Systems and methods are provided for adjusting a fluid dispenser for depositing drops of formable material. According to embodiments, a system obtains an image of a substrate including a film formed on the substrate by curing the formable material deposited by a first dispenser and a second dispenser. Intensity information is obtained for pixels of the image and a difference is determined between intensity values from a portion of the substrate on which the first dispenser deposited drops and intensity values from a portion on which the second dispenser deposited drops, the intensity values corresponding to a region of the substrate associated with a target thickness. Adjustments based on the intensity values are made to change a drop volume and a drop density for nozzles of the first dispenser and nozzles of the second dispenser.

Disclosed is a program code and a non-transitory computer readable medium including the program code, in which the program code, when executed by a processor, causes an apparatus including the processor to perform operations of selecting a plurality of target patterns from a mask layout, generating an aerial image based on a source system including a plurality of point sources and the mask layout, constructing an objective function based on a plurality of NILS values corresponding to the plurality of target patterns in the aerial image, optimizing the source system such that the objective function has a maximum value, and outputting an optimized source system, and the optimized source system includes a combination of a plurality of effective factors corresponding to the plurality of point sources.

A method may include illuminating an overlay target of a sample with one or more broadband illumination beams from one or more broadband illumination sources. The overlay target may include one or more meta-lens feature sets. Each meta-lens feature set may include one or more first features having a coarse pitch and one or more second features having a fine pitch. The one or more first features and the one or more second features of each meta-lens feature set may operate as a meta-lens array to generate a periodic distribution of light at a measurement plane. The method may further include generating one or more images of the periodic distribution of light at the measurement plane. The method may further include generating an overlay measurement of the sample based on the one or more images of the periodic distribution of light at the measurement plane.

The invention relates to a computer implemented method for generating an aerial image of a model of a photolithography mask under illumination by incident electromagnetic waves, the method comprising: a) Approximately simulating the propagation of the incident electromagnetic waves within a first section of the photolithography mask that comprises multiple structures; b) Simulating the propagation of the simulated electromagnetic waves from step a) within a second section of the photolithography mask analytically or numerically; c) Simulating a representation of an electromagnetic near field of the model of the photolithography mask by propagating the simulated electromagnetic waves from step b) to a near field plane; and d) Generating an aerial image of the photolithography mask.

A method to determine a performance indicator indicative of alignment performance of a processed substrate. The method includes obtaining measurement data including a plurality of measured position values of alignment marks on the substrate and calculating a positional deviation between each measured position value and a respective expected position value. These positional deviations are used to determine a directional derivative between the alignment marks, and the directional derivatives are used to determine at least one directional derivative performance indicator.

Method of spatially aligning a patterning device and a substrate, wherein the patterning device and the substrate are separated by an optical path including one or more moveable optical components, the method including: projecting a radiation beam from the patterning device along the optical path; performing a displacement of the one or more moveable optical components along a predetermined trajectory; determining an optical characteristic of the radiation beam as received by a sensor on a substrate table supporting the substrate at a plurality of instants during the displacement of the one or more moveable optical components; and spatially aligning the patterning device and the substrate based on the optical characteristic as determined at the plurality of instants.

A computer implemented method for inspecting a photolithography mask to predict defects in wafers, the method comprising: providing a model of the photolithography mask comprising one or more target features and one or more sub-resolution assist features, the photolithography mask being configured for printing of the one or more target features onto a wafer in a printing process using a photolithography system; identifying one or more critical locations in the model of the photolithography mask by verifying a predefined constraint concerning the target features and/or the sub-resolution assist features; generating an aerial image of the photolithography mask comprising the one or more identified critical locations by applying a model of the photolithography system to the photolithography mask; predicting defects in wafers by comparing the one or more identified critical locations of the aerial image to one or more corresponding locations of a reference image. Also disclosed are a computer-readable medium, a computer program product and corresponding systems for the prediction of defects in wafers and wafer-less process window qualification.

To simulate illumination and imaging properties of an optical production system when illuminating and imaging an object by use of an optical measurement system of a metrology system, a pupil stop of the optical measurement system is initially provided for the purpose of specifying at least one measurement illumination setting created by use of the pupil stop. Measurement aerial images I.sub.meas are recorded in an image plane of an imaging optics unit of the optical measurement system for different displacement positions of the object perpendicular to an object plane (xy) for the at least one measurement illumination setting. A complex mask transfer function M is reconstructed from the recorded measurement aerial images I.sub.meas. A 3-D aerial image I.sub.sim of the optical production system is determined from the reconstructed mask transfer function M and a specified illumination setting .sub.target of the optical production system as the result of the simulation method. The reconstruction includes the fact that the optical production system to be simulated comprises a production illumination setting BP.sub.y1, BPy.sub.2) to be simulated, with the latter varying in the object displacement direction (y). This yields an improved simulation method.

Disclosed is a metrology method. The method comprises illuminating a target comprising one or more sub-targets on a substrate using underfilled illumination such that an illumination beam profile underfills each of said one or more sub-targets; capturing scattered radiation resultant from said illuminating the target; imaging the scattered radiation at a detection image plane to obtain an image; and determining a parameter of interest from the imaged scattered radiation.

A measuring method for measuring distortion of a substrate includes capturing images of a plurality of partial regions of a pattern formed in a device region of the substrate, measuring a position of the pattern based on the images acquired by the image capturing, and processing of determining a period of the pattern based on the images acquired by the image capturing, and determining distortion in the region of the substrate where the pattern is formed, based on the determined period and a measurement result acquired in the measuring.