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.

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.

A method for source mask optimization to increase scanner throughput for a patterning process is described. The method includes computing a multi-variable cost function of design variables that are representative of characteristics of the patterning process. The design variables may include (a) an illumination variable that is characteristic of an illumination system, and (b) a design layout variable that is characteristic of a design layout. The multi-variable cost function may be a function of a throughput of the patterning process. The method further includes reconfiguring the characteristics of the patterning process by adjusting the design variables until a predefined termination condition is satisfied.

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.

A method for determining deviations in a fabrication process, the method including: providing a sample with a layer having a periodic structure fabricated using the fabrication process and intended to cause a corresponding part of the layer to be fully reflective for light having a wavelength in a wavelength range and having an angle of incidence in an angle range; illuminating the sample with light having a wavelength in the wavelength range and an angle of incidence in the angle range; detecting light reflected and/or scattered from the layer of the sample; and determining deviations in the fabrication process from the detected light.

An exposure apparatus includes an illumination optical system for illuminating an original including a periodic pattern, a projection optical system for forming an image of the original on a substrate, a controller configured to cause light from the illumination optical system to be obliquely incident on the original such that a light intensity distribution which is line-symmetric with respect to a line, passing through an origin of a pupil region of the projection optical system and orthogonal to a periodic direction of the periodic pattern, is formed in the pupil region by diffracted light beams including diffracted light of not lower than 2nd-order from the periodic pattern, and to control exposure of the substrate such that each point in a shot region of the substrate is exposed in not less than two focus states.

A method of generating a mask used in fabrication of a semiconductor device includes, in part, selecting a source candidate, generating a process simulation model that includes a defect rate in response to the selected source candidate, performing a first optical proximity correction (OPC) on the data associated with the mask in response to the process simulation model, assessing one or more lithographic evaluation metrics in response to the OPC mask data, computing a cost in response to the assessed one or more lithographic evaluation metrics, and determining whether the computed cost satisfies a threshold condition. In response to the determination that the computed cost does not satisfy the threshold condition, a different source candidate may be selected.

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.

In a method of pattern formation information including a pattern size on a reticle is received. A width of an EUV radiation beam is adjusted in accordance with the information. The EUV radiation beam is scanned on the reticle. A photo resist layer is exposed with a reflected EUV radiation beam from the reticle. An increase of intensity per unit area of the EUV radiation beam on the reticle after the adjusting the width is greater when the width before adjustment is W1 compared to an increase of intensity per unit area of the EUV radiation beam on the reticle after the adjusting the width when the width before adjustment is W2 when W1>W2.

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.