Patent application number | Description | Published |
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 |
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 |
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 |
20110113390 | SMART SELECTION AND/OR WEIGHTING OF PARAMETERS FOR LITHOGRAPHIC PROCESS SIMULATION - The present invention generally relates to simulating a lithographic process, and more particularly to methods for smart selection and smart weighting when selecting parameters and/or kernels used in aerial image computation. According to one aspect, advantages in simulation throughput and/or accuracy can be achieved by selecting TCC kernels more intelligently, allowing highly accurate aerial images to be simulated using a relatively fewer number of TCC kernels than in the state of the art. In other words, the present invention allows for aerial images to be simulated with the same or better accuracy using much less simulation throughput than required in the prior art, all else being equal. | 05-12-2011 |
20110116067 | Illumination Optimization - A method of optimizing an illumination pupil shape for a lithographic process | 05-19-2011 |
20120005637 | SMART SELECTION AND/OR WEIGHTING OF PARAMETERS FOR LITHOGRAPHIC PROCESS SIMULATION - The present invention generally relates to simulating a lithographic process, and more particularly to methods for smart selection and smart weighting when selecting parameters and/or kernels used in aerial image computation. According to one aspect, advantages in simulation throughput and/or accuracy can be achieved by selecting TCC kernels more intelligently, allowing highly accurate aerial images to be simulated using a relatively fewer number of TCC kernels than in the state of the art. In other words, the present invention allows for aerial images to be simulated with the same or better accuracy using much less simulation throughput than required in the prior art, all else being equal. | 01-05-2012 |