Patents by Inventor Sani R. Nassif

Sani R. Nassif 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: 8402398
    Abstract: A mechanism is provided for reducing through process delay variation in metal wires by layout retargeting. The mechanism performs initial retargeting, decomposition, and resolution enhancement techniques. For example, the mechanism may perform optical proximity correction. The mechanism then performs lithographic simulation and optical rules checking. The mechanism provides retargeting rules developed based on coupling lithography simulation and resistance/capacitance (RC) extraction. The mechanism performs RC extraction to capture non-linear dependency of RC on design shape dimensions. If the electrical properties in the lithographic simulation are within predefined specifications, the mechanism accepts the retargeting rules; however, if the electrical properties from RC extraction are outside the predefined specifications, the mechanism modifies the retargeting rules and repeats resolution enhancement techniques.
    Type: Grant
    Filed: June 10, 2011
    Date of Patent: March 19, 2013
    Assignee: International Business Machines Corporation
    Inventors: Kanak B. Agarwal, Shayak Banerjee, Sani R. Nassif
  • Publication number: 20130061185
    Abstract: A mechanism is provided for mask assignment for triple patterning lithography. The mechanism identifies tip-to-tip (TT), tip-to-side (TS), and side-to-side (SS) conflicting parts by design rule dependent projection. The mechanism finds stitch location for TT, TS, and SS conflicts separately. The mechanism colors TT, TS, and SS conflicting parts with mask0/mask1, mask0/mask2, mask1/mask2 coloring cycle with each type colored separately. The mechanism uses existing infrastructure of two-way coloring. As a first objective, the mechanism attempts to minimize conflicts. As a second objective, the mechanism attempts to minimize the number of stitches by assigning the two sides of stitches to the same mask. Once coloring of all conflicting parts is done, the mechanism colors non-conflicting parts to maximize minimum overlap of exposures and to use both colors if two sides are different colors and one color if both sides are the same color.
    Type: Application
    Filed: September 1, 2011
    Publication date: March 7, 2013
    Applicant: International Business Machines Corporation
    Inventors: Rani S. Abou Ghaida, Kanak B. Agarwal, Lars W. Liebmann, Sani R. Nassif
  • Publication number: 20130061183
    Abstract: A mechanism is provided for multiple patterning lithography with conflict removal aware coloring. The mechanism makes multiple patterning coloring aware of the conflict removal overhead. The coloring solution explicitly considers ease of conflict removal as one of the coloring objectives. The mechanism pre-computes how much shapes can move in each direction, The mechanism generates a conflict graph where nodes represent shapes in the layout and edges represent conflicts between shapes. The mechanism assigns weights to edges based on available spatial slack between conflicting features, The mechanism then uses the weights to guide multiple patterning coloring. The mechanism prioritizes conflicting features with higher weights to be assigned different colors.
    Type: Application
    Filed: September 1, 2011
    Publication date: March 7, 2013
    Applicant: International Business Machines Corporation
    Inventors: Rani S. Abou Ghaida, Kanak B. Agarwal, Lars W. Liebmann, Sani R. Nassif
  • Patent number: 8365118
    Abstract: A failure probability for a system having multi-fail regions is computed by generating failure directions in a space whose dimensions are the system parameters under consideration. The failure directions are preferably uniform, forming radial slices. The failure directions may be weighted. The radial slices have fail boundaries defining fail regions comparable to broken shells. The distribution of the system parameters is integrated across the broken shell regions to derive a failure contribution for each failure direction. The failure probability is the sum of products of each failure contribution and its weight. Failure contributions are computed using equivalent expressions dependent on the number of dimensions, which can be used to build lookup tables for normalized fail boundary radii. The entire process can be iteratively repeated with successively increasing failure directions until the failure probability converges.
    Type: Grant
    Filed: June 3, 2009
    Date of Patent: January 29, 2013
    Assignee: International Business Machines Corporation
    Inventors: Rajiv V. Joshi, Rouwaida N. Kanj, Zhuo Li, Sani R. Nassif
  • Publication number: 20130014069
    Abstract: Mechanisms are provided for modeling a plurality of devices of an integrated circuit design as a single statistically equivalent wide device. An integrated circuit design is analyzed to identify a portion of the integrated circuit design having the plurality of devices. For the plurality of devices, a statistical model of a single statistically equivalent wide device is generated which has a statistical distribution of at least one operating characteristic of the single statistically equivalent wide device that captures statistical operating characteristic distributions of individual devices in the plurality of devices. At least one statistical operating characteristic of the single statistically equivalent wide device is a complex non-linear function of the statistical operating characteristics of the individual devices. The integrated circuit design is modeled using the single statistically equivalent wide device.
    Type: Application
    Filed: September 14, 2012
    Publication date: January 10, 2013
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Rajiv V. Joshi, Rouwaida N. Kanj, Sani R. Nassif
  • Patent number: 8347240
    Abstract: A mechanism is provided for converting a set of single-layer design rules into a set of split-layer design rules for double patterning lithography (DPL). The set of single-layer design rules and minimum lithographic resolution pitch constraints for single exposure are identified. The set of single-layer design rules comprise a first plurality of minimum distances that are required by a set of first shapes in a single-layer design. Each of the first plurality of minimum distances in the set of single-layer design rules are modified with regard to the minimum lithographic resolution pitch constraints for single exposure, thereby forming the set of split-layer design rules. The set of split-layer design rules comprise a second plurality of minimum distances that are required by a set of second shapes and a set of third shapes in a split-layer design. The set of split-layer design rules are then coded into a design rule checker.
    Type: Grant
    Filed: October 29, 2010
    Date of Patent: January 1, 2013
    Assignee: International Business Machines Corporation
    Inventors: Kanak B. Agarwal, Lars W. Liebmann, Sani R. Nassif
  • Patent number: 8346528
    Abstract: Mechanisms are provided for modeling a plurality of devices of an integrated circuit design as a single statistically equivalent wide device. An integrated circuit design is analyzed to identify a portion of the integrated circuit design having the plurality of devices. For the plurality of devices, a statistical model of a single statistically equivalent wide device is generated which has a statistical distribution of at least one operating characteristic of the single statistically equivalent wide device that captures statistical operating characteristic distributions of individual devices in the plurality of devices. At least one statistical operating characteristic of the single statistically equivalent wide device is a complex non-linear function of the statistical operating characteristics of the individual devices. The integrated circuit design is modeled using the single statistically equivalent wide device.
    Type: Grant
    Filed: September 1, 2009
    Date of Patent: January 1, 2013
    Assignee: International Business Machines Corporation
    Inventors: Rajiv V. Joshi, Rouwaida N. Kanj, Sani R. Nassif
  • Publication number: 20120319674
    Abstract: Calibration of a non-contact current sensor provides improved accuracy for measuring current conducted through a conductor such as an AC branch circuit wire. In a calibration mode, a predetermined current is injected through a voltage sensing conductor integrated in the non-contact current sensor. The magnitude of the magnetic field is measured using a sensing element of the non-contact current sensor. Then, when operating in measurement mode, a current conducted in a wire passing through the non-contact current sensor is determined by correcting the output of the non-contact current sensor using the result of the measurement made in the calibration mode. The voltage sensing conductor is used to provide an indication of the magnitude and/or the phase of the electrostatic potential on the wire. The calibration current may be a DC current, and calibration may be performed while the conductor is carrying an AC current.
    Type: Application
    Filed: June 14, 2011
    Publication date: December 20, 2012
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Wael El-Essawy, Alexandre Peixoto Ferreira, Thomas Walter Keller, Sani R. Nassif
  • Publication number: 20120319675
    Abstract: Calibration of a non-contact voltage sensor provides improved accuracy for measuring voltage on a conductor such as an AC branch circuit wire. In a calibration mode, a predetermined voltage is imposed on a first voltage sensing conductor integrated in the non-contact voltage sensor, while a voltage on a second voltage sensing conductor is measured using a circuit of predetermined input impedance. The capacitance between the wire and each of the voltage sensing conductors may be the same, so that in measurement mode, when the first and second voltage sensing conductors are coupled together, the effective series capacitance provided in combination with the predetermined input impedance is four times as great. The results of the voltage measurement made in the calibration mode can thereby be used to adjust subsequent voltage measurements made in measurement mode with the first and second voltage sensing conductors combined in parallel.
    Type: Application
    Filed: June 14, 2011
    Publication date: December 20, 2012
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Wael El-Essawy, Alexandre Peixoto Ferreira, Thomas Walter Keller, Sani R. Nassif
  • Publication number: 20120317523
    Abstract: A mechanism is provided for reducing through process delay variation in metal wires by layout retargeting. The mechanism performs initial retargeting, decomposition, and resolution enhancement techniques. For example, the mechanism may perform optical proximity correction. The mechanism then performs lithographic simulation and optical rules checking. The mechanism provides retargeting rules developed based on coupling lithography simulation and resistance/capacitance (RC) extraction. The mechanism performs RC extraction to capture non-linear dependency of RC on design shape dimensions. If the electrical properties in the lithographic simulation are within predefined specifications, the mechanism accepts the retargeting rules; however, if the electrical properties from RC extraction are outside the predefined specifications, the mechanism modifies the retargeting rules and repeats resolution enhancement techniques.
    Type: Application
    Filed: June 10, 2011
    Publication date: December 13, 2012
    Applicant: International Business Machines Corporation
    Inventors: Kanak B. Agarwal, Shayak Banerjee, Sani R. Nassif
  • Publication number: 20120317529
    Abstract: A mechanism is provided for rapid estimation of temperature rise in wires due to Joule heating. The mechanism provides fast and accurate estimation of temperature rise in wires due to self heating. Fast estimation is important to handle millions of nets at the full-chip level. The mechanism models lateral heat flow by considering longitudinal heat flow along the wire and lateral thermal coupling to the other wires in the same level. Lateral heat flow can have a significant effect on the temperature rise. The mechanism also models vertical heat flow to the substrate and the heat sink by considering thermal conductivities of vias and inter-layer dielectric (ILD). The mechanism efficiently solves the thermal system to enable physical design optimizations (e.g., wire sizing, etc.) for fixing electromigration violations.
    Type: Application
    Filed: June 10, 2011
    Publication date: December 13, 2012
    Applicant: International Business Machines Corporation
    Inventors: Kanak B. Agarwal, Sani R. Nassif, Ronald D. Rose, Chenggang Xu
  • Patent number: 8321818
    Abstract: Mechanism are provided for model-based retargeting of photolithographic layouts. An optical proximity correction is performed on a set of target patterns for a predetermined number of iterations until a counter value exceeds a maximum predetermined number of iterations in order to produce a set of optical proximity correction mask shapes. A set of lithographic contours is generated for each of the set of optical proximity correction mask shapes in response to the counter value exceeding the maximum predetermined number of iterations. A normalized image log slope (NILS) extraction is performed on the set of target shapes and use the set of lithographic contours to produce NILS values. The set of target patterns is modified based on the NILS values in response to the NILS values failing to be within a predetermined limit. The steps are repeated until the NILS values are within the predetermined limit.
    Type: Grant
    Filed: June 26, 2009
    Date of Patent: November 27, 2012
    Assignee: International Business Machines Corporation
    Inventors: Kanak B. Agarwal, Shayak Banerjee, Sani R. Nassif
  • Publication number: 20120293197
    Abstract: At least one N-type transistor and at least one P-type transistor separate from the digital circuit are sized to represent the total area of the corresponding type transistors in the digital circuit. The gates of the N-type transistor and P-type transistors are set to voltages according to the corresponding off-state logic levels of the digital circuit. The N-type and P-type transistors form a portion of corresponding current mirror circuits, which can provide outputs to a leakage current monitor and/or a control circuit such as a comparator that determines when leakage current for the N-type or P-type devices has exceeded a threshold. The output of the measurement/control circuit can be used to determine a temperature of and/or control operation of the digital circuit or the system environment of the integrated circuit.
    Type: Application
    Filed: May 31, 2012
    Publication date: November 22, 2012
    Applicant: International Business Machines Corporation
    Inventors: Rajiv V. Joshi, Rouwaida N. Kanj, Jente B. Kuang, Sani R. Nassif
  • Publication number: 20120278769
    Abstract: A mechanism is provided for optimizing a photolithograph mask. A given target pattern is received. An initial fictitious mask is generated from the given target pattern and an initial value of ?2 is selected where the initial value of ?2 is used to determine a light intensity and a wafer image. The light intensity for each pixel in the initial fictitious mask and the wafer image for each pixel in the initial fictitious mask are then determined. A determination is then made as to whether a convergence has been achieved by comparing the wafer image generated from the fictitious mask to the given target pattern. Responsive to a convergence of the wafer image generated from the fictitious mask to the given target pattern, a final mask is generated to use to transfer an image to a wafer.
    Type: Application
    Filed: June 25, 2012
    Publication date: November 1, 2012
    Applicant: International Business Machines Corporation
    Inventors: Ying Liu, Sani R. Nassif, Xiaokang Shi
  • Publication number: 20120266113
    Abstract: A mechanism is provided for optimizing a photolithograph mask. A given target pattern is received. An initial fictitious mask is generated from the given target pattern and an initial value of ?2 is selected where the initial value of ?2 is used to determine a light intensity and a wafer image. The light intensity for each pixel in the initial fictitious mask and the wafer image for each pixel in the initial fictitious mask are then determined. A determination is then made as to whether a convergence has been achieved by comparing the wafer image generated from the fictitious mask to the given target pattern. Responsive to a convergence of the wafer image generated from the fictitious mask to the given target pattern, a final mask is generated to use to transfer an image to a wafer.
    Type: Application
    Filed: June 25, 2012
    Publication date: October 18, 2012
    Applicant: International Business Machines Corporation
    Inventors: Ying Liu, Sani R. Nassif, Xiaokang Shi
  • Publication number: 20120266112
    Abstract: A mechanism is provided for optimizing a photolithograph mask. A given target pattern is received. An initial fictitious mask is generated from the given target pattern and an initial value of ?2 is selected where the initial value of ?2 is used to determine a light intensity and a wafer image. The light intensity for each pixel in the initial fictitious mask and the wafer image for each pixel in the initial fictitious mask are then determined. A determination is then made as to whether a convergence has been achieved by comparing the wafer image generated from the fictitious mask to the given target pattern. Responsive to a convergence of the wafer image generated from the fictitious mask to the given target pattern, a final mask is generated to use to transfer an image to a wafer.
    Type: Application
    Filed: June 25, 2012
    Publication date: October 18, 2012
    Applicant: International Business Machines Corporation
    Inventors: Ying Liu, Sani R. Nassif, Xiaokang Shi
  • Publication number: 20120262187
    Abstract: A method and test circuit provide measurements to accurately characterize threshold voltage changes due to negative bias temperature instability (NBTI) and positive bias temperature instability (PBTI). Both the bias temperature instability recovery profile and/or the bias temperature shifts due to rapid repetitions of stress application can be studied. In order to provide accurate measurements when stresses are applied at intervals on the order of tens of nanoseconds while avoiding unwanted recovery, and/or to achieve recovery profile sampling resolutions in the nanosecond range, multiple delay or ring oscillator frequency measurements are made using a delay line that is formed from delay elements that have delay variation substantially caused only by NBTI or PBTI effects. Devices in the delay elements are stressed, and then the delay line/ring oscillator is operated to measure a threshold voltage change for one or more measurement periods on the order of nanoseconds.
    Type: Application
    Filed: June 15, 2012
    Publication date: October 18, 2012
    Applicant: International Business Machines Corporation
    Inventors: Fadi H. Gebara, Jerry D. Hayes, John P. Keane, Sani R. Nassif, Jeremy D. Schaub
  • Publication number: 20120266114
    Abstract: A mechanism is provided for optimizing a photolithograph mask. A given target pattern is received. An initial fictitious mask is generated from the given target pattern and an initial value of ?2 is selected where the initial value of ?2 is used to determine a light intensity and a wafer image. The light intensity for each pixel in the initial fictitious mask and the wafer image for each pixel in the initial fictitious mask are then determined. A determination is then made as to whether a convergence has been achieved by comparing the wafer image generated from the fictitious mask to the given target pattern. Responsive to a convergence of the wafer image generated from the fictitious mask to the given target pattern, a final mask is generated to use to transfer an image to a wafer.
    Type: Application
    Filed: June 25, 2012
    Publication date: October 18, 2012
    Applicant: International Business Machines Corporation
    Inventors: Ying Liu, Sani R. Nassif, Xiaokang Shi
  • Publication number: 20120266111
    Abstract: A mechanism is provided for optimizing a photolithograph mask. A given target pattern is received. An initial fictitious mask is generated from the given target pattern and an initial value of ?2 is selected where the initial value of ?2 is used to determine a light intensity and a wafer image. The light intensity for each pixel in the initial fictitious mask and the wafer image for each pixel in the initial fictitious mask are then determined. A determination is then made as to whether a convergence has been achieved by comparing the wafer image generated from the fictitious mask to the given target pattern. Responsive to a convergence of the wafer image generated from the fictitious mask to the given target pattern, a final mask is generated to use to transfer an image to a wafer.
    Type: Application
    Filed: June 25, 2012
    Publication date: October 18, 2012
    Applicant: International Business Machines Corporation
    Inventors: Ying Liu, Sani R. Nassif, Xiaokang Shi
  • Publication number: 20120260221
    Abstract: A mechanism is provided for optimizing a photolithograph mask. A given target pattern is received. An initial fictitious mask is generated from the given target pattern and an initial value of ?2 is selected where the initial value of ?2 is used to determine a light intensity and a wafer image. The light intensity for each pixel in the initial fictitious mask and the wafer image for each pixel in the initial fictitious mask are then determined. A determination is then made as to whether a convergence has been achieved by comparing the wafer image generated from the fictitious mask to the given target pattern. Responsive to a convergence of the wafer image generated from the fictitious mask to the given target pattern, a final mask is generated to use to transfer an image to a wafer.
    Type: Application
    Filed: June 25, 2012
    Publication date: October 11, 2012
    Applicant: International Business Machines Corporation
    Inventors: Ying Liu, Sani R. Nassif, Xiaokang Shi