A method to improve a lithographic process of processing a portion of a design layout onto a substrate using a lithographic apparatus, the method including: adjusting a first processing parameter among processing parameters of the lithographic process to cause the processing to be more tolerant to perturbations of at least one of the processing parameters during processing; and adjusting a second processing parameter among processing parameters of the lithographic process to cause the processing to be more tolerant to perturbations of at least one of the processing parameters during processing.

A simulation apparatus has: a first processing part configured to obtain a value of a parameter in a first set relating to the forming of the pattern; a second processing part configured to obtain a value of a parameter in a second set that is at least partially same as the parameter in the first set and relating to the forming of the pattern; and an integration processing part configured to evaluate, based on the value of the parameter in the first set and the value of the parameter in the second set, a state of the pattern formed on the substrate and a forming condition when the pattern is formed, and to determine based on the result of the evaluation whether or not to make at least one of the first processing part and the second processing part recalculate the value of the parameter in the corresponding set.

An embodiment of the invention may include a method for ensuring semiconductor design integrity. The method may include analyzing a photomask design for a semiconductor circuit. The photomask may include an electrical design necessary for the operation of the semiconductor circuit, and white space, which has no electrical design. The method may include inserting an optical design into the white space of the photomask design for the semiconductor circuit. The optical design may have known optical patterns for validating the semiconductor circuit design. In an embodiment of the invention, the optical design may be physically isolated from the electrical design. In another embodiment of the invention, the optical design may comprise one or more photomask layers and overlay the electrical design. In another embodiment of the invention, the optical design may comprise covershapes.

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.

In one embodiment, a substrate processing control apparatus includes a position information acquiring module configured to acquire information about a position of a first pattern that is formed in a substrate for a photomask to change an applied stress to the substrate or a transmittance of the substrate. The apparatus further includes a position determining module configured to determine, in accordance with the information about the position of the first pattern, a position of a second pattern to be formed in the substrate to change the applied stress to the substrate or the transmittance of the substrate.

The present invention relates to methods and systems for designing gauge patterns that are extremely sensitive to parameter variation, and thus robust against random and repetitive measurement errors in calibration of a lithographic process utilized to image a target design having a plurality of features. The method may include identifying most sensitive line width/pitch combination with optimal assist feature placement which leads to most sensitive CD (or other lithography response parameter) changes against lithography process parameter variations, such as wavefront aberration parameter variation. The method may also include designing gauges which have more than one test patterns, such that a combined response of the gauge can be tailored to generate a certain response to wavefront-related or other lithographic process parameters. The sensitivity against parameter variation leads to robust performance against random measurement error and/or any other measurement error.

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.

A method to improve a lithographic process of imaging a portion of a design layout onto a substrate using a lithographic apparatus, the method including: computing a multi-variable cost function, the multi-variable cost function being a function a plurality of design variables that represent characteristics of the lithographic process; and reconfiguring one or more of the characteristics of the lithographic process by adjusting one or more of the design variables until a certain termination condition is satisfied; wherein a bandwidth of a radiation source of the lithographic apparatus is allowed to change during the reconfiguration.

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.