Abstract: A method of generating a mask design having optical proximity correction features disposed therein. The methods includes the steps of obtaining a desired target pattern having features to be imaged on a substrate; determining an interference map based on the target pattern, the interference map defining areas of constructive interference and areas of destructive interference between at least one of the features to be imaged and a field area adjacent the at least one feature; and placing assist features in the mask design based on the areas of constructive interference and the areas of destructive interference.

Abstract: A method of printing a pattern having vertically oriented features and horizontally oriented features on a substrate utilizing dipole illumination, which includes the steps of: identifying background areas contained in the pattern; generating a vertical component mask comprising non-resolvable horizontally oriented features in the background areas; generating a horizontal component mask comprising non-resolvable vertically oriented features in the background areas; illuminating said vertical component mask utilizing an X-pole illumination; and illuminating said horizontal component mask utilizing a Y-pole illumination.

Abstract: Disclosed concepts include a method of optimizing polarization of an illumination of a pattern to be formed in a surface of a substrate. Polarized illumination is optimized by determining an illumination intensity for at least one point on an illuminator for at least two polarization states, determining image log slope for the at least one point on the illuminator for the at least two polarization states, determining a maximum image log slope (ILS) where the ILS is near zero for the at least one point on the illuminator, and selecting an optimal polarization state corresponding to the at least two polarization states that minimizes an ILS for the at least one point on the illuminator. This may be repeated for a plurality of points on the illuminator.

Abstract: A method of generating complementary masks for use in a multiple-exposure lithographic imaging process.

Abstract: A method of generating masks for printing a pattern including a plurality of features having varying critical dimensions. The method includes the steps of: (1) obtaining data representing the pattern; (2) defining a plurality of distinct zones based on the critical dimensions of the plurality of features; (3) categorizing each of the features into one of the plurality of distinct zones; and (4) modifying the mask pattern for each feature categorized into a predefined distinct zone of the plurality of distinct zones.

Abstract: A method of optimizing a process for use with a plurality of lithography systems.

Abstract: Optimization of illumination for a full-chip layer is disclosed. A pitch frequency of the full-chip layer is determined so as to generate a pitch frequency histogram of the full-chip layer. The pitch frequency indicates how often a given pitch occurs in the full-chip layer. The pitch frequency histogram is equated to be the first eigenfunction from the sum of coherent system representation of a transformation cross coefficient. An integral equation for the first eigenfunction of the transformation cross coefficient is solved so as to define the optimal illumination for imaging the full-chip layer.

Abstract: A method of generating a mask is provided that optimizes the placement and shape of optical proximity correction (OPC) features such as scattering bars. According to some aspects, the method includes model-based techniques for determining where to place assist features within the design, thereby eliminating the need for experienced mask designers to perform OPC, and also substantially reducing the time required to determine an acceptable OPC solution. According to further aspects, the method provides an OPC assist feature placement technique that enhances the resulting depth of focus even when imaging features have dimensions on the order of a quarter of the wavelength of the imaging system.

Abstract: A method for decomposing a target pattern containing features to be printed on a wafer into multiple patterns. The method includes the steps of: (a) determining a minimum critical dimension and pitch associated with a process to be utilized to image the multiple patterns; (b) generating an anchoring feature; (c) disposing the anchoring feature adjacent a first feature of the target pattern; (d) growing the anchoring feature a predetermined amount so as to define a first area; (e) assigning any feature within the first area to a first pattern; (f) disposing the anchoring feature adjacent a second feature of the target pattern; (g) growing the anchoring feature the predetermined amount so as to define a second area; and (h) assigning any feature within the second area to a second pattern. Steps (c)-(h) are then repeated until the densely spaced features within the target pattern have been assigned to either the first or second pattern.

Abstract: A method of applying optical proximity correction features to a mask having a plurality of features to be imaged. The method includes the steps of defining a set of process parameters to be utilized to image the mask; defining a set of pitch ranges corresponding to pitches exhibited by the plurality of features to be imaged; determining an interference map for at least one of the pitch ranges; and generating a set of rules for positioning scattering bars adjacent the plurality of features based on the interference map, where the set of rules governs scattering bar placement for features having a pitch which falls within the pitch range utilized to generate the interference map.

Abstract: A method of applying optical proximity correction features to a mask having a target pattern comprising a plurality of features to be imaged. The method includes the steps of defining a set of process parameters to be utilized to image the mask; determining an interference map based on the process parameters and the target pattern; defining an area of influence which represents the area about a given feature in the target pattern in which scattering bars will be utilized in the mask; and disposing a scattering bar in the mask adjacent the given feature in a location indicated by said interference map only within the area of influence of the given feature.

Abstract: Disclosed concepts include a method of optimizing an illumination profile of a pattern to be formed in a surface of a substrate. Illumination is optimized by defining a transmission cross coefficient (“TCC”) function determined in accordance with an illumination pupil and a projection pupil corresponding to an illuminator, representing at least one resolvable feature of a mask to be printed on the substrate by at least one impulse function, and creating an interference map of a predetermined order based on the at least one impulse function and the TCC function, wherein the interference map represents the at least one resolvable feature to be printed on the substrate and areas of destructive interference.

Abstract: A method of generating a mask design having optical proximity correction features disposed therein.

Abstract: A method of generating a mask of use in printing a target pattern on a substrate. The method includes the steps of (a) determining a maximum width of features to be imaged on the substrate utilizing phase-structures formed in the mask; (b) identifying all features contained in the target pattern having a width which is equal to or less than the maximum width; (c) extracting all features having a width which is equal to or less than the maximum width from the target pattern; (d) forming phase-structures in the mask corresponding to all features identified in step (b); and (e) forming opaque structures in the mask for all features remaining in target pattern after performing step (c).

Abstract: A method for optically transferring a lithographic pattern corresponding to an integrated circuit utilizing a high transmission attenuated phase-shift mask onto a semiconductor substrate by use of an optical exposure tool. The method comprising the steps of generating a diffraction pattern corresponding to the lithographic pattern, where the diffraction pattern indicates a plurality of spatial frequency components corresponding to the lithographic pattern; determining which of the spatial frequency components need to be captured by a lens in the optical exposure tool in order to accurately reproduce the lithographic pattern; determining a set of illumination conditions required for the optical exposure tool to capture the spatial frequency components necessary for accurately reproducing the lithographic pattern; and illuminating the high transmission attenuated phase-shift mask with this set of illumination conditions.

Abstract: A method of generating a mask for use in a photolithography process. The method includes the steps of determining a target mask pattern having a plurality of features to be imaged and an illumination system to be utilized to image the mask; identifying a critical pitch within the target pattern and optimizing illumination settings of the illumination system for imaging the critical pitch; identifying a forbidden pitch within the target pattern; and modifying the transmittance of the features having a pitch equal to or substantially equal to the forbidden pitch such that the exposure latitude of the features equal to or substantially equal to the forbidden pitch is increased.

Abstract: Improved calibration of a resist model used in critical dimension (CD) calculation is disclosed. A dose function is obtained based on optical tool to be used form the resist on a wafer. The dose function indicates the amount of energy in a resist. The dose function is convolved with a convolution kernel to obtain a modified dose function. The convolution kernel has variable diffusion lengths in different directions. The convolution kernel may include multiple Gaussian kernels each having variable diffusion lengths in different directions. The modified dose function is converted into a CD value which is compared with a target value. If necessary, the diffusion lengths of the Gaussian kernels are adjusted based on the comparison result.

Abstract: A method of decomposing a target pattern having features to be imaged on a substrate so as to allow said features to be imaged in a multi-exposure process. The method includes the steps of: (a) segmenting a plurality of the features into a plurality of polygons; (b) determining the image log slope (ILS) value for each of the plurality of polygons; (c) determining the polygon having the minimum ILS value, and defining a mask containing the polygon; (d) convolving the mask defined in step (c) with an eigen function of a transmission cross coefficient so as to generate an interference map, where the transmission cross coefficient defines the illumination system to be utilized to image the target pattern; and (e) assigning a phase to the polygon based on the value of the interference map at a location corresponding to the polygon, where the phase defines which exposure in said multi-exposure process the polygon is assigned.

Abstract: A method of forming a mask having optical proximity correction features, which includes the steps of obtaining a target pattern of features to be imaged, expanding the width of the features to be imaged, modifying the mask to include assist features which are placed adjacent the edges of the features to be imaged, where the assist features have a length corresponding to the expanded width of the features to be imaged, and returning the features to be imaged from the expanded width to a width corresponding to the target pattern.

Abstract: A method for generating models for simulating the imaging performance of a plurality of exposure tools. The method includes the steps of: generating a calibrated model for a first exposure tool capable of estimating an image to be produced by the first exposure tool for a given photolithography process, where the calibrated model includes a first set of basis functions; generating a model of a second exposure tool capable of estimating an image to be produced by the second exposure tool for the photolithography process, where the model includes a second set of basis functions; and representing the second set of basis functions as a linear combination of the first set of basis functions so as to generate an equivalent model function corresponding to the second exposure tool, where the equivalent model function produces a simulated image corresponding to the image generated by the second exposure tool for the photolithography process.