Patents by Inventor Vishnu G. Kamat

Vishnu G. Kamat 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: 8032845
    Abstract: Using phase shifting on a mask can advantageously improve printed feature resolution on a wafer, thereby allowing greater feature density on an integrated circuit. Phase shifting can create an intensity imbalance between 0 degree and 180 degree phase shifters on the mask. An improved method of designing an alternating PSM to minimize this intensity imbalance is provided. Sub-resolution features, called “blockers”, can be incorporated in the alternating PSM design. Specifically, blockers can be formed in the 0 degree phase shifters. In this configuration, the intensity associated with the 0 degree phase shifters approximates the intensity associated with the corresponding 180 degree phase shifters. Intensity balancing using blockers retains image contrast, thereby ensuring printed feature quality.
    Type: Grant
    Filed: January 27, 2009
    Date of Patent: October 4, 2011
    Assignee: Synopsys, Inc.
    Inventors: Vishnu G. Kamat, Armen Kroyan
  • Publication number: 20090136857
    Abstract: Using phase shifting on a mask can advantageously improve printed feature resolution on a wafer, thereby allowing greater feature density on an integrated circuit. Phase shifting can create an intensity imbalance between 0 degree and 180 degree phase shifters on the mask. An improved method of designing an alternating PSM to minimize this intensity imbalance is provided. Sub-resolution features, called “blockers”, can be incorporated in the alternating PSM design. Specifically, blockers can be formed in the 0 degree phase shifters. In this configuration, the intensity associated with the 0 degree phase shifters approximates the intensity associated with the corresponding 180 degree phase shifters. Intensity balancing using blockers retains image contrast, thereby ensuring printed feature quality.
    Type: Application
    Filed: January 27, 2009
    Publication date: May 28, 2009
    Applicant: Synopsys, Inc.
    Inventors: Vishnu G. Kamat, Armen Kroyan
  • Patent number: 7503030
    Abstract: Using phase shifting on a mask can advantageously improve printed feature resolution on a wafer, thereby allowing greater feature density on an integrated circuit. Phase shifting can create an intensity imbalance between 0 degree and 180 degree phase shifters on the mask. An improved method of designing an alternating PSM to minimize this intensity imbalance is provided. Sub-resolution features, called “blockers”, can be incorporated in the alternating PSM design. Specifically, blockers can be formed in the 0 degree phase shifters. In this configuration, the intensity associated with the 0 degree phase shifters approximates the intensity associated with the corresponding 180 degree phase shifters. Intensity balancing using blockers retains image contrast, thereby ensuring printed feature quality.
    Type: Grant
    Filed: August 4, 2006
    Date of Patent: March 10, 2009
    Assignee: Synopsys, Inc.
    Inventors: Vishnu G. Kamat, Armen Kroyan
  • Patent number: 7275225
    Abstract: A method of correction for design data includes the steps of sequentially applying a plurality of corrections to a plurality of features based on a plurality of feature tolerances to design data in a predetermined order, and providing corrected design data.
    Type: Grant
    Filed: June 4, 2004
    Date of Patent: September 25, 2007
    Assignee: Invarium, Inc.
    Inventor: Vishnu G. Kamat
  • Patent number: 7111276
    Abstract: Using phase shifting on a mask can advantageously improve printed feature resolution on a wafer, thereby allowing greater feature density on an integrated circuit. Phase shifting can create an intensity imbalance between 0 degree and 180 degree phase shifters on the mask. An improved method of designing an alternating PSM to minimize this intensity imbalance is provided. Sub-resolution features, called “blockers”, can be incorporated in the alternating PSM design. Specifically, blockers can be formed in the 0 degree phase shifters. In this configuration, the intensity associated with the 0 degree phase shifters approximates the intensity associated with the corresponding 180 degree phase shifters. Intensity balancing using blockers retains image contrast, thereby ensuring printed feature quality.
    Type: Grant
    Filed: February 5, 2004
    Date of Patent: September 19, 2006
    Assignee: Synopsys, Inc.
    Inventors: Vishnu G. Kamat, Armen Kroyan
  • Patent number: 6724603
    Abstract: An Electrostatic Discharge (ESD) protection circuit (9) includes a plurality of I/O and power supply pad cells (22, 40) that comprise external pads (31, 41) and circuitry requiring ESD protection. The protection circuit includes an array of shunting devices (36, 46) coupled in parallel between an ESD bus (14) and a VSS bus (18) and distributed among the plurality of pad cells. One or more trigger circuits (50) control the shunting devices. ESD events are coupled from any stressed pad onto two separate buses: the ESD bus which routes the high ESD currents to the positive current electrodes of the multiple shunting devices, and a Boost bus (12) which controls the trigger circuits. During an ESD event, the trigger circuits drive the control electrodes of the shunting devices to a voltage level greater than possible with prior art circuits, thereby reducing the on-resistance of the shunting devices.
    Type: Grant
    Filed: August 9, 2002
    Date of Patent: April 20, 2004
    Assignee: Motorola, Inc.
    Inventors: James W. Miller, Geoffrey B. Hall, Alexander Krasin, Michael Stockinger, Matthew D Akers, Vishnu G. Kamat
  • Publication number: 20040027742
    Abstract: An Electrostatic Discharge (ESD) protection circuit (9) includes a plurality of I/O and power supply pad cells (22, 40) that comprise external pads (31, 41) and circuitry requiring ESD protection. The protection circuit includes an array of shunting devices (36, 46) coupled in parallel between an ESD bus (14) and a VSS bus (18) and distributed among the plurality of pad cells. One or more trigger circuits (50) control the shunting devices. ESD events are coupled from any stressed pad onto two separate buses: the ESD bus which routes the high ESD currents to the positive current electrodes of the multiple shunting devices, and a Boost bus (12) which controls the trigger circuits. During an ESD event, the trigger circuits drive the control electrodes of the shunting devices to a voltage level greater than possible with prior art circuits, thereby reducing the on-resistance of the shunting devices.
    Type: Application
    Filed: August 9, 2002
    Publication date: February 12, 2004
    Inventors: James W. Miller, Geoffrey B. Hall, Alexander Krasin, Michael Stockinger, Matthew D. Akers, Vishnu G. Kamat