Patents by Inventor James A. Culp
James A. Culp has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20120144356Abstract: A method for implementing systematic, variation-aware integrated circuit extraction includes inputting a set of processing conditions to a plurality of variation models, each model corresponding to a separate systematic, parametric variation associated with semiconductor manufacturing of an integrated circuit layout; generating, for each variation model, a netlist update attributable to the associated variation, wherein the netlist update is an update with respect to an original netlist extracted from the integrated circuit layout; and storing the netlist updates generated for each of the processing conditions.Type: ApplicationFiled: February 13, 2012Publication date: June 7, 2012Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Shayak Banerjee, Dureseti Chidambarrao, James A. Culp, Praveen Elakkumanan, Saibal Mukhopadhyay
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Patent number: 8176444Abstract: A method for implementing systematic, variation-aware integrated circuit extraction includes inputting a set of processing conditions to a plurality of variation models, each model corresponding to a separate systematic, parametric variation associated with semiconductor manufacturing of an integrated circuit layout; generating, for each variation model, a netlist update attributable to the associated variation, wherein the netlist update is an update with respect to an original netlist extracted from the integrated circuit layout; and storing the netlist updates generated for each of the processing conditions.Type: GrantFiled: April 20, 2009Date of Patent: May 8, 2012Assignee: International Business Machines CorporationInventors: Shayak Banerjee, Dureseti Chidambarrao, James A. Culp, Praveen Elakkumanan, Saibal Mukhopadhyay
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METHOD AND SYSTEM FOR COMPARING LITHOGRAPHIC PROCESSING CONDITIONS AND OR DATA PREPARATION PROCESSES
Publication number: 20120107969Abstract: A set of optical rule checker (ORC) markers are identified in a simulated lithographic pattern generated for a set of data preparation parameters and lithographic processing conditions. Each ORC marker identifies a feature in the simulated lithographic pattern that violates rules of the ORC. A centerline is defined in each ORC marker, and a minimum dimension region is generated around each centerline with a minimum width that complies with the rules of the ORC. A failure region is defined around each ORC marker by removing regions that overlap with the ORC marker from the minimum dimension region. The areas of all failure regions are added to define a figure of demerit, which characterizes the simulated lithographic pattern. The figure of demerit can be evaluated for multiple simulated lithographic patterns or iteratively decreased by modifying the set of data preparation parameters and lithographic processing conditions.Type: ApplicationFiled: October 28, 2010Publication date: May 3, 2012Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Stephen E. Fischer, James A. Culp, Robert T. Sayah -
Patent number: 8161422Abstract: A method is provided for modeling lithographic processes in the design of photomasks for the manufacture of semiconductor integrated circuits, and more particularly for simulating intermediate range flare effects. For a region of influence (ROI) from first ROI1 of about 5?/NA to distance ROI2 when the point spread function has a slope that is slowly varying according to a predetermined criterion, then mask shapes at least within the distance range from ROI1 to ROI2 are smoothed prior to computing the SOCS convolutions. The method provides a fast method for simulating intermediate range flare effects with sufficient accuracy.Type: GrantFiled: January 6, 2009Date of Patent: April 17, 2012Assignee: International Business Machines CorporationInventors: Maharaj Mukherjee, James A. Culp, Scott M. Mansfield, Kafai Lai, Alan E. Rosenbluth
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Patent number: 8141027Abstract: A method of automatic calibration of a design for manufacturing (DfM) simulation tool includes providing, as a first input, one or more defined rules for each of one or more semiconductor device levels to be simulated by the tool, and providing, as a second input, a plurality of defined feature size threshold ranges and increments for use in histogram generation of a number of failures with respect to a reference circuit; providing, as a third input, the reference circuit; executing the defined rules for the semiconductor device levels to be simulated, and outputting a fail count for the reference circuit at each defined threshold value, thereby generating histogram data of fail count versus threshold for the reference circuit; and providing, as a fourth input, a defined fail count metric, thereby calibrating the DfM tool for use with respect to a target circuit.Type: GrantFiled: January 5, 2010Date of Patent: March 20, 2012Assignee: International Business Machines CorporationInventors: James A. Culp, Jason D. Hibbeler, Lars W. Liebmann, Tina Wagner
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Publication number: 20120066657Abstract: Disclose are embodiments of an integrated circuit design method based on a combination of manufacturability, test coverage and, optionally, diagnostic coverage. Design-for manufacturability (DFM) modifications to the layout of an integrated circuit can be made in light of test coverage. Alternatively, test coverage of an integrated circuit can be established in light of DFM modifications. Alternatively, an iterative process can be performed, where DFM modifications to the layout of an integrated circuit are made in light of test coverage and then test coverage is altered in light of the DFM modifications. Alternatively, DFM modifications to the layout of an integrated circuit can be made in light of test coverage and also diagnostic coverage. In any case, after making DFM modifications and establishing test coverage, any unmodified and untested nodes (and, optionally, any unmodified and undiagnosable tested nodes) in the integrated circuit can be identified and tagged for subsequent in-line inspection.Type: ApplicationFiled: September 13, 2010Publication date: March 15, 2012Applicant: International Business Machines CorporationInventors: Kerry Bernstein, James A. Culp, Leah M.P. Pastel, Kirk D. Peterson, Norman J. Rohrer
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Publication number: 20110307846Abstract: Impact on parametric performance of physical design choices for transistors is scored for on-current and off-current of the transistors. The impact of the design parameters are incorporated into parameters that measure predicted shift in mean on-current and mean off-current and parameters that measure predicted increase in deviations in the distribution of on-current and the off-current. Statistics may be taken at a cell level, a block level, or a chip level to optimize a chip design in a design phase, or to predict changes in parametric yield during manufacturing or after a depressed parametric yield is observed. Further, parametric yield and current level may be predicted region by region and compared with observed thermal emission to pinpoint any anomaly region in a chip to facilitate detection and correction in any mistakes in chip design.Type: ApplicationFiled: August 24, 2011Publication date: December 15, 2011Applicant: International Business Machines CorporationInventors: James A. Culp, Paul Chang, Dureseti Chidambarrao, Praveen Elakkumanan, Jason Hibbeler, Anda C. Mocuta
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Patent number: 8042070Abstract: Impact on parametric performance of physical design choices for transistors is scored for on-current and off-current of the transistors. The impact of the design parameters are incorporated into parameters that measure predicted shift in mean on-current and mean off-current and parameters that measure predicted increase in deviations in the distribution of on-current and the off-current. Statistics may be taken at a cell level, a block level, or a chip level to optimize a chip design in a design phase, or to predict changes in parametric yield during manufacturing or after a depressed parametric yield is observed. Further, parametric yield and current level may be predicted region by region and compared with observed thermal emission to pinpoint any anomaly region in a chip to facilitate detection and correction in any mistakes in chip design.Type: GrantFiled: October 23, 2007Date of Patent: October 18, 2011Assignee: International Business Machines CorporationInventors: James A. Culp, Paul Chang, Dureseti Chidambarrao, Praveen Elakkumanan, Jason Hibbeler, Anda C. Mocuta
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Publication number: 20110179391Abstract: The present invention provides a method and computer program product for designing an on-wafer target for use by a model-based design tool such as OPC or OPC verification. The on-wafer target is modified by modifying a critical dimension so as to improve or optimize an electrical characteristic, while also ensuring that one or more yield constraints are satisfied. The use of an electrically optimized target can result in cost-effective mask designs that better meet the designers' intent.Type: ApplicationFiled: January 19, 2010Publication date: July 21, 2011Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: James A. Culp, Lars W. Liebmann
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Publication number: 20110166686Abstract: A method of automatic calibration of a design for manufacturing (DfM) simulation tool includes providing, as a first input, one or more defined rules for each of one or more semiconductor device levels to be simulated by the tool, and providing, as a second input, a plurality of defined feature size threshold ranges and increments for use in histogram generation of a number of failures with respect to a reference circuit; providing, as a third input, the reference circuit; executing the defined rules for the semiconductor device levels to be simulated, and outputting a fail count for the reference circuit at each defined threshold value, thereby generating histogram data of fail count versus threshold for the reference circuit; and providing, as a fourth input, a defined fail count metric, thereby calibrating the DfM tool for use with respect to a target circuit.Type: ApplicationFiled: January 5, 2010Publication date: July 7, 2011Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: James A. Culp, Jason D. Hibbeler, Lars W. Liebmann, Tina Wagner
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Patent number: 7975244Abstract: A method is provided for designing a mask that includes the use of a pixel-based simulation of a lithographic process model, in which test structures are designed for determining numerical and discretization errors associated with the pixel grid as opposed to other model inaccuracies. The test structure has a plurality of rows of the same sequence of features, but each row is offset from other rows along an x-direction by a multiple of a minimum step size, such as used in modifying masks during optical proximity correction. The images for each row are simulated with a lithographic model that uses the selected pixel-grid size and the differences between row images are compared. If the differences between rows exceed or violate a predetermined criterion, the pixel grid size may be modified to minimize discretization and/or numerical errors due to the choice of pixel grid size.Type: GrantFiled: January 24, 2008Date of Patent: July 5, 2011Assignee: International Business Machines CorporationInventors: Maharaj Mukherjee, James A. Culp, Alan E. Rosenbluth
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Patent number: 7935638Abstract: Methods and structures for enhancing the homogeneity in a ratio of perimeter to surface area among heterogeneous features in different substrate regions. At least one shape on the substrate includes an added edge effective to reduce a difference in the perimeter-to-surface area ratio between the features in a first substrate region and features in a second substrate region. The improved homogeneity in the perimeter-to-surface area ratio reduces variations in a thickness of a conformal layer deposited across the features in the first and second substrate regions.Type: GrantFiled: September 24, 2009Date of Patent: May 3, 2011Assignee: International Business Machines CorporationInventors: James A. Culp, John J. Ellis-Monaghan, Jeffrey P. Gambino, Kirk D. Peterson, Jed H. Rankin
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Publication number: 20110098838Abstract: Disclosed are a system and a method of correcting systematic, design-based, parametric variations on integrated circuit chips to minimize circuit limited yield loss. Processing information and a map of a chip are stored. The processing information can indicate an impact, on a given device parameter, of changes in a value for a specification associated with a given process step. The map can indicate regional variations in the device parameter (e.g., threshold voltage). Based on the processing information and using the map as a guide, different values for the specification are determined, each to be applied in a different region of the integrated circuit chip during the process step in order to offset the mapped regional parametric variations. A process tool can then be selectively controlled to ensure that during chip manufacturing the process step is performed accordingly and, thereby to ensure that the regional parametric variations are minimized.Type: ApplicationFiled: October 22, 2009Publication date: April 28, 2011Applicant: International Business Machines CorporationInventors: James A. Culp, John J. Ellis-Monaghan, Jeffrey P. Gambino, Kirk D. Peterson, Jed H. Rankin
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Publication number: 20110078641Abstract: Mechanisms are provided for characterizing long range variability in integrated circuit manufacturing. A model derivation component tests one or more density pattern samples, which are a fabricated integrated circuits having predetermined pattern densities and careful placement of current-voltage (I-V) sensors. The model derivation component generates one or more empirical models to establish range of influence of long range variability effects in the density pattern sample. A variability analysis component receives an integrated circuit design and, using the one or more empirical models, analyzes the integrated circuit design to isolate possible long range variability effects in the integrated circuit design.Type: ApplicationFiled: September 29, 2009Publication date: March 31, 2011Applicant: International Business Machines CorporationInventors: James A. Culp, Jerry D. Hayes, Ying Liu, Anthony D. Polson
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Publication number: 20110068436Abstract: Methods and structures for enhancing the homogeneity in a ratio of perimeter to surface area among heterogeneous features in different substrate regions. At least one shape on the substrate includes an added edge effective to reduce a difference in the perimeter-to-surface area ratio between the features in a first substrate region and features in a second substrate region. The improved homogeneity in the perimeter-to-surface area ratio reduces variations in a thickness of a conformal layer deposited across the features in the first and second substrate regions.Type: ApplicationFiled: September 24, 2009Publication date: March 24, 2011Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: James A. Culp, John J. Ellis-Monaghan, Jeffrey P. Gambino, Kirk D. Peterson, Jed H. Rankin
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Patent number: 7900178Abstract: A method of integrated circuit (IC) design, an IC design system and computer program product therefore, e.g., for L3GO designs. Special case cells are cells that represent specialized, process dependent components and are provided as dual representation cells with an internal view and external view. The external view is high level abstract representation that includes access pins, boundary and possible blocking shapes/layers and optionally, parameterizations. Each external view includes cell to cell spacing rules and connecting and blocking/keepout rules for placement and routing. The internal representation or, internal view includes regular shapes forming cell components and defining cell construction details and are ground rule clean by construction or verified by simulation or hardware.Type: GrantFiled: February 28, 2008Date of Patent: March 1, 2011Assignee: International Business Machines CorporationInventors: James A. Culp, Gregory A. Northrop, Ming Yin
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Patent number: 7890906Abstract: Disclosed is a method of laying out individual cells of an integrated circuit design, based at least in part on the known polysilicon perimeter densities of those cells. That is, the method embodiments use the knowledge of polysilicon perimeter density for known cells to drive placement of those cells on a chip (i.e., to drive floor-planning). The method embodiments can be used to achieve approximately uniform across-chip polysilicon perimeter density and, thereby to limit performance parameter variations between functional devices that are attributable to variations in polysilicon perimeter density. Alternatively, the method embodiments can be used to selectively control variations in the average polysilicon perimeter density of different regions of a chip and, thereby to selectively control certain performance parameter variations between functional devices located in those different regions.Type: GrantFiled: May 9, 2008Date of Patent: February 15, 2011Assignee: International Business Machines CorporationInventors: Laura S. Chadwick, James A. Culp, David J. Hathaway, Anthony D. Polson
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Publication number: 20110026806Abstract: An emission map of a circuit to be tested for alterations is obtained by measuring the physical circuit to be tested. An emission map of a reference circuit is obtained by measuring a physical reference circuit or by simulating the emissions expected from the reference circuit. The emission map of the circuit to be tested is compared with the emission map of the reference circuit, to determine presence of alterations in the circuit to be tested, as compared to the reference circuit.Type: ApplicationFiled: July 30, 2009Publication date: February 3, 2011Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Kerry Bernstein, James Culp, David F. Heidel, Dirk Pfeiffer, Anthony D. Polson, Peilin Song, Franco Stellari, Robert L. Wisnieff
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Patent number: 7865864Abstract: An approach that provides electrically driven optical proximity correction is described. In one embodiment, there is a method for performing an electrically driven optical proximity correction. In this embodiment, an integrated circuit mask layout representative of a plurality of layered shapes each defined by features and edges is received. A lithography simulation is run on the mask layout. An electrical characteristic is extracted from the output of the lithography simulation for each layer of the mask layout. A determination as to whether the extracted electrical characteristic is in conformance with a target electrical characteristic is made. Edges of the plurality of layered shapes in the mask layout are adjusted in response to determining that the extracted electrical characteristic for a layer in the mask layout fails to conform with the target electrical characteristic.Type: GrantFiled: February 1, 2008Date of Patent: January 4, 2011Assignee: International Business Machines CorporationInventors: Shayak Banerjee, James A. Culp, Praveen Elakkumanan, Lars W. Liebmann
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Patent number: 7849433Abstract: Disclosed are embodiments of forming an integrated circuit with a desired decoupling capacitance and with the uniform and targeted across-chip polysilicon perimeter density. The method includes laying out functional blocks to form the circuit according to the design and also laying out one or more decoupling capacitor blocks to achieve the desired decoupling capacitance. Then, local polysilicon perimeter densities of the blocks are determined and, as necessary, the decoupling capacitor blocks are reconfigured in order to adjust for differences in the local polysilicon perimeter densities. This reconfiguring is performed in a manner that essentially maintains the desired decoupling capacitance. Due to the across-chip polysilicon perimeter density uniformity, functional devices in different regions of the chip will exhibit limited performance parameter variations (e.g., limited threshold voltage variations).Type: GrantFiled: May 9, 2008Date of Patent: December 7, 2010Assignee: International Business Machines CorporationInventors: Laura S. Chadwick, James A. Culp, David J Hathaway, Anthony D. Polson