

Abstract: Methods for optimizing an aspect of a patterning process based on defects. For example, a method of source and mask optimization of a patterning process includes obtaining a location on a substrate having a threshold probability of having a defect; defining an defect ambit around the location to include a portion of a pattern on the substrate and one or more evaluation points associated with the portion of the pattern; determining a value of a first cost function based on a defect metric associated with the defect; determining a first guide function for the first cost function, wherein the first guide function is associated with a performance metric of the patterning process at the one or more evaluation locations within the defect ambit; and adjusting a source and/or a mask characteristic based on the value of the first cost function, and the first guide function.

Abstract: A diffraction pattern guided source mask optimization (SMO) method that includes determining a source variable region from a diffraction pattern. The source variable region corresponds to one or more areas of a diffraction pattern in a pupil for which one or more pupil variables are to be adjusted. The source variable region in the diffraction pattern includes a plurality of pixels in an image of a selected region of interest in the diffraction pattern. Determining the source variable region can include binarization of the plurality of pixels in the image such that individual pixels are either included in the source variable region or excluded from the source variable region. The method can include adjusting the one or more pupil variables for the one or more areas of the pupil that correspond to the source variable region; and rendering a final pupil based on the adjusted one or more pupil variables.

Abstract: Systems, methods, and computer programs for increasing a contrast for a lithography system are disclosed. In one aspect, a method of optimizing a process for imaging a feature on a substrate using a photolithography system is disclosed, the method including obtaining an optical spectrum of a light beam for the imaging, wherein the light beam includes pulses having a plurality of different wavelengths, and narrowing the optical spectrum of the pulses of the light beam for the imaging to improve a quality metric of the imaging.

Abstract: Apparatuses and techniques for suppressing a zeroth order portion of a configured radiation beam. In some embodiments, an extreme ultraviolet (EUV) lithographic apparatus for forming an image on a substrate by use of an EUV radiation beam that is configured by a patterning device comprising a pattern of reflective regions and partially reflective regions, wherein the partially reflective regions are configured to suppress and apply a phase shift to a portion of the EUV radiation beam, may include a projection system. The projection system may be configured to suppress a zeroth order portion of a configured EUV radiation beam, and direct an unsuppressed portion of a configured EUV radiation beam towards a substrate to form an image on the substrate.

Abstract: A method for source mask optimization with a lithographic projection apparatus. The method includes determining a multi-variable source mask optimization function using a plurality of tunable design variables for an illumination system of the lithographic projection apparatus, a projection optics of the lithographic projection apparatus to image a mask design layout onto a substrate, and the mask design layout. The multi-variable source mask optimization function may account for imaging variation across different positions in an exposure slit corresponding to different stripes of the mask design layout exposed by a same slit position of the exposure apparatus. The method includes iteratively adjusting the plurality of tunable design variables in the multi-variable source mask optimization function until a termination condition is satisfied.

Abstract: 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.

Abstract: A patterning device, includes: an absorber layer on a patterning device substrate; and a reflective or transmissive layer on the patterning device substrate, wherein the absorber layer and the reflective or transmissive layer together define a pattern layout having a main feature and an attenuated sub-resolution assist feature paired with the main feature, wherein: the main feature is configured to generate, upon transferring the device pattern to a layer of patterning material on a substrate, the main feature in the layer of patterning material, and upon the transferring the pattern to the layer of patterning material, the attenuated sub-resolution assist feature is configured to avoid generating a feature in the layer of patterning material and to produce a different radiation intensity than the main feature.

Abstract: A method for determining a wavefront parameter of a patterning process. The method includes obtaining a reference performance (e.g., a contour, EPE, CD) of a reference apparatus (e.g., a scanner), a lens model for a patterning apparatus configured to convert a wavefront parameter of a wavefront to actuator movement, and a lens fingerprint of a tuning apparatus (e.g., a to-be-matched scanner). Further, the method involves determining the wavefront parameter (e.g., a wavefront parameter such as tilt, offset, etc.) based on the lens fingerprint of the tuning apparatus, the lens model, and a cost function, wherein the cost function is a difference between the reference performance and a tuning apparatus performance.

Abstract: Systems, methods, and computer programs for increasing a depth of focus for a lithography system are disclosed. In one aspect, a method includes providing an optical spectrum, a mask pattern, and a pupil design, that together are configured to provide the lithography system with a depth of focus. The method also includes iteratively varying the optical spectrum and an assist feature in the mask pattern to provide a modified optical spectrum and a modified mask pattern that increases the depth of focus. The method further includes configuring a component of the lithography system based on the modified optical spectrum and the modified mask pattern that increases the depth of focus.

Abstract: 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.

Abstract: A patterning device, includes: an absorber layer on a patterning device substrate; and a reflective or transmissive layer on the patterning device substrate, wherein the absorber layer and the reflective or transmissive layer together define a pattern layout having a main feature and an attenuated sub-resolution assist feature paired with the main feature, wherein: the main feature is configured to generate, upon transferring the device pattern to a layer of patterning material on a substrate, the main feature in the layer of patterning material, and upon the transferring the pattern to the layer of patterning material, the attenuated sub-resolution assist feature is configured to avoid generating a feature in the layer of patterning material and to produce a different radiation intensity than the main feature.

Abstract: A method for optimization to increase lithographic apparatus throughput for a patterning process is described. The method includes providing a baseline dose for an EUV illumination and an initial pupil configuration, associated with a lithographic apparatus. The baseline dose and the initial pupil configuration are configured for use with a dose anchor mask pattern and a corresponding dose anchor target pattern for setting an illumination dose for corresponding device patterns of interest. The method includes biasing the dose anchor mask pattern relative to the dose anchor target pattern; determining an acceptable lower dose for the biased dose anchor mask pattern and the initial pupil configuration; unbiasing the dose anchor mask pattern relative to the dose anchor target pattern; and determining a changed pupil configuration and a mask bias for the device patterns of interest based on the acceptable lower dose and the unbiased dose anchor mask pattern.

Abstract: A method for optimizing a patterning device pattern, the method including obtaining an initial design pattern having a plurality of polygons, causing at least some of the polygons to be effectively connected with each other, placing evaluation features outside the boundaries of the polygons, and creating a patterning device pattern spanning across the connected polygons based on the evaluation features.

Abstract: 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 illuminator and projection optics, the method including: computing a multi-variable cost function of a plurality of design variables that are characteristics of the lithographic process, at least some of the design variables being characteristics of the illumination produced by the illuminator and of the design layout, wherein the multi-variable cost function is a function of a three-dimensional resist profile on the substrate, or a three-dimensional radiation field projected from the projection optics, or both; and reconfiguring one or more characteristics of the lithographic process by adjusting the design variables until a predefined termination condition is satisfied.

Abstract: Several methods of reducing one or more pattern displacement errors, contrast loss, best focus shift, tilt of a Bossung curve of a portion of a design layout used in a patterning process for imaging that portion onto a substrate using a lithographic apparatus. The methods include determining or adjusting one or more characteristics of one or more assist features using the one or more rules based on one or more parameters selected from a group consisting of: one or more characteristics of one or more design features in the portion, one or more characteristics of the patterning process, one or more characteristics of the lithographic apparatus, and/or a combination selected from the foregoing.

Abstract: A method to determine a mask pattern for a patterning device. The method includes obtaining a target pattern to be printed on a substrate, an initial continuous tone image corresponding to the target pattern, a binarization function (e.g., a sigmoid, an arctan, a step function, etc.) configured to transform the initial continuous tone image, and a process model configured to predict a pattern on the substrate from an output of the binarization function; and generating a binarized image having a mask pattern corresponding to the initial continuous tone image by iteratively updating the initial continuous tone image based on a cost function such that the cost function is reduced. The cost function (e.g., EPE) determines a difference between a predicted pattern determined by the process model and the target pattern.

Abstract: The embodiments herein disclose a method and apparatus for mixing sludge retained in a digester. A jet nozzle assembly for mixing contents of a vessel is used. The jet nozzle assembly having a central outlet pipe terminating at a jet nozzle, a low pressure nozzle assembly disposed concentrically about the central outlet pipe, the low pressure low pressure nozzle having a plurality of openings disposed circumferentially about the low pressure nozzle assembly. The plurality of openings are an axial distance from the outlet jet nozzle.

Abstract: Disclosed herein are several methods of reducing one or more pattern displacement errors, contrast loss, best focus shift , tilt of a Bossung curve of a portion of a design layout used in a lithographic process for imaging that portion onto a substrate using a lithographic apparatus. The methods include adjusting an illumination source of the lithographic apparatus, placing assist features onto or adjusting positions and/or shapes existing assist features in the portion. Adjusting the illumination source and/or the assist features may be by an optimization algorithm.