The present disclosure provides one embodiment of an IC method that includes receiving an IC design layout including a first main feature and inserting a first plurality of scattering bars in the IC design layout to form a first circular pattern of scattering bars around the first main feature. The first main feature is positioned at a center portion of the first circular pattern of scattering bars.

A method of characterizing a lithographic mask type uses a mask having thereon test pattern units of linear features at different orientations. The mask is exposed, rotated by angle, exposed again, rotated by a further angle, exposed, etc. The printed features are measured to determine one or more characteristics of the mask. The method can be used to model shadowing effects of a EUV mask with a thick absorber illuminated at an angle.

Methods for reducing reticle transmission differences and for optimizing layer placement for overlay in MTRs and CTRs are disclosed. Embodiments include providing a reticle having a prime area and a frame area surrounding the prime area; determining RT differences across the prime area; and providing RT adjustment structures on the reticle to decrease the RT differences. Other embodiments include grouping multiple layers of a semiconductor production flow, the layers for each group having an RT difference less than a predetermined value; and placing the layers on plural ordered reticles of a reticle set, each reticle having multiple image fields, by selecting, for each reticle, layers from a single group and optimizing placement of the layers for overlay. Other embodiments include selectively rotating image fields on a reticle having multiple image fields to improve overlay, or optimizing placement of DDLs on CTRs by placing each design orientation on a different reticle.

Aspects of the invention relate to techniques for determining pattern optical similarity in lithography. Optical kernel strength values for a first set of layout features and a second set of layout features are computed first. Based on the optical kernel strength values, optical similarity values between the first set of layout features and the second set of layout features are then determined. Subsequently, calibration weight values for the first set of layout features may be determined based on the optical similarity values, which, along with the first set of layout features, may be employed to calibrate lithography process model parameters.

The invention relates to a method for producing a structure in a lithographic material, wherein the structure in the lithographic material is defined by means of a writing beam of an exposure device, in that a plurality of partial structures are written sequentially, wherein for writing the partial structures a write field of the exposure device is displaced and positioned sequentially and that a partial structure is written in the write field in each case, and wherein for positioning of the write field a reference structure is detected by means of an imaging measuring device. For calibration of the write field in the respectively positioned write field, before, during or after writing a partial structure, at least one reference structure element assigned to this partial structure is produced in the lithographic material with the writing beam, wherein the reference structure element after the displacement of the write field is detected by means of the imaging measuring device for writing a further partial structure.

A method including: simulating an image or characteristics thereof, using characteristics of a design layout and of a patterning process, determining deviations between the image or characteristics thereof and the design layout or characteristics thereof; aligning a metrology image obtained from a patterned substrate and the design layout based on the deviations, wherein the patterned substrate includes a pattern produced from the design layout using the patterning process; and determining a parameter of a patterned substrate from the metrology image aligned with the design layout.

Embodiments disclosed herein relate to an exposure pattern alteration software application which manipulates exposure polygons having lines with angles substantially close to angles of symmetry of a hex close pack arrangement, which suffer from long jogs. Long jogs present themselves as high edge placement error regions. As such, the exposure pattern alteration software application provides for line wave reduction by serrating polygon edges at affected angles to reduce edge placement errors during maskless lithography patterning in a manufacturing process.

The disclosure provides a control device for controlling at least one manipulator of a microlithographic projection lens by generating a travel command, which defines a change to be undertaken, of an optical effect of at least one optical element of the projection lens by manipulating a property of the optical element via the at least one manipulator along a travel. The control device is configured to generate the travel command for the at least one manipulator from a state characterization of the projection lens by optimizing a merit function. Here, the merit function includes a linear combination of at least two exponential expressions, a setting of the at least one manipulator defining the manipulation of the property of the optical element is represented via a travel variable and the respective base of the at least two exponential expressions contains a function of the travel variable.

A method for ascertaining distortion properties of an optical system in a measurement system for microlithography is provided, wherein the optical system images at least one structure to be measured into a measurement image. In accordance with one aspect, a method according to the invention comprises the following steps: measuring the field-dependent image aberrations of the optical system; determining a first distortion pattern present in the first image field generated by the optical system during measurement of at least one predefined structure; carrying out an optical forward simulation for the predefined structure taking account of the field-dependent image aberrations measured previously, with a second image field being generated; determining a second distortion pattern for the second image field generated previously; and ascertaining the structure-independent distortion properties of the optical system by calculating a third distortion pattern as the difference between the first distortion pattern and the second distortion pattern.

A method includes measuring a three-dimensional topography of a feature of a pattern of a lithography patterning device and calculating from the measurements wavefront phase information caused by the three-dimensional topography of the pattern.