| Patent application number | Description | Published |
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| 20080301620 | SYSTEM AND METHOD FOR MODEL-BASED SUB-RESOLUTION ASSIST FEATURE GENERATION - Methods are disclosed to create efficient model-based Sub-Resolution Assist Features (MB-SRAF). An SRAF guidance map is created, where each design target edge location votes for a given field point on whether a single-pixel SRAF placed on this field point would improve or degrade the aerial image over the process window. In one embodiment, the SRAF guidance map is used to determine SRAF placement rules and/or to fine tune already-placed SRAFs. In another embodiment the SRAF guidance map is used directly to place SRAFs in a mask layout. | 12-04-2008 |
| 20090053628 | Method of performing model-based scanner tuning - A model-based tuning method for tuning a first lithography system utilizing a reference lithography system, each of which has tunable parameters for controlling imaging performance. The method includes the steps of defining a test pattern and an imaging model; imaging the test pattern utilizing the reference lithography system and measuring the imaging results; imaging the test pattern utilizing the first lithography system and measuring the imaging results; calibrating the imaging model utilizing the imaging results corresponding to the reference lithography system, where the calibrated imaging model has a first set of parameter values; tuning the calibrated imaging model utilizing the imaging results corresponding to the first lithography system, where the tuned calibrated model has a second set of parameter values; and adjusting the parameters of the first lithography system based on a difference between the first set of parameter values and the second set of parameter values. | 02-26-2009 |
| 20090157360 | Methods and system for lithography process window simulation - A method of efficient simulating imaging performance of a lithographic process utilized to image a target design having a plurality of features. The method includes the steps of determining a function for generating a simulated image, where the function accounts for process variations associated with the lithographic process; and generating the simulated image utilizing the function, where the simulated image represents the imaging result of the target design for the lithographic process. In one given embodiment, the function for simulating the aerial images with focus and dose (exposure) variation is defined as: | 06-18-2009 |
| 20090276751 | METHOD OF PERFORMING MASK-WRITER TUNING AND OPTIMIZATION - A model-based tuning method for tuning a first mask writer unit utilizing a reference mask writer unit, each of which has tunable parameters for controlling mask writing performance. The method includes the steps of defining a test pattern and a mask writing model; generating the test pattern utilizing the reference mask writer unit and measuring the mask writing results; generating the test pattern utilizing the first mask writer unit and measuring the mask writing results; calibrating the mask writing model utilizing the mask writing results corresponding to the reference mask writer unit, where the calibrated mask writing model has a first set of parameter values; tuning the calibrated mask writing model utilizing the mask writing results corresponding to the first mask writer unit, where the tuned calibrated model has a second set of parameter values; and adjusting the parameters of the first mask writer unit based on a difference between the first set of parameter values and the second set of parameter values. | 11-05-2009 |
| 20090296055 | LENS HEATING COMPENSATION SYSTEMS AND METHODS - Methods for calibrating a photolithographic system are disclosed. A cold lens contour for a reticle design and at least one hot lens contour for the reticle design are generated from which a process window is defined. Aberrations induced by a lens manipulator are characterized in a manipulator model and the process window is optimized using the manipulator model. Aberrations are characterized by identifying variations in critical dimensions caused by lens manipulation for a plurality of manipulator settings and by modeling behavior of the manipulator as a relationship between manipulator settings and aberrations. The process window may be optimized by minimizing a cost function for a set of critical locations. | 12-03-2009 |
| 20090300573 | MODEL-BASED PROCESS SIMULATION SYSTEMS AND METHODS - Systems and methods for process simulation are described. The methods may use a reference model identifying sensitivity of a reference scanner to a set of tunable parameters. Chip fabrication from a chip design may be simulated using the reference model, wherein the chip design is expressed as one or more masks. An iterative retuning and simulation process may be used to optimize critical dimension in the simulated chip and to obtain convergence of the simulated chip with an expected chip. Additionally, a designer may be provided with a set of results from which an updated chip design is created. | 12-03-2009 |
| 20100010784 | MODEL-BASED SCANNER TUNING SYSTEMS AND METHODS - Systems and methods for tuning photolithographic processes are described. A model of a target scanner is maintained defining sensitivity of the target scanner with reference to a set of tunable parameters. A differential model represents deviations of the target scanner from the reference. The target scanner may be tuned based on the settings of the reference scanner and the differential model. Performance of a family of related scanners may be characterized relative to the performance of a reference scanner. Differential models may include information such as parametric offsets and other differences that may be used to simulate the difference in imaging behavior. | 01-14-2010 |
| 20100119961 | METHODS AND SYSTEM FOR LITHOGRAPHY CALIBRATION - A method of efficient optical and resist parameters calibration based on simulating imaging performance of a lithographic process utilized to image a target design having a plurality of features. The method includes the steps of determining a function for generating a simulated image, where the function accounts for process variations associated with the lithographic process; and generating the simulated image utilizing the function, where the simulated image represents the imaging result of the target design for the lithographic process. Systems and methods for calibration of lithographic processes whereby a polynomial fit is calculated for a nominal configuration of the optical system and which can be used to estimate critical dimensions for other configurations. | 05-13-2010 |
| 20100122225 | PATTERN SELECTION FOR LITHOGRAPHIC MODEL CALIBRATION - The present invention relates generally to methods and apparatuses for test pattern selection for computational lithography model calibration. According to some aspects, the pattern selection algorithms of the present invention can be applied to any existing pool of candidate test patterns. According to some aspects, the present invention automatically selects those test patterns that are most effective in determining the optimal model parameter values from an existing pool of candidate test patterns, as opposed to designing optimal patterns. According to additional aspects, the selected set of test patterns according to the invention is able to excite all the known physics and chemistry in the model formulation, making sure that the wafer data for the test patterns can drive the model calibration to the optimal parameter values that realize the upper bound of prediction accuracy imposed by the model formulation. | 05-13-2010 |
| 20100141925 | SCANNER MODEL REPRESENTATION WITH TRANSMISSION CROSS COEFFICIENTS - The present invention relates to a method for simulating aspects of a lithographic process. According to certain aspects, the present invention uses transmission cross coefficients to represent the scanner data and models. According to other aspects, the present invention enables sensitive data regarding various scanner subsystems to be hidden from third party view, while providing data and models useful for accurate lithographic simulation. | 06-10-2010 |
| 20100146475 | METHODS AND SYSTEM FOR MODEL-BASED GENERIC MATCHING AND TUNING - The present invention relates to a method for tuning lithography systems so as to allow different lithography systems to image different patterns utilizing a known process that does not require a trial and error process to be performed to optimize the process and lithography system settings for each individual lithography system. According to some aspects, the present invention relates to a method for a generic model-based matching and tuning which works for any pattern. Thus it eliminates the requirements for CD measurements or gauge selection. According to further aspects, the invention is also versatile in that it can be combined with certain conventional techniques to deliver excellent performance for certain important patterns while achieving universal pattern coverage at the same time. | 06-10-2010 |
| 20100151364 | Method for identifying and using process window signature patterns for lithography process control - A method for identifying process window signature patterns in a device area of a mask is disclosed. The signature patterns collectively provide a unique response to changes in a set of process condition parameters to the lithography process. The signature patterns enable monitoring of associated process condition parameters for signs of process drift, analyzing of the process condition parameters to determine which are limiting and affecting the chip yields, analyzing the changes in the process condition parameters to determine the corrections that should be fed back into the lithography process or forwarded to an etch process, identifying specific masks that do not transfer the intended pattern to wafers as intended, and identifying groups of masks that share common characteristics and behave in a similar manner with respect to changes in process condition parameters when transferring the pattern to the wafer. | 06-17-2010 |
| 20100162197 | METHOD AND SYSTEM FOR LITHOGRAPHY PROCESS-WINDOW-MAXIMIXING OPTICAL PROXIMITY CORRECTION - The present invention relates to an efficient OPC method of increasing imaging performance of a lithographic process utilized to image a target design having a plurality of features. The method includes the steps of determining a function for generating a simulated image, where the function accounts for process variations associated with the lithographic process; and optimizing target gray level for each evaluation point in each OPC iteration based on this function. In one given embodiment, the function is approximated as a polynomial function of focus and exposure, R(ε, f)=P | 06-24-2010 |
| 20100162199 | THREE-DIMENSIONAL MASK MODEL FOR PHOTOLITHOGRAPHY SIMULATION - A three-dimensional mask model of the invention provides a more realistic approximation of the three-dimensional effects of a photolithography mask with sub-wavelength features than a thin-mask model. In one embodiment, the three-dimensional mask model includes a set of filtering kernels in the spatial domain that are configured to be convolved with thin-mask transmission functions to produce a near-field image. In another embodiment, the three-dimensional mask model includes a set of correction factors in the frequency domain that are configured to be multiplied by the Fourier transform of thin-mask transmission functions to produce a near-field image. | 06-24-2010 |
| 20100180251 | METHOD FOR PROCESS WINDOW OPTIMIZED OPTICAL PROXIMITY CORRECTION - One embodiment of a method for process window optimized optical proximity correction includes applying optical proximity corrections to a design layout, simulating a lithography process using the post-OPC layout and models of the lithography process at a plurality of process conditions to produce a plurality of simulated resist images. A weighted average error in the critical dimension or other contour metric for each edge segment of each feature in the design layout is determined, wherein the weighted average error is an offset between the contour metric at each process condition and the contour metric at nominal condition averaged over the plurality of process conditions. A retarget value for the contour metric for each edge segment is determined using the weighted average error and applied to the design layout prior to applying further optical proximity corrections. | 07-15-2010 |
| 20100203430 | METHODS FOR PERFORMING MODEL-BASED LITHOGRAPHY GUIDED LAYOUT DESIGN - Methods are disclosed to create efficient model-based Sub-Resolution Assist Features (MB-SRAF). An SRAF guidance map is created, where each design target edge location votes for a given field point on whether a single-pixel SRAF placed on this field point would improve or degrade the aerial image over the process window. In one embodiment, the SRAF guidance map is used to determine SRAF placement rules and/or to fine-tune already-placed SRAFs. The SRAF guidance map can be used directly to place SRAFs in a mask layout. Mask layout data including SRAFs may be generated, wherein the SRAFs are placed according to the SRAF guidance map. The SRAF guidance map can comprise an image in which each pixel value indicates whether the pixel would contribute positively to edge behavior of features in the mask layout if the pixel is included as part of a sub-resolution assist feature. | 08-12-2010 |
| 20100229147 | SYSTEM AND METHOD FOR CREATING A FOCUS-EXPOSURE MODEL OF A LITHOGRAPHY PROCESS - A system and a method for creating a focus-exposure model of a lithography process are disclosed. The system and the method utilize calibration data along multiple dimensions of parameter variations, in particular within an exposure-defocus process window space. The system and the method provide a unified set of model parameter values that result in better accuracy and robustness of simulations at nominal process conditions, as well as the ability to predict lithographic performance at any point continuously throughout a complete process window area without a need for recalibration at different settings. With a smaller number of measurements required than the prior-art multiple-model calibration, the focus-exposure model provides more predictive and more robust model parameter values that can be used at any location in the process window. | 09-09-2010 |
| 20100260427 | DELTA TCC FOR FAST SENSITIVITY MODEL COMPUTATION - A method for determining a difference between a reference image and a further image of a pattern, the method including determining a reference imaging function; determining parameters of a difference function representative of a difference between the reference imaging function and a further imaging function; calculating a difference between the reference image and the further image of the pattern based on the difference function and the determined parameters. | 10-14-2010 |
| 20110083113 | System and Method for Lithography Simulation - There are many inventions described and illustrated herein. In one aspect, the present invention is directed to a technique of, and system for simulating, verifying, inspecting, characterizing, determining and/or evaluating the lithographic designs, techniques and/or systems, and/or individual functions performed thereby or components used therein. In one embodiment, the present invention is a system and method that accelerates lithography simulation, inspection, characterization and/or evaluation of the optical characteristics and/or properties, as well as the effects and/or interactions of lithographic systems and processing techniques. In this regard, in one embodiment, the present invention employs a lithography simulation system architecture, including application-specific hardware accelerators, and a processing technique to accelerate and facilitate verification, characterization and/or inspection of a mask design, for example, RET design, including detailed simulation and characterization of the entire lithography process to verify that the design achieves and/or provides the desired results on final wafer pattern. The system includes: (1) general purpose-type computing device(s) to perform the case-based logic having branches and inter-dependency in the data handling and (2) accelerator subsystems to perform a majority of the computation intensive tasks. | 04-07-2011 |
| 20110116067 | Illumination Optimization - A method of optimizing an illumination pupil shape for a lithographic process | 05-19-2011 |
| 20110224956 | Methods and Systems for Parameter-Sensitive and Orthogonal Gauge Design for Lithography Calibration - Methods according to the present invention provide computationally efficient techniques for designing gauge patterns for calibrating a model for use in a simulation process, and which minimize degeneracy between model parameters, and thus maximize pattern coverage for parameter calibration. More specifically, the present invention relates to methods of designing gauge patterns that achieve complete coverage of parameter variations with minimum number of gauges and corresponding measurements in the calibration of a lithographic process utilized to image a target design having a plurality of features. According to some aspects, a method according to the invention includes transforming the space of model parametric space (based on CD sensitivity or Delta TCCs), then iteratively identifying the direction that is most orthogonal to existing gauges' CD sensitivities in this new space, and determining most sensitive line width/pitch combination with optimal assist feature placement which leads to most sensitive CD changes along that direction in model parametric space. | 09-15-2011 |
| 20110230999 | Fast Freeform Source and Mask Co-Optimization Method - The present invention relates to lithographic apparatuses and processes, and more particularly to tools for optimizing illumination sources and masks for use in lithographic apparatuses and processes. According to certain aspects, the present invention significantly speeds up the convergence of the optimization by allowing direct computation of gradient of the cost function. According to other aspects, the present invention allows for simultaneous optimization of both source and mask, thereby significantly speeding the overall convergence. According to still further aspects, the present invention allows for free-form optimization, without the constraints required by conventional optimization techniques. | 09-22-2011 |
| 20110267597 | Method of Performing Model-Based Scanner Tuning - A model-based tuning method for tuning a first lithography system utilizing a reference lithography system, each of which has tunable parameters for controlling imaging performance. The method includes the steps of defining a test pattern and an imaging model; imaging the test pattern utilizing the reference lithography system and measuring the imaging results; imaging the test pattern utilizing the first lithography system and measuring the imaging results; calibrating the imaging model utilizing the imaging results corresponding to the reference lithography system, where the calibrated imaging model has a first set of parameter values; tuning the calibrated imaging model utilizing the imaging results corresponding to the first lithography system, where the tuned calibrated model has a second set of parameter values; and adjusting the parameters of the first lithography system based on a difference between the first set of parameter values and the second set of parameter values. | 11-03-2011 |
| 20120017183 | System and Method for Creating a Focus-Exposure Model of a Lithography Process - A system and a method for creating a focus-exposure model of a lithography process are disclosed. The system and the method utilize calibration data along multiple dimensions of parameter variations, in particular within an exposure-defocus process window space. The system and the method provide a unified set of model parameter values that result in better accuracy and robustness of simulations at nominal process conditions, as well as the ability to predict lithographic performance at any point continuously throughout a complete process window area without a need for recalibration at different settings. With a smaller number of measurements required than the prior-art multiple-model calibration, the focus-exposure model provides more predictive and more robust model parameter values that can be used at any location in the process window. | 01-19-2012 |
| 20120021343 | Process Window Signature Patterns for Lithography Process Control - A method for identifying process window signature patterns in a device area of a mask is disclosed. The signature patterns collectively provide a unique response to changes in a set of process condition parameters to the lithography process. The signature patterns enable monitoring of associated process condition parameters for signs of process drift, analyzing of the process condition parameters to determine which are limiting and affecting the chip yields, analyzing the changes in the process condition parameters to determine the corrections that should be fed back into the lithography process or forwarded to an etch process, identifying specific masks that do not transfer the intended pattern to wafers as intended, and identifying groups of masks that share common characteristics and behave in a similar manner with respect to changes in process condition parameters when transferring the pattern to the wafer. | 01-26-2012 |
| 20120117521 | Pattern-Dependent Proximity Matching/Tuning Including Light Manipulation By Projection Optics - Described herein are methods for matching the characteristics of a lithographic projection apparatus to a reference lithographic projection apparatus, where the matching includes optimizing projection optics characteristics. The projection optics can be used to shape wavefront in the lithographic projection apparatus. According to the embodiments herein, the methods can be accelerated by using linear fitting algorithm or using Taylor series expansion using partial derivatives of transmission cross coefficients (TCCs). | 05-10-2012 |
| 20120117522 | Optimization of Source, Mask and Projection Optics - Embodiments of the present invention provide methods for optimizing a lithographic projection apparatus including optimizing projection optics therein, and preferably including optimizing a source, a mask, and the projection optics. The projection optics is sometimes broadly referred to as “lens”, and therefore the joint optimization process may be termed source mask lens optimization (SMLO). SMLO is desirable over existing source mask optimization process (SMO), partially because including the projection optics in the optimization can lead to a larger process window by introducing a plurality of adjustable characteristics of the projection optics. The projection optics can be used to shape wavefront in the lithographic projection apparatus, enabling aberration control of the overall imaging process. According to the embodiments herein, the optimization can be accelerated by iteratively using linear fitting algorithm or using Taylor series expansion using partial derivatives of transmission cross coefficients (TCCs). | 05-10-2012 |
| 20120124529 | Pattern-Independent and Hybrid Matching/Tuning Including Light Manipulation by Projection Optics - Described herein are methods for matching the characteristics of a lithographic projection apparatus to a reference lithographic projection apparatus, where the matching includes optimizing illumination source and projection optics characteristics. The projection optics can be used to shape wavefront in the lithographic projection apparatus. According to the embodiments herein, the methods can be accelerated by using linear fitting algorithm or using Taylor series expansion using partial derivatives of transmission cross coefficients (TCCs). | 05-17-2012 |
| 20120216156 | Method of Pattern Selection for Source and Mask Optimization - The present invention relates to a method of selecting a subset of patterns from a design, to a method of performing source and mask optimization, and to a computer program product for performing the method of selecting a subset of patterns from a design. According to certain aspects, the present invention enables coverage of the full design while lowering the computation cost by intelligently selecting a subset of patterns from a design in which the design or a modification of the design is configured to be imaged onto a substrate via a lithographic process. The method of selecting the subset of patterns from a design includes identifying a set of patterns from the design related to the predefined representation of the design. By selecting the subset of patterns according to the method, the selected subset of patterns constitutes a similar predefined representation of the design as the set of patterns. | 08-23-2012 |
| 20120253774 | Methods and Systems for Lithography Process Window Simulation - A method of efficient simulating imaging performance of a lithographic process utilized to image a target design having a plurality of features. The method includes the steps of determining a function for generating a simulated image, where the function accounts for process variations associated with the lithographic process; and generating the simulated image utilizing the function, where the simulated image represents the imaging result of the target design for the lithographic process. | 10-04-2012 |
| 20120254813 | Integration of Lithography Apparatus and Mask Optimization Process with Multiple Patterning Process - The present invention relates to lithographic apparatuses and processes, and more particularly to multiple patterning lithography for printing target patterns beyond the limits of resolution of the lithographic apparatus. A method of splitting a pattern to be imaged onto a substrate via a lithographic process into a plurality of sub-patterns is disclosed, wherein the method comprises a splitting step being configured to be aware of requirements of a co-optimization between at least one of the sub-patterns and an optical setting of the lithography apparatus used for the lithographic process. Device characteristic optimization techniques, including intelligent pattern selection based on diffraction signature analysis, may be integrated into the multiple patterning process flow. | 10-04-2012 |
| 20120269421 | System and Method for Lithography Simulation - In one aspect, the present invention is directed to a technique of, and system for simulating, verifying, inspecting, characterizing, determining and/or evaluating the lithographic designs, techniques and/or systems, and/or individual functions performed thereby or components used therein. In one embodiment, the present invention is a system and method that accelerates lithography simulation, inspection, characterization and/or evaluation of the optical characteristics and/or properties, as well as the effects and/or interactions of lithographic systems and processing techniques. | 10-25-2012 |
| 20120303151 | Computational Process Control - The present invention provides a number of innovations in the area of computational process control (CPC). CPC offers unique diagnostic capability during chip manufacturing cycle by analyzing temporal drift of a lithography apparatus/ process, and provides a solution towards achieving performance stability of the lithography apparatus/process. Embodiments of the present invention enable optimized process windows and higher yields by keeping performance of a lithography apparatus and/or parameters of a lithography process substantially close to a pre-defined baseline condition. This is done by comparing the measured temporal drift to a baseline performance using a lithography process simulation model. Once in manufacturing, CPC optimizes a scanner for specific patterns or reticles by leveraging wafer metrology techniques and feedback loop, and monitors and controls, among other things, overlay and/or CD uniformity (CDU) performance over time to continuously maintain the system close to the baseline condition. | 11-29-2012 |
| 20120327383 | System and Method to Ensure Source and Image Stability - The present invention discloses various system and process embodiments where wafer-metrology and direct measurements of the lithography apparatus characteristics are combined to achieve temporal drift reduction in a lithography apparatus/process using a simulation model. The simulation model may have sub-components. For example, a sub-model may represent a first set of optical conditions, and another sub-model may represent a second set of optical conditions. The first set of optical conditions may be a standard set of illumination conditions, and the second set may be a custom set of illumination conditions. Using the inter-relationship of the sub-models, stability control under custom illumination condition can be achieved faster without wafer metrology. | 12-27-2012 |
| 20130014065 | Methods and Systems for Pattern Design with Tailored Response to Wavefront Aberration - The present invention relates to methods and systems for designing gauge patterns that are extremely sensitive to parameter variation, and thus robust against random and repetitive measurement errors in calibration of a lithographic process utilized to image a target design having a plurality of features. The method may include identifying most sensitive line width/pitch combination with optimal assist feature placement which leads to most sensitive CD (or other lithography response parameter) changes against lithography process parameter variations, such as wavefront aberration parameter variation. The method may also include designing gauges which have more than one test patterns, such that a combined response of the gauge can be tailored to generate a certain response to wavefront-related or other lithographic process parameters. The sensitivity against parameter variation leads to robust performance against random measurement error and/or any other measurement error. | 01-10-2013 |
| 20130041750 | METHOD OF ATTENTION-TARGETING FOR ONLINE ADVERTISEMENT - The various embodiments described in the present disclosure, in at least one aspect, relate to computer-implemented methods of online advertisement. In one embodiment, a method includes determining an attention score for each of a plurality of ad creatives corresponding to a common ad content based on at least a correlation between each ad creative and a user's subconscious interest. The method further includes selecting an ad creative among the plurality of ad creatives based at least in part on the attention scores, and presenting the ad content with the selected ad creative as an ad impression to the user. | 02-14-2013 |
| 20130066716 | SENTIMENT-TARGETING FOR ONLINE ADVERTISEMENT - The various embodiments described in the present disclosure, in at least one aspect, relate to computer-implemented methods of online advertisement. In one embodiment, a method includes, in response to receiving a request for an ad to be provided to a user in an online session, identifying a plurality of ads as candidates for consideration, determining one or more sentiments of a content of the online session, and ranking the plurality of identified ads based at least in part on (i) a correlation between the content of the online session and a content of each identified ad, and (ii) a correlation between the one or more sentiments of the content of the online session and the content of each identified ad. | 03-14-2013 |
| 20130139118 | THREE-DIMENSIONAL MASK MODEL FOR PHOTOLITHOGRAPHYSIMULATION - A three-dimensional mask model of the invention provides a more realistic approximation of the three-dimensional effects of a photolithography mask with sub-wavelength features than a thin-mask model. In one embodiment, the three-dimensional mask model includes a set of filtering kernels in the spatial domain that are configured to be convolved with thin-mask transmission functions to produce a near-field image. In another embodiment, the three-dimensional mask model includes a set of correction factors in the frequency domain that are configured to be multiplied by the Fourier transform of thin-mask transmission functions to produce a near-field image. | 05-30-2013 |
| 20130219348 | METHOD FOR PROCESS WINDOW OPTIMIZED OPTICAL PROXIMITY CORRECTION - One embodiment of a method for process window optimized optical proximity correction includes applying optical proximity corrections to a design layout, simulating a lithography process using the post-OPC layout and models of the lithography process at a plurality of process conditions to produce a plurality of simulated resist images. A weighted average error in the critical dimension or other contour metric for each edge segment of each feature in the design layout is determined, wherein the weighted average error is an offset between the contour metric at each process condition and the contour metric at nominal condition averaged over the plurality of process conditions. A retarget value for the contour metric for each edge segment is determined using the weighted average error and applied to the design layout prior to applying further optical proximity corrections. | 08-22-2013 |
| 20130232457 | METHODS AND SYSTEMS FOR LITHOGRAPHY CALIBRATION - A method of efficient optical and resist parameters calibration based on simulating imaging performance of a lithographic process utilized to image a target design having a plurality of features. The method includes the steps of determining a function for generating a simulated image, where the function accounts for process variations associated with the lithographic process; and generating the simulated image utilizing the function, where the simulated image represents the imaging result of the target design for the lithographic process. Systems and methods for calibration of lithographic processes whereby a polynomial fit is calculated for a nominal configuration of the optical system and which can be used to estimate critical dimensions for other configurations. | 09-05-2013 |
| 20130263064 | METHODS AND SYSTEM FOR MODEL-BASED GENERIC MATCHING AND TUNING - The present invention relates to a method for tuning lithography systems so as to allow different lithography systems to image different patterns utilizing a known process that does not require a trial and error process to be performed to optimize the process and lithography system settings for each individual lithography system. According to some aspects, the present invention relates to a method for a generic model-based matching and tuning which works for any pattern. Thus it eliminates the requirements for CD measurements or gauge selection. According to further aspects, the invention is also versatile in that it can be combined with certain conventional techniques to deliver excellent performance for certain important patterns while achieving universal pattern coverage at the same time. | 10-03-2013 |
| 20130311409 | Web-Based Education System - A web-based education system enables instructors to prepare and present online education courses and enables students to locate and participate in available courses. A machine learning algorithm generates a topic-based representation of courses and generates a topic-based representation of user interests. The web-education system then enables users to find relevant courses using the topic-based representations. Recommended courses are ranked according to factors such as relevance to the user, popularity, and course rating. | 11-21-2013 |
| 20130332894 | SYSTEM AND METHOD FOR LITHOGRAPHY SIMULATION - In one aspect, the present invention is directed to a technique of, and system for simulating, verifying, inspecting, characterizing, determining and/or evaluating the lithographic designs, techniques and/or systems, and/or individual functions performed thereby or components used therein. In one embodiment, the present invention is a system and method that accelerates lithography simulation, inspection, characterization and/or evaluation of the optical characteristics and/or properties, as well as the effects and/or interactions of lithographic systems and processing techniques. | 12-12-2013 |
| 20140005998 | METHODS AND SYSTEMS FOR LITHOGRAPHY PROCESS WINDOW SIMULATION | 01-02-2014 |
| 20140012671 | CONTENT-BASED TARGETED ONLINE ADVERTISEMENT - A method of providing targeted online advertisement includes receiving a request for an ad impression to be provided to a user in a network environment. The request includes a first content and a second content. The method also includes, using a processor, determining a context of the first content and a context of the second content, determining a correlation between the context of the first content and the context of the second content, and identifying a plurality of ads as candidates for consideration. The method further includes, using the processor, ranking the plurality of identified ads, selecting an ad among the plurality of identified ads based at least in part on a result of the ranking, and providing the selected ad as the ad impression to be displayed to the user in response to receiving the request. | 01-09-2014 |
| 20140012672 | CONTENT-BASED BIDDING IN ONLINE ADVERTISING - A method of providing targeted online advertisement includes receiving a request for an ad impression. The request includes a first content and a second content. The method also includes determining information related to (i) a context of the first content, (ii) a context of the second content, and (iii) a correlation between the context of the first content and the context of the second content, and providing the determined information to a bidding service, thereby enabling one or more advertisers to place one or more bids on the ad impression based on the provided information. Each of the one or more bids includes a bid price. The method further includes receiving the one or more bids for the ad impression, selecting one of the one or more received bids based at least in part on the bid prices, and providing an ad impression associated with the selected bid. | 01-09-2014 |
| 20140033145 | PATTERN-DEPENDENT PROXIMITY MATCHING/TUNING INCLUDING LIGHT MANIPULATION BY PROJECTION OPTICS - Described herein are methods for matching the characteristics of a lithographic projection apparatus to a reference lithographic projection apparatus, where the matching includes optimizing projection optics characteristics. The projection optics can be used to shape wavefront in the lithographic projection apparatus. According to the embodiments herein, the methods can be accelerated by using linear fitting algorithm or using Taylor series expansion using partial derivatives of transmission cross coefficients (TCCs). | 01-30-2014 |
| 20140046646 | MODEL-BASED SCANNER TUNING SYSTEMS AND METHODS - Systems and methods for tuning photolithographic processes are described. A model of a target scanner is maintained defining sensitivity of the target scanner with reference to a set of tunable parameters. A differential model represents deviations of the target scanner from the reference. The target scanner may be tuned based on the settings of the reference scanner and the differential model. Performance of a family of related scanners may be characterized relative to the performance of a reference scanner. Differential models may include information such as parametric offsets and other differences that may be used to simulate the difference in imaging behavior. | 02-13-2014 |
| 20140047397 | LENS HEATING COMPENSATION SYSTEMS AND METHODS - Methods for calibrating a photolithographic system are disclosed. A cold lens contour for a reticle design and at least one hot lens contour for the reticle design are generated from which a process window is defined. Aberrations induced by a lens manipulator are characterized in a manipulator model and the process window is optimized using the manipulator model. Aberrations are characterized by identifying variations in critical dimensions caused by lens manipulation for a plurality of manipulator settings and by modeling behavior of the manipulator as a relationship between manipulator settings and aberrations. The process window may be optimized by minimizing a cost function for a set of critical locations. | 02-13-2014 |
| 20140068530 | FAST FREEFORM SOURCE AND MASK CO-OPTIMIZATION METHOD - The present invention relates to lithographic apparatuses and processes, and more particularly to tools for optimizing illumination sources and masks for use in lithographic apparatuses and processes. According to certain aspects, the present invention significantly speeds up the convergence of the optimization by allowing direct computation of gradient of the cost function. According to other aspects, the present invention allows for simultaneous optimization of both source and mask, thereby significantly speeding the overall convergence. According to still further aspects, the present invention allows for free-form optimization, without the constraints required by conventional optimization techniques. | 03-06-2014 |
| 20140195993 | THREE-DIMENSIONAL MASK MODEL FOR PHOTOLITHOGRAPHY SIMULATION - A three-dimensional mask model of the invention provides a more realistic approximation of the three-dimensional effects of a photolithography mask with sub-wavelength features than a thin-mask model. In one embodiment, the three-dimensional mask model includes a set of filtering kernels in the spatial domain that are configured to be convolved with thin-mask transmission functions to produce a near-field image. In another embodiment, the three-dimensional mask model includes a set of correction factors in the frequency domain that are configured to be multiplied by the Fourier transform of thin-mask transmission functions to produce a near-field image. | 07-10-2014 |
| 20140208278 | PATTERN SELECTION FOR LITHOGRAPHIC MODEL CALIBRATION - The present invention relates generally to methods and apparatuses for test pattern selection for computational lithography model calibration. According to some aspects, the pattern selection algorithms of the present invention can be applied to any existing pool of candidate test patterns. According to some aspects, the present invention automatically selects those test patterns that are most effective in determining the optimal model parameter values from an existing pool of candidate test patterns, as opposed to designing optimal patterns. According to additional aspects, the selected set of test patterns according to the invention is able to excite all the known physics and chemistry in the model formulation, making sure that the wafer data for the test patterns can drive the model calibration to the optimal parameter values that realize the upper bound of prediction accuracy imposed by the model formulation. | 07-24-2014 |
| 20140282303 | PATTERN-INDEPENDENT AND HYBRID MATCHING/TUNING INCLUDING LIGHT MANIPULATION BY PROJECTION OPTICS - Described herein are methods for matching the characteristics of a lithographic projection apparatus to a reference lithographic projection apparatus, where the matching includes optimizing illumination source and projection optics characteristics. The projection optics can be used to shape wavefront in the lithographic projection apparatus. According to the embodiments herein, the methods can be accelerated by using linear fitting algorithm or using Taylor series expansion using partial derivatives of transmission cross coefficients (TCCs). | 09-18-2014 |
| 20140317580 | METHODS FOR PERFORMING MODEL-BASED LITHOGRAPHY GUIDED LAYOUT DESIGN - Methods are disclosed to create efficient model-based Sub-Resolution Assist Features (MB-SRAF). An SRAF guidance map is created, where each design target edge location votes for a given field point on whether a single-pixel SRAF placed on this field point would improve or degrade the aerial image over the process window. In one embodiment, the SRAF guidance map is used to determine SRAF placement rules and/or to fine-tune already-placed SRAFs. The SRAF guidance map can be used directly to place SRAFs in a mask layout. Mask layout data including SRAFs may be generated, wherein the SRAFs are placed according to the SRAF guidance map. The SRAF guidance map can comprise an image in which each pixel value indicates whether the pixel would contribute positively to edge behavior of features in the mask layout if the pixel is included as part of a sub-resolution assist feature. | 10-23-2014 |
| 20140351773 | MODEL-BASED PROCESS SIMULATION SYSTEMS AND METHODS - Systems and methods for process simulation are described. The methods may use a reference model identifying sensitivity of a reference scanner to a set of tunable parameters. Chip fabrication from a chip design may be simulated using the reference model, wherein the chip design is expressed as one or more masks. An iterative retuning and simulation process may be used to optimize critical dimension in the simulated chip and to obtain convergence of the simulated chip with an expected chip. Additionally, a designer may be provided with a set of results from which an updated chip design is created. | 11-27-2014 |
| 20140365983 | INTEGRATION OF LITHOGRAPHY APPARATUS AND MASK OPTIMIZATION PROCESS WITH MULTIPLE PATTERNING PROCESS - The present invention relates to lithographic apparatuses and processes, and more particularly to multiple patterning lithography for printing target patterns beyond the limits of resolution of the lithographic apparatus. A method of splitting a pattern to be imaged onto a substrate via a lithographic process into a plurality of sub-patterns is disclosed, wherein the method comprises a splitting step being configured to be aware of requirements of a co-optimization between at least one of the sub-patterns and an optical setting of the lithography apparatus used for the lithographic process. Device characteristic optimization techniques, including intelligent pattern selection based on diffraction signature analysis, may be integrated into the multiple patterning process flow. | 12-11-2014 |
| 20150025668 | COMPUTATIONAL PROCESS CONTROL - The present invention provides a number of innovations in the area of computational process control (CPC). CPC offers unique diagnostic capability during chip manufacturing cycle by analyzing temporal drift of a lithography apparatus/ process, and provides a solution towards achieving performance stability of the lithography apparatus/process. Embodiments of the present invention enable optimized process windows and higher yields by keeping performance of a lithography apparatus and/or parameters of a lithography process substantially close to a pre-defined baseline condition. This is done by comparing the measured temporal drift to a baseline performance using a lithography process simulation model. Once in manufacturing, CPC optimizes a scanner for specific patterns or reticles by leveraging wafer metrology techniques and feedback loop, and monitors and controls, among other things, overlay and/or CD uniformity (CDU) performance over time to continuously maintain the system close to the baseline condition. | 01-22-2015 |
| 20150045935 | MODEL-BASED SCANNER TUNING SYSTEMS AND METHODS - Systems and methods for tuning photolithographic processes are described. A model of a target scanner is maintained defining sensitivity of the target scanner with reference to a set of tunable parameters. A differential model represents deviations of the target scanner from the reference. The target scanner may be tuned based on the settings of the reference scanner and the differential model. Performance of a family of related scanners may be characterized relative to the performance of a reference scanner. Differential models may include information such as parametric offsets and other differences that may be used to simulate the difference in imaging behavior. | 02-12-2015 |
| 20150074619 | METHODS AND SYSTEM FOR MODEL-BASED GENERIC MATCHING AND TUNING - The present invention relates to a method for tuning lithography systems so as to allow different lithography systems to image different patterns utilizing a known process that does not require a trial and error process to be performed to optimize the process and lithography system settings for each individual lithography system. According to some aspects, the present invention relates to a method for a generic model-based matching and tuning which works for any pattern. Thus it eliminates the requirements for CD measurements or gauge selection. According to further aspects, the invention is also versatile in that it can be combined with certain conventional techniques to deliver excellent performance for certain important patterns while achieving universal pattern coverage at the same time. | 03-12-2015 |
| 20150074622 | OPTIMIZATION OF SOURCE, MASK AND PROJECTION OPTICS - Embodiments of the present invention provide methods for optimizing a lithographic projection apparatus including optimizing projection optics therein, and preferably including optimizing a source, a mask, and the projection optics. The projection optics is sometimes broadly referred to as “lens”, and therefore the joint optimization process may be termed source mask lens optimization (SMLO). SMLO is desirable over existing source mask optimization process (SMO), partially because including the projection optics in the optimization can lead to a larger process window by introducing a plurality of adjustable characteristics of the projection optics. The projection optics can be used to shape wavefront in the lithographic projection apparatus, enabling aberration control of the overall imaging process. According to the embodiments herein, the optimization can be accelerated by iteratively using linear fitting algorithm or using Taylor series expansion using partial derivatives of transmission cross coefficients (TCCs). | 03-12-2015 |
