Abstract: Methods and systems for photomask defect dispositioning are provided. One method includes directing energy to a photomask and detecting energy from the photomask. The photomask is configured for use at one or more extreme ultraviolet wavelengths of light. The method also includes detecting defects on the photomask based on the detected energy. In addition, the method includes generating charged particle beam images of the photomask at locations of the detected defects. The method further includes dispositioning the detected defects based on the charged particle beam images generated for the detected defects.

Abstract: Methods and systems for photomask defect dispositioning are provided. One method includes directing energy to a photomask and detecting energy from the photomask. The photornask is configured for use at one or more extreme ultraviolet wavelengths of light. The method also includes detecting defects on the photomask based on the detected energy. In addition, the method includes generating charged particle beam images of the photomask at locations of the detected defects. The method further includes dispositioning the detected defects based on the charged particle beam images generated for the detected defects.

Abstract: During a calculation technique, a modification to a reflective photo-mask is calculated. In particular, using information specifying a defect associated with a location on a top surface of the reflective photo-mask, the modification to the reflective photo-mask is calculated. For example, the calculation may involve an inverse optical calculation in which a difference between a pattern associated with the reflective photo-mask at an image plane in a photo-lithographic process and a reference pattern at the image plane in the photo-lithographic process is used to calculate the modification at an object plane in the photo-lithographic process. Note that the modification includes a material added to the top surface of the reflective photo-mask using an additive fabrication process. Moreover, the modification is proximate to the location.

Abstract: A technique for determining a set of surface profiles in a multilayer stack during a fabrication process may be determined using a model of this fabrication process, a geometry of the multilayer stack (such as a pre-defined geometry of the multilayer stack) and a surface profile in the multilayer stack (such as a measured surface profile of the top surface or a bottom surface of the multilayer stack). For example, the model of the fabrication process may be based on a generalized Eikonal equation. In conjunction with deposition rates and/or physical properties of the layers in the multilayer stack, deposition or growth of the multilayer stack may be simulated. Based on the determined set of surface profiles, an acceptance condition of the multilayer stack (such as a multilayer stack in a photo-mask for use in extreme ultra-violet photolithography) may be determined and/or a remedial action may be recommended.

Abstract: During a calculation technique, a modification to a reflective photo-mask is calculated. In particular, using information specifying a defect associated with a recessed area on a top surface of the reflective photo-mask, the modification to the reflective photo-mask is calculated. For example, the calculation may involve an inverse optical calculation in which a difference between a pattern associated with the reflective photo-mask at an image plane in a photo-lithographic process and a reference pattern at the image plane in the photo-lithographic process is used to calculate the modification at an object plane in the photo-lithographic process. Note that the modification includes a negative feature in which one or more pairs of layers in a multilayer stack in the reflective photo-mask are removed using a subtractive fabrication process. Moreover, the modification is proximate to the recessed area.

Abstract: During a calculation technique, a modification to a reflective photo-mask is calculated. In particular, using information specifying a defect associated with a location on a top surface of the reflective photo-mask, the modification to the reflective photo-mask is calculated. For example, the calculation may involve an inverse optical calculation in which a difference between a pattern associated with the reflective photo-mask at an image plane in a photo-lithographic process and a reference pattern at the image plane in the photo-lithographic process is used to calculate the modification at an object plane in the photo-lithographic process. Note that the modification includes a material added to the top surface of the reflective photo-mask using an additive fabrication process. Moreover, the modification is proximate to the location.

Abstract: During a calculation technique, a modification to a reflective photo-mask is calculated. In particular, using information specifying a defect associated with a location on a top surface of the reflective photo-mask, the modification to the reflective photo-mask is calculated. For example, the calculation may involve an inverse optical calculation in which a difference between a pattern associated with the reflective photo-mask at an image plane in a photo-lithographic process and a reference pattern at the image plane in the photo-lithographic process is used to calculate the modification at an object plane in the photo-lithographic process. Note that the modification includes a material added to the top surface of the reflective photo-mask using an additive fabrication process. Moreover, the modification is proximate to the location.

Abstract: A technique for determining a set of surface profiles in a multilayer stack during a fabrication process may be determined using a model of this fabrication process, a geometry of the multilayer stack (such as a pre-defined geometry of the multilayer stack) and a surface profile in the multilayer stack (such as a measured surface profile of the top surface or a bottom surface of the multilayer stack). For example, the model of the fabrication process may be based on a generalized Eikonal equation. In conjunction with deposition rates and/or physical properties of the layers in the multilayer stack, deposition or growth of the multilayer stack may be simulated. Based on the determined set of surface profiles, an acceptance condition of the multilayer stack (such as a multilayer stack in a photo-mask for use in extreme ultra-violet photolithography) may be determined and/or a remedial action may be recommended.

Abstract: During a calculation technique, a modification to a reflective photo-mask is calculated. In particular, using information specifying a defect associated with a recessed area on a top surface of the reflective photo-mask, the modification to the reflective photo-mask is calculated. For example, the calculation may involve an inverse optical calculation in which a difference between a pattern associated with the reflective photo-mask at an image plane in a photo-lithographic process and a reference pattern at the image plane in the photo-lithographic process is used to calculate the modification at an object plane in the photo-lithographic process. Note that the modification includes a negative feature in which one or more pairs of layers in a multilayer stack in the reflective photo-mask are removed using a subtractive fabrication process. Moreover, the modification is proximate to the recessed area.

Abstract: During a calculation technique, a modification to a reflective photo-mask is calculated. In particular, using information specifying a defect associated with a location on a top surface of the reflective photo-mask, the modification to the reflective photo-mask is calculated. For example, the calculation may involve an inverse optical calculation in which a difference between a pattern associated with the reflective photo-mask at an image plane in a photo-lithographic process and a reference pattern at the image plane in the photo-lithographic process is used to calculate the modification at an object plane in the photo-lithographic process. Note that the modification includes a material added to the top surface of the reflective photo-mask using an additive fabrication process. Moreover, the modification is proximate to the location.

Abstract: In a model-based OPC which makes a suitable mask correction for each mask pattern using an optical image intensity simulator, a mask pattern is divided into subregions and the model of optical image intensity simulation is changed according to the contents of the pattern in each subregion. When the minimum dimensions of the mask pattern are smaller than a specific threshold value set near the exposure wavelength, the region is calculated using a high-accuracy model and the other regions are calculated using a high-speed model.

Abstract: A projection exposure method that projects the shape of a hole onto a wafer by projecting a diffracted light, which is produced by applying light to a mask having a pattern for forming a hole pattern, onto the wafer through a projection optical system for exposure, wherein, in a plane substantially perpendicular to an optical axis, the light applied to the mask has a first intensity distribution in which the intensity is higher in the vicinity of eight apexes of an octagon centered at the optical axis than in other areas, the mask has a plurality of first opening patterns are arranged in a rectangular lattice configuration having sides parallel to diagonals of the octagon passing through the optical axis, and a plurality of second opening patterns are arranged in a face-centered rectangular lattice configuration having sides parallel to diagonals of the octagon passing through the optical axis.

Abstract: A pattern prediction method according to an embodiment includes: predicting a second pattern shape from a first pattern shape by using a conversion function and a conversion difference residual error amount function, wherein; the conversion function makes the connection between the first pattern formed by a first step and the second pattern formed by a second step following the first step based on contour shapes of the first pattern and the second pattern, and the conversion difference residual error amount function makes the connection between a residual error amount between a predicted shape of the second pattern obtained from the conversion function and the second pattern shape obtained by actually using the second step, and factors other than the contour shapes of the first pattern and the second pattern.

Abstract: A lithography simulation method of obtaining a resist image by a simulation using a first function and a second function, the lithography simulation method comprising: determining a mask transmission function from a mask layout, modulating the mask transmission function using the first function to determine a modulated mask transmission function, obtaining an optical image of the mask layout using the modulated mask transmission function, and applying the second function to the optical image to obtain the resist image of the mask layout.

Abstract: A method of creating a simulation model, includes acquiring a CD value of a photoresist pattern actually formed based upon a test pattern, acquiring information about a shape of the photoresist pattern, acquiring an intensity distribution of an optical image based upon the test pattern by performing simulation, acquiring an empirical threshold defined according to a CD value on the intensity distribution, which corresponds to the CD value of the photoresist pattern, acquiring a parameter of the optical image based upon the intensity distribution of the optical image, acquiring a first correlation between the information about the shape of the photoresist pattern and the parameter of the optical image, acquiring a second correlation between the information about the shape of the photoresist pattern and the empirical threshold, and acquiring a third correlation between the parameter of the optical image and the empirical threshold by using first and second correlations.

Abstract: A lithography simulation method which predicts the result that a pattern formed on a mask is transferred onto a sample by use of a simulation based on pattern data of the mask includes subjecting a mask layout containing a pattern whose periodicity is disturbed to the simulation. At this time, a calculation area of pattern data used for the simulation is set to an integral multiple of minimum periodic length of the mask layout.

Abstract: A lithography simulation method includes obtaining a mask transmission function from a mask layout, obtaining an optical image of the mask layout by using the mask transmission function, obtaining a function which is filtered by applying a predetermined function filter to the mask transmission function, and correcting the optical image by using the filtered function.

Abstract: Feature-quantity extraction parameters used by feature-quantity extraction functions for calculating feature quantities used as explanatory variables of a resist model for predicting a resist image are set. The feature-quantity extraction functions, for which the feature-quantity extraction parameters are set, are caused to act on optical images of a pattern of a photomask to calculate feature quantities from the optical images.

Abstract: According to an aspect of the present invention, there is provided a method for evaluating a process model, the method including: acquiring, for each of given patterns, a dimensional difference amount between: a first pattern that is formed by actually applying a process onto a corresponding one of the given patterns; and a second pattern that is calculated by applying a process model modeling the process to the corresponding one of the given patterns; and evaluating the process model based on an evaluation index, the evaluation index being based on the number of the patterns at which the dimensional difference amount is equal to or less than a threshold value.

Abstract: A projection exposure method that projects the shape of a hole onto a wafer by projecting a diffracted light, which is produced by applying light to a mask having a pattern for forming a hole pattern, onto the wafer through a projection optical system for exposure, wherein, in a plane substantially perpendicular to an optical axis, the light applied to the mask has a first intensity distribution in which the intensity is higher in the vicinity of eight apexes of an octagon centered at the optical axis than in other areas, the mask has a plurality of first opening patterns are arranged in a rectangular lattice configuration having sides parallel to diagonals of the octagon passing through the optical axis, and a plurality of second opening patterns are arranged in a face-centered rectangular lattice configuration having sides parallel to diagonals of the octagon passing through the optical axis.