Abstract: A computer is programmed to perform lithography simulation at a number of locations in a transverse direction relative to a length of a feature of an IC design, to obtain simulated intensities at the locations. The computer is further programmed to determine constants of a predetermined formula that models a trend of the simulated intensities as a function of distance (in the transverse direction), by curve-fitting. The computer is also programmed to compute a value (“CD predictor”) based on the just-determined constants, the formula and a known threshold intensity for a given position along the feature's length. The just-described process, of lithography-simulation, followed by curve-fitting, followed by CD predictor computation, is repeatedly performed to obtain a number of CD predictors at a corresponding number of positions along the feature's length. The CD predictors are used to identify a position of a critical dimension, for use in, for example, layout verification.

Abstract: A method for performing layout verification involves identifying feature centerlines in a mask layout, and then performing lithography simulation along the centerlines to generate a set of intensity distributions. At each local maxima or minima in the intensity distributions, further lithography simulation can be performed to determine an exposure pattern width at those local maxima/minima (check positions). The exposure pattern widths can then be evaluated to determine whether an actual pinch or bridge defect will be generated at those locations. If defect generation is likely (based on the lithographical simulation) at a particular location, the corresponding portion of the mask layout can be redesigned to avoid defect generation during actual production. In this method, accurate layout verification can be performed with a minimum of time-consuming lithography modeling.

Abstract: A system that verifies a simulated wafer image against an intended design. During operation, the system receives a design. Next, the system generates a skeleton from the design, wherein the skeleton specifies cell placements and associated bounding boxes for the cell placements, but does not include geometries for the cell placements. The system then computes environments for cell placements based on the skeleton. Next, the system generates templates for cell placements, wherein a template for a cell placement specifies the cell placement and the environment surrounding the cell placement. The system then generates the simulated wafer image by performing model-based simulations for cell placements associated with unique templates.

Abstract: A method for performing layout verification involves identifying feature centerlines in a mask layout, and then performing lithography simulation along the centerlines to generate a set of intensity distributions. At each local maxima or minima in the intensity distributions, further lithography simulation can be performed to determine an exposure pattern width at those local maxima/minima (check positions). The exposure pattern widths can then be evaluated to determine whether an actual pinch or bridge defect will be generated at those locations. If defect generation is likely (based on the lithographical simulation) at a particular location, the corresponding portion of the mask layout can be redesigned to avoid defect generation during actual production. In this method, accurate layout verification can be performed with a minimum of time-consuming lithography modeling.