Abstract: A set of original model candidates are first grouped into pairs of original model candidates. A pair of child model candidates is generated for each of the pairs of original model candidates by performing mutation, crossover, or both on the each of the pairs of original model candidates. From the original model candidates and the child model candidates, a set of new model candidates are derived, which includes pairing, based on a similarity function, each child model candidate with one of the corresponding original model candidates; selecting one or both of the model candidates in each of the parent-child pairs based on the similarity function and an objective function as new model candidates; and performing niche clearing to keep a number of the new model candidates in each of niches from exceeding a maximum number. The grouping, generating and deriving operations are then iterated.

Abstract: A set of original model candidates are first divided into groups of original model candidates. Child model candidates are generated by performing crossover on each of the groups of original model candidates without mutation. From the original model candidates and the child model candidates, a set of new model candidates are derived, which includes: selecting a group of new model candidates from each group of the original model candidates and the corresponding child model candidates, selecting an additional new model candidate if adding the additional new model candidate increases overall diversity, and performing niche clearing to keep a number of the new model candidates in each of niches from exceeding a maximum number. The dividing, generating and deriving operations are then iterated. Model caching may be performed by restricting the crossover to the model term level or above.

Abstract: Aspects of the disclosed techniques relate to techniques for resist simulation in lithography. Local minimal light intensity values are determined for a plurality of sample points in boundary regions of an aerial image of a feature to be printed on a resist coating, wherein each of the local minimal light intensity values represents a minimum light intensity value for an area surrounding one of the plurality of sample points. Based on the local minimal light intensity values, horizontal development bias values for the plurality of sample points are then determined. Finally, resist contour data of the feature are determined based at least on the horizontal development bias values.

Abstract: Aspects of the disclosed techniques relate to techniques for resist simulation in lithography. Local light power values are determined for a plurality of sample points in boundary regions of an aerial image of a feature to be printed on a resist coating, wherein each of the local light power values represents a light power value for an area surrounding one of the plurality of sample points. Based on the local light power values, a vertical shrinkage function is constructed. Resist contour data of the feature are then computed based at least on resist shrinkage effects modeled using the local light power values and the vertical shrinkage function.

Abstract: Aspects of the invention relate to techniques of optical simulation for topographically non-uniform substrates. A layout design is simulated to generate an aerial image based on optical models for different types of substrates and for transition regions, along with models for one or more categories of light signals. The one or more categories of light signals comprise trench side-wall reflection signals, trench radiation signals, and trench corner diffraction signals. The one or more categories of light signals may further comprise gate scattering signals and interconnect scattering signals. The models for the one or more categories of light signals may be calibrated with experimental data.

Abstract: Aspects of the invention relate to techniques of optical simulation for topographically non-uniform substrates. A layout design is simulated to generate an aerial image based on optical models for different types of substrates and for transition regions, along with models for one or more categories of light signals. The one or more categories of light signals comprise trench side-wall reflection signals, trench radiation signals, and trench corner diffraction signals. The one or more categories of light signals may further comprise gate scattering signals and interconnect scattering signals. The models for the one or more categories of light signals may be calibrated with experimental data.

Abstract: A method for determining kernels in a sum of coherent systems (SOCS) approximation is provided. Information for an object to be simulated in a manufacturing process is determined. For example, information based on geometries that are included in a layout or mask is determined. A set of kernels from a transmission cross coefficient (TCC) matrix are also determined. The set of kernels may be weighted by importance values in an order of importance. The kernels may then be re-ordered based on the information for the object. These kernels are then re-ordered in the SOCS series to reflect their order of importance. The SOCS series of kernels is then truncated at the number of kernels desired. Accordingly, by re-ordering the kernels that may be more relevant to the object to include higher weights, when the truncation occurs, the kernels that are most relevant may be included in the SOCS approximation.

Abstract: A method for determining kernels in a sum of coherent systems (SOCS) approximation is provided. Information for an object to be simulated in a manufacturing process is determined. For example, information based on geometries that are included in a layout or mask is determined. A set of kernels from a transmission cross coefficient (TCC) matrix are also determined. The set of kernels may be weighted by importance values in an order of importance. The kernels may then be re-ordered based on the information for the object. These kernels are then re-ordered in the SOCS series to reflect their order of importance. The SOCS series of kernels is then truncated at the number of kernels desired. Accordingly, by re-ordering the kernels that may be more relevant to the object to include higher weights, when the truncation occurs, the kernels that are most relevant may be included in the SOCS approximation.

Abstract: A method for determining kernels in a sum of coherent systems (SOCS) approximation is provided. Information for an object to be simulated in a manufacturing process is determined. For example, information based on geometries that are included in a layout or mask is determined. A set of kernels from a transmission cross coefficient (TCC) matrix are also determined. The set of kernels may be weighted by importance values in an order of importance. The kernels may then be re-ordered based on the information for the object. These kernels are then re-ordered in the SOCS series to reflect their order of importance. The SOCS series of kernels is then truncated at the number of kernels desired. Accordingly, by re-ordering the kernels that may be more relevant to the object to include higher weights, when the truncation occurs, the kernels that are most relevant may be included in the SOCS approximation.

Abstract: A system for estimating image intensity within a window area of a wafer using a SOCS decomposition to determine the horizontal and vertical edge fragments that correspond to objects within the window area. Results of the decomposition are used to access lookup tables that store data related to the contribution of the edge fragment to the image intensity. Each lookup table stores data that are computed under a different illumination and feature fabrication or placement conditions.

Abstract: A system for estimating image intensity within a window area of a wafer using a SOCS decomposition to determine the horizontal and vertical edge fragments that correspond to objects within the window area. Results of the decomposition are used to access lookup tables that store data related to the contribution of the edge fragment to the image intensity. Each lookup table stores data that are computed under a different illumination and feature fabrication or placement conditions.

Abstract: A system for estimating image intensity within a window area of a wafer using a SOCS decomposition to determine the horizontal and vertical edge fragments that correspond to objects within the window area. Results of the decomposition are used to access lookup tables that store data related to the contribution of the edge fragment to the image intensity. Each lookup table stores data that are computed under a different illumination and feature fabrication or placement conditions.

Abstract: A method for modeling an image of a mask under illumination by a source is provided. A source map of the source is determined. For example, the source map may be a k-space diagram of plane waves for the source. The source map is then segmented into a plurality of sectors. The plurality of sectors may be pre-defined or defined by a user. A partial image intensity is then calculated for each of the plurality of sectors using a Hopkins approach. The Hopkins approach may be calculated at a point in each of the sectors, such as the center of the sectors. Then, an image intensity for the source map is determined based on the partial image intensities determined for each of the plurality of sectors. For example, each of the partial image intensities is summed to determine a total image intensity for the source map.

Abstract: A method for determining kernels in a sum of coherent systems (SOCS) approximation is provided. Information for an object to be simulated in a manufacturing process is determined. For example, information based on geometries that are included in a layout or mask is determined. A set of kernels from a transmission cross coefficient (TCC) matrix are also determined. The set of kernels may be weighted by importance values in an order of importance. The kernels may then be re-ordered based on the information for the object. These kernels are then re-ordered in the SOCS series to reflect their order of importance. The SOCS series of kernels is then truncated at the number of kernels desired. Accordingly, by re-ordering the kernels that may be more relevant to the object to include higher weights, when the truncation occurs, the kernels that are most relevant may be included in the SOCS approximation.

Abstract: A system for estimating image intensity within a window area of a wafer using a SOCS decomposition to determine the horizontal and vertical edge fragments that correspond to objects within the window area. Results of the decomposition are used to access lookup tables that store data related to the contribution of the edge fragment to the image intensity. Each lookup table stores data that are computed under a different illumination and feature fabrication or placement conditions.

Abstract: A system for estimating image intensity within a window area of a wafer using a SOCS decomposition to determine the horizontal and vertical edge fragments that correspond to objects within the window area. Results of the decomposition are used to access lookup tables that store data related to the contribution of the edge fragment to the image intensity. Each lookup table stores data that are computed under a different illumination and feature fabrication or placement conditions.

Abstract: A complex two-dimensional layout of a photomask or other three-dimensional object is systematically decomposed into a finite number of elementary two-dimensional objects with the ability to cause one-dimensional changes in light transmission properties. An algorithmic implementation of this can take the form of creation of a look-up table that stores all the scattering information of all two-dimensional objects needed for the synthesis of the electromagnetic scattered field from the original three-dimensional object. The domain is decomposed into edges, where pre-calculated electromagnetic field from the diffraction of isolated edges is recycled in the synthesis of the near diffracted field from arbitrary two-dimensional diffracting geometries. The invention has particular applicability in die-to-database inspection where an actual image of a mask is compared with a synthesized image that takes imaging artifacts of comers, edges and proximity into account.