An apparatus comprising a multilayer structure configured to reflect electromagnetic radiation. The apparatus comprises a sensor configured to detect an angular distribution of the electromagnetic radiation after reflection from the multilayer structure. The apparatus comprises a processor configured to generate a first function at least partially based on the angular distribution of the electromagnetic radiation detected by the sensor. The processor is configured to compare the first function to a plurality of known functions associated with a plurality of known angular reflectivity profiles to identify a second function from the plurality of known functions that is most similar to the first function. The processor is configured to determine an angular reflectivity profile of the multilayer structure at least partially based on a known angular reflectivity profile that is associated with the second function.

A mirror element (20) having a mirror surface (26) with an aspherical target region (22) and an extension region (28) adjoining an edge (24) of the target region (22) is disclosed, wherein the edge (24) is describable by an at least twice continuously differentiable closed curve (b), wherein the target region (22) has a respective edge curvature at each edge point(s) located on the curve, and wherein, when proceeding from the edge point(s) in a profile direction transverse to the edge (24), the extension region (28) has a curvature profile, which has no more than one local extremum and the absolute values of the curvatures of which are less than twice the absolute value of the edge curvature. Also disclosed are a lithography system (1) including a mirror element (20) and a method for providing a mirror element (20).

Methods, apparatuses, and software are disclosed for optimization of a source and/or mask as used in lithographic manufacturing and patterning processes. One method includes determining a first pupil having a central obscuration (CO), determining a diffraction order (DO) based on a target design and a mask model, determining a first diffraction pattern (DP) based on the DO and the first pupil, the first DP including overlapping regions of diffracted light, determining a second DP based on the DO and the first pupil, and determining an initial pupil based on the first DP and the second DP, the initial pupil including at least some of the overlapping regions.

The method for optimizing a light source in integrated circuit manufacturing, includes following steps: S1, providing an initial light source; S2, performing region segmentation according to light intensity distribution of the initial light source to obtain a plurality of sub light source regions; S3, providing at least two matching patterns and matching them with each sub light source region to obtain at least two matching results corresponding to each sub light source region; S4, performing calculating based on the at least two matching results and each sub light source region to obtain a best matching pattern corresponding to each sub light source region; and S5, generating a light source to be optimized based on the best matching pattern corresponding to each sub light source region.

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 is presented for correcting a photomask includes receiving a target design layout of a semiconductor device. The method includes inferring, by a processor, a mask bias by inputting into a first machine learning model an optical feature value, a geometrical feature value, and a resist feature value of a mask layout based on the target design layout. The processor generates a predicted pattern by incorporating the mask bias in the mask layout, and by comparing the predicted pattern with the target design layout the processor then corrects the mask layout based on a result of the comparison between the predicted pattern and the target design layout.

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.

A method for optimizing a mask absorption material based on a surface plasmon multilayer structure. The method comprises: S1) constructing a plurality of structures for a multilayer superlens; S2) simulating light transmission in each structure of the plurality of structures through software modelling to obtain an image contrast of a pattern formed at a central region of a photoresist coated on a base layer; and S3) determining the parameter of the layer of the plurality of absorption masks for a structure of the multilayer superlens based on the image contrast. In comparison with the conventional technology, the above method is based on the multilayer structure and optimizes three-dimensional parameters of the absorption mask(s). Experiments have shown that the above method has a significant effect on improving the resolution and the image contrast of the multilayer structure.

An operating method of an extreme ultraviolet (EUV) lithography device includes obtaining a target image, obtaining position matching information between field facets included in a field facet mirror (FFM) and pupil facets included in a pupil facet mirror (PFM), obtaining information of a pupil intensity of the pupil facets of the PFM, and performing rendering of one or more individually selectable pupil facets of the PFM based on the position matching information, the target image, and the pupil intensity.

A method of operating at least one solid-state actuator in a microlithographic projection exposure apparatus comprises the following steps: requesting a target variable for the at least one solid-state actuator; ascertaining a control variable using a stored or storable correction model, the correction model comprising a correction function for creep; and actuating the at least one solid-state actuator using the control variable and switching the at least one solid-state actuator from a switched-off state into a switched-on state by feeding energy from an energy source.