Patents by Inventor Ioana Graur

Ioana Graur 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).

  • Patent number: 9904757
    Abstract: A processor receives an integrated circuit design, divides the integrated circuit design into a test portion and a remaining portion, and adds sub-resolution assist features (SRAFs) having different size and spacing parameters to the test portion of the integrated circuit design to generate a single test pattern. Exposure and development equipment performs a single exposure and development process of the single test pattern to produce a single test photoresist. The processor analyzes the single test photoresist to determine which of the size and spacing parameters are unacceptable and which are acceptable, based on differences between the single test photoresist and a model photoresist that the test portion of the integrated circuit design without the SRAFs would produce. The processor adds SRAFs having the acceptable size and spacing parameters to the remaining portion of the integrated circuit design.
    Type: Grant
    Filed: December 31, 2015
    Date of Patent: February 27, 2018
    Assignee: GLOBALFOUNDRIES INC.
    Inventors: Amr Y. Abdo, Ioana Graur
  • Publication number: 20170193150
    Abstract: A processor receives an integrated circuit design, divides the integrated circuit design into a test portion and a remaining portion, and adds sub-resolution assist features (SRAFs) having different size and spacing parameters to the test portion of the integrated circuit design to generate a single test pattern. Exposure and development equipment performs a single exposure and development process of the single test pattern to produce a single test photoresist. The processor analyzes the single test photoresist to determine which of the size and spacing parameters are unacceptable and which are acceptable, based on differences between the single test photoresist and a model photoresist that the test portion of the integrated circuit design without the SRAFs would produce. The processor adds SRAFs having the acceptable size and spacing parameters to the remaining portion of the integrated circuit design.
    Type: Application
    Filed: December 31, 2015
    Publication date: July 6, 2017
    Applicant: GLOBALFOUNDRIES INC.
    Inventors: Amr Y. Abdo, Ioana Graur
  • Patent number: 9330225
    Abstract: Design errors generated employing a mask rule check (MRC) program are indexed and examined one by one by an automated computer program connected to a false error pattern database that contains previously known waivered patterns, a real error pattern database that contains previously known pairs of an error-containing pattern and a corresponding error-free pattern, and optionally a mask house rule database. A waiver is applied to each design error for which a matching pattern is found in the false error pattern database. Each design error for which a match is found in the real error pattern database is modified to substitute an error-free pattern for an error-containing pattern therein. The output of the automated program includes a list of design errors for which no solution is found by the automated program.
    Type: Grant
    Filed: June 5, 2014
    Date of Patent: May 3, 2016
    Assignee: International Business Machines Corporation
    Inventors: Aditya Chaudhary, Kalpesh G. Dave, Mini M. Ghosal, Ioana Graur, Bhavani P. Kumar
  • Publication number: 20150356228
    Abstract: Design errors generated employing a mask rule check (MRC) program are indexed and examined one by one by an automated computer program connected to a false error pattern database that contains previously known waivered patterns, a real error pattern database that contains previously known pairs of an error-containing pattern and a corresponding error-free pattern, and optionally a mask house rule database. A waiver is applied to each design error for which a matching pattern is found in the false error pattern database. Each design error for which a match is found in the real error pattern database is modified to substitute an error-free pattern for an error-containing pattern therein. The output of the automated program includes a list of design errors for which no solution is found by the automated program.
    Type: Application
    Filed: June 5, 2014
    Publication date: December 10, 2015
    Applicant: International Business Machines Corporation
    Inventors: Aditya Chaudhary, Kalpesh G. Dave, Mini M. Ghosal, Ioana Graur, Bhavani P. Kumar
  • Patent number: 9087739
    Abstract: Improved fidelity to an integrated circuit pattern design in a semiconductor structure ultimately produced is achieved by modeling material removal and deposition processes in regard to materials, reactant, feature size, feature density, process parameters and the like as well as the effects of such parameters on etch and material deposition bias due to microloading and RIE lag (including inverse RIE lag) and using the models to work backward through the intended manufacturing method steps, including hard mask pattern decomposition, to morphologically develop feature patterns for use in most or all process steps which will result in the desired feature sizes and shapes at the completion of the overall process. Modeling of processes may be simplified through use of process assist features to locally adjust rates of material deposition and removal.
    Type: Grant
    Filed: October 19, 2009
    Date of Patent: July 21, 2015
    Assignee: International Business Machines Corporation
    Inventors: Derren N. Dunn, Ioana Graur, Scott M. Mansfield
  • Patent number: 9034562
    Abstract: Improved fidelity to an integrated circuit pattern design in a semiconductor structure ultimately produced is achieved by modeling material removal and deposition processes in regard to materials, reactant, feature size, feature density, process parameters and the like as well as the effects of such parameters on etch and material deposition bias due to microloading and RIE lag (including inverse RIE lag) and using the models to work backward through the intended manufacturing method steps, including hard mask pattern decomposition, to morphologically develop feature patterns for use in most or all process steps which will result in the desired feature sizes and shapes at the completion of the overall process. Modeling of processes may be simplified through use of process assist features to locally adjust rates of material deposition and removal.
    Type: Grant
    Filed: January 31, 2013
    Date of Patent: May 19, 2015
    Assignee: International Business Machines Corporation
    Inventors: Derren Neylon Dunn, Ioana Graur, Scott Marshall Mansfield
  • Patent number: 8174681
    Abstract: A method is provided for calibrating a model of a lithographic process that includes defining a parameter space of lithographic model parameters that are expected in an integrated circuit layout. The parameter space is defined according to bin values of a lithographic model parameter that span the range from a predetermined minimum and maximum value of the model parameter. The bin values may be incremented uniformly between the maximum and minimum parameter values, or may be distributed according to a weighting. The lithographic model is calibrated to an initial calibration test pattern. The resulting simulated calibration pattern is evaluated to determine whether the model parameter space is adequately populated. If the parameter space is over or under populated, the calibration pattern is modified until the calibration pattern test values adequately populate the parameter space, so that the final calibrated lithographic process model will more reliably predict images over the full range of image parameters.
    Type: Grant
    Filed: January 6, 2009
    Date of Patent: May 8, 2012
    Assignee: International Business Machines Corporation
    Inventors: Ioana Graur, Geng Han, Scott M. Mansfield, Michael Scaman
  • Patent number: 8166423
    Abstract: Solutions for verifying photomask designs are disclosed.
    Type: Grant
    Filed: September 8, 2009
    Date of Patent: April 24, 2012
    Assignee: International Business Machines Corporation
    Inventors: Scott M. Mansfield, James A. Bruce, Gregory J. Dick, Ioana Graur
  • Patent number: 8108804
    Abstract: Embodiments of the present invention provide a method of performing photo-mask correction. The method includes identifying a hot-spot in a photo-mask that violates one or more predefined rules; creating a window area in the photo-mask that surrounds the hot spot; categorizing the window area; selecting a solution, from a library of pre-computed solutions, based on a category of the window area; and applying the solution to the hot spot. A service-oriented architecture (SOA) system that synchronizes the design to the process is also provided.
    Type: Grant
    Filed: January 19, 2009
    Date of Patent: January 31, 2012
    Assignee: International Business Machines Corporation
    Inventors: Ioana Graur, Scott M. Mansfield
  • Patent number: 8078995
    Abstract: Modeling of lithographic processes for use in the design of photomasks for the manufacture of semiconductor integrated circuits, and particularly to the modeling of the complex effects due to interaction of the illuminating light with the mask topography, is provided. An isofield perturbation to a thin mask representation of the mask is provided by determining, for the components of the illumination, differences between the electric field on a feature edge having finite thickness and on the corresponding feature edge of a thin mask representation. An isofield perturbation is obtained from a weighted coherent combination of the differences for each illumination polarization. The electric field of a mask having topographic edges is represented by combining a thin mask representation with the isofield perturbation applied to each edge of the mask.
    Type: Grant
    Filed: January 6, 2009
    Date of Patent: December 13, 2011
    Assignee: International Business Machines Corporation
    Inventors: Jaione Tirapu Azpiroz, Alan E. Rosenbluth, Ioana Graur
  • Patent number: 8059884
    Abstract: Embodiments of the present invention provide a method of performing printability verification of a mask layout. The method includes creating one or more tight clusters; computing a set of process parameters associated with a point on said mask; comparing said set of process parameters to said one or more tight clusters; and reporting an error when at least one of said process parameters is away from said one or more tight clusters.
    Type: Grant
    Filed: November 8, 2007
    Date of Patent: November 15, 2011
    Assignee: International Business Machines Corporation
    Inventors: Maharaj Mukherjee, Ioana Graur, Alan E. Rosenbluth
  • Publication number: 20110091815
    Abstract: Improved fidelity to an integrated circuit pattern design in a semiconductor structure ultimately produced is achieved by modeling material removal and deposition processes in regard to materials, reactant, feature size, feature density, process parameters and the like as well as the effects of such parameters on etch and material deposition bias due to microloading and RIE lag (including inverse RIE lag) and using the models to work backward through the intended manufacturing method steps, including hard mask pattern decomposition, to morphologically develop feature patterns for use in most or all process steps which will result in the desired feature sizes and shapes at the completion of the overall process. Modeling of processes may be simplified through use of process assist features to locally adjust rates of material deposition and removal.
    Type: Application
    Filed: October 19, 2009
    Publication date: April 21, 2011
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Derren N. Dunn, Ioana Graur, Scott M. Mansfield
  • Publication number: 20110061030
    Abstract: Solutions for verifying photomask designs are disclosed.
    Type: Application
    Filed: September 8, 2009
    Publication date: March 10, 2011
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Scott M. Mansfield, James A. Bruce, Gregory J. Dick, Ioana Graur
  • Patent number: 7860701
    Abstract: A method for predicting functionality of an integrated circuit segment to be lithographically printed on a wafer. Initially there is provided a two-dimensional design of an integrated circuit, including an integrated circuit segment having critical width, and a two-dimensional printed image of the critical width integrated circuit segment is simulated. The method then includes determining a ratio of perimeters or areas of the designed critical width integrated circuit segment to the simulated printed critical width integrated circuit segment, and predicting functionality of the critical width integrated circuit segment after printing based on the ratio of perimeters or areas.
    Type: Grant
    Filed: November 19, 2007
    Date of Patent: December 28, 2010
    Assignee: International Business Machines Corporation
    Inventors: Ioana Graur, Kafai Lai, Rama N. Singh
  • Publication number: 20100185999
    Abstract: Embodiments of the present invention provide a method of performing photo-mask correction. The method includes identifying a hot-spot in a photo-mask that violates one or more predefined rules; creating a window area in the photo-mask that surrounds the hot spot; categorizing the window area; selecting a solution, from a library of pre-computed solutions, based on a category of the window area; and applying the solution to the hot spot. A service-oriented architecture (SOA) system that synchronizes the design to the process is also provided.
    Type: Application
    Filed: January 19, 2009
    Publication date: July 22, 2010
    Applicant: International Business Machines Corporation
    Inventors: Ioana Graur, Scott M. Mansfield
  • Publication number: 20100175042
    Abstract: The present invention relates to the modeling of lithographic processes for use in the design of photomasks for the manufacture of semiconductor integrated circuits, and particularly to the modeling of the complex effects due to interaction of the illuminating light with the mask topography. According to the invention, an isofield perturbation to a thin mask representation of the mask is provided by determining, for the components of the illumination, differences between the electric field on a feature edge having finite thickness and on the corresponding feature edge of a thin mask representation. An isofield perturbation is obtained from a weighted coherent combination of the differences for each illumination polarization. The electric field of a mask having topographic edges is represented by combining a thin mask representation with the isofield perturbation applied to each edge of the mask.
    Type: Application
    Filed: January 6, 2009
    Publication date: July 8, 2010
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Jaione Tirapu Azpiroz, Alan E. Rosenbluth, Ioana Graur
  • Publication number: 20100171031
    Abstract: A method is provided for calibrating a model of a lithographic process that includes defining a parameter space of lithographic model parameters that are expected in an integrated circuit layout. The parameter space is defined according to bin values of a lithographic model parameter that span the range from a predetermined minimum and maximum value of the model parameter. The bin values may be incremented uniformly between the maximum and minimum parameter values, or may be distributed according to a weighting. The lithographic model is calibrated to an initial calibration test pattern. The resulting simulated calibration pattern is evaluated to determine whether the model parameter space is adequately populated. If the parameter space is over or under populated, the calibration pattern is modified until the calibration pattern test values adequately populate the parameter space, so that the final calibrated lithographic process model will more reliably predict images over the full range of image parameters.
    Type: Application
    Filed: January 6, 2009
    Publication date: July 8, 2010
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Ioana Graur, Geng Han, Scott M. Mansfield, Michael Scaman
  • Patent number: 7687207
    Abstract: A method of designing an alternating phase shifting mask for projecting an image of an integrated circuit design. Phase units are binary colorable within each unit of the hierarchical circuit design, e.g., cell, an array, a net, or array of nets and/or cells, the phase shapes. The assignment of phases or colors within a hierarchical unit will be correctly binary colored to satisfy the lithographic, manufacturability and other design rules, referred to collectively as coloring rules. During assembly with other units, the coloring of phases in a hierarchical unit may change (e.g., be reversed or flipped), but the correct binary colorability of a hierarchical unit is preserved, which simplifies assembly of the integrated circuit layout.
    Type: Grant
    Filed: May 15, 2008
    Date of Patent: March 30, 2010
    Assignee: International Business Machines Corporation
    Inventors: Ioana Graur, Young O. Kim, Mark A. Lavin, Lars W. Liebmann
  • Patent number: 7650587
    Abstract: A method for designing a mask for fabricating an integrated circuit is provided wherein a mask layout that requires coloring, such as for alternating phase shift, double-exposure and double-exposure-etch masks, is organized into uncolored hierarchical design units. Prior to modification by OPC, each hierarchical design unit is locally colored. OPC is then performed on the locally colored hierarchical design unit. The local coloring information for the hierarchically arranged OPC-modified design unit may be discarded. After OPC modification, the uncolored OPC-modified design units may be placed within the mask layout, and the flattened data may be colored. Thus, turnaround time for mask design is significantly improved since the numerically intensive OPC is performed on the hierarchical data, avoiding the need to perform OPC on flattened data, whereas the less intensive global coloring is performed on flattened data.
    Type: Grant
    Filed: November 30, 2006
    Date of Patent: January 19, 2010
    Assignee: International Business Machines Corporation
    Inventors: Zachary Baum, Ioana Graur, Lars W. Liebmann, Scott M. Mansfield
  • Patent number: 7624369
    Abstract: A method of designing an integrated circuit is provided in which the design layout is optimized using a process model until the design constraints are satisfied by the image contours simulated by the process model. The process model used in the design phase need not be as accurate as the lithographic model used in preparing the lithographic mask layout during data prep. The resulting image contours are then included with the modified, optimized design layout to the data prep process, in which the mask layout is optimized using the lithographic process model, for example, including RET and OPC. The mask layout optimization matches the images simulated by the lithographic process model with the image contours generated during the design phase, which ensures that the design and manufacturability constraints specified by the designer are satisfied by the optimized mask layout.
    Type: Grant
    Filed: October 31, 2006
    Date of Patent: November 24, 2009
    Assignee: International Business Machines Corporation
    Inventors: Ioana Graur, Geng Han, Scott M. Mansfiled, Lars W. Liebmann