Patents by Inventor Nishad Udugampola

Nishad Udugampola 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: 9070735
    Abstract: The invention generally relates to a lateral power semiconductor transistor for example in integrated circuits. In particular the invention relates to Lateral Insulated Gate Bipolar Transistors or other lateral bipolar devices such as PIN diodes. The invention also generally relates to a method of increasing switching speed of a lateral bipolar power semiconductor transistor. There is provided a lateral bipolar power semiconductor transistor comprising a first floating semiconductor region of the first conductivity type located laterally spaced to an anode/drain region and a second floating semiconductor region of the second conductivity type located laterally adjacent the first floating semiconductor region, and a floating electrode placed above and in direct contact to the first and second floating semiconductor regions.
    Type: Grant
    Filed: July 2, 2013
    Date of Patent: June 30, 2015
    Assignee: Cambridge Microelectronics Ltd.
    Inventors: Vasantha Pathirana, Nishad Udugampola, Tanya Trajkovic
  • Publication number: 20150008481
    Abstract: The invention generally relates to a lateral power semiconductor transistor for example in integrated circuits. In particular the invention relates to Lateral Insulated Gate Bipolar Transistors or other lateral bipolar devices such as PIN diodes. The invention also generally relates to a method of increasing switching speed of a lateral bipolar power semiconductor transistor. There is provided a lateral bipolar power semiconductor transistor comprising a first floating semiconductor region of the first conductivity type located laterally spaced to an anode/drain region and a second floating semiconductor region of the second conductivity type located laterally adjacent the first floating semiconductor region, and a floating electrode placed above and in direct contact to the first and second floating semiconductor regions.
    Type: Application
    Filed: July 2, 2013
    Publication date: January 8, 2015
    Inventors: Vasantha PATHIRANA, Nishad UDUGAMPOLA, Tanya TRAJKOVIC
  • Patent number: 8866252
    Abstract: We describe a RESURF semiconductor device having an n-drift region with a p-top layer and in which a MOS (Metal Oxide Semiconductor) channel of the device is formed within the p-top layer.
    Type: Grant
    Filed: September 15, 2011
    Date of Patent: October 21, 2014
    Assignee: Cambridge Semiconductor Limited
    Inventors: Tanya Trajkovic, Florin Udrea, Vasantha Pathirana, Nishad Udugampola
  • Patent number: 8482031
    Abstract: This invention generally relates to lateral insulated gate bipolar transistors (LIGBTs), for example in integrated circuits, methods of increasing switching speed of an LIGBT, a method of suppressing parasitic thyristor latch-up in a bulk silicon LIGBT, and methods of fabricating an LIGBT. In particular, a method of suppressing parasitic thyristor latch-up in a bulk silicon LIGBT comprises selecting a current gain ?v for a vertical transistor of a parasitic thyristor of the LIGBT such that in at least one predetermined mode of operation of the LIGBT ?v<1??p where ?p is a current gain of a parasitic bipolar transistor having a base-emitter junction formed by a Schottky contact between the a semiconductor surface and a metal enriched epoxy die attach.
    Type: Grant
    Filed: December 29, 2009
    Date of Patent: July 9, 2013
    Assignee: Cambridge Semiconductor Limited
    Inventors: Florin Udrea, Vasantha Pathirana, Tanya Trajkovic, Nishad Udugampola
  • Patent number: 8415712
    Abstract: This invention generally relates to LIGBTs, ICs comprising an LIGBT and methods of forming an LIGBT, and more particularly to an LIGBT comprising a substrate region of first conductivity type and peak dopant concentration less than about 1×1017/cm3; a lateral drift region of a second, opposite conductivity type adjacent the substrate region and electrically coupled to said substrate region; a charge injection region of the first conductivity type to inject charge toward said lateral drift region; a gate to control flow of said charge in said lateral drift region; metal enriched adhesive below said substrate region; and an intermediate layer below said substrate region to substantially suppress charge injection into said substrate region from said metal enriched adhesive.
    Type: Grant
    Filed: December 29, 2009
    Date of Patent: April 9, 2013
    Assignee: Cambridge Semiconductor Limited
    Inventors: Florin Udrea, Vasantha Pathirana, Tanya Trajkovic, Nishad Udugampola
  • Publication number: 20130069712
    Abstract: We describe a RESURF semiconductor device having an n-drift region with a p-top layer and in which a MOS (Metal Oxide Semiconductor) channel of the device is formed within the p-top layer.
    Type: Application
    Filed: September 15, 2011
    Publication date: March 21, 2013
    Inventors: Tanya Trajkovic, Florin Udrea, Vasantha Pathirana, Nishad Udugampola
  • Patent number: 8174069
    Abstract: A power semiconductor device has a top surface and an opposed bottom surface below a part of which is a thick portion of semiconductor substrate. At least a portion of a drift region of the device has either no or only a thin portion of semiconductor substrate positioned thereunder. The top surface has a high voltage terminal and a low voltage terminal connected thereto to allow a voltage to be applied laterally across the drift region. At least two MOS (metal-oxide-semiconductor) gates are provided on the top surface. The device has at least one relatively highly doped region at its top surface extending between and in contact with said first and second MOS gates. The device has improved protection against triggering of parasitic transistors or latch-up without the on-state voltage drop or switching speed being compromised.
    Type: Grant
    Filed: August 5, 2008
    Date of Patent: May 8, 2012
    Assignee: Cambridge Semiconductor Limited
    Inventors: Florin Udrea, Vasantha Pathirana, Tanya Trajkovic, Nishad Udugampola
  • Publication number: 20110156096
    Abstract: This invention generally relates to LIGBTs, ICs comprising an LIGBT and methods of forming an LIGBT, and more particularly to an LIGBT comprising a substrate region of first conductivity type and peak dopant concentration less than about 1×1017/cm3; a lateral drift region of a second, opposite conductivity type adjacent the substrate region and electrically coupled to said substrate region; a charge injection region of the first conductivity type to inject charge toward said lateral drift region; a gate to control flow of said charge in said lateral drift region; metal enriched adhesive below said substrate region; and an intermediate layer below said substrate region to substantially suppress charge injection into said substrate region from said metal enriched adhesive.
    Type: Application
    Filed: December 29, 2009
    Publication date: June 30, 2011
    Inventors: Florin Udrea, Vasantha Pathirana, Tanya Trajkovic, Nishad Udugampola
  • Publication number: 20110057230
    Abstract: This invention generally relates to lateral insulated gate bipolar transistors (LIGBTs), for example in integrated circuits, methods of increasing switching speed of an LIGBT, a method of suppressing parasitic thyristor latch-up in a bulk silicon LIGBT, and methods of fabricating an LIGBT. In particular, a method of suppressing parasitic thyristor latch-up in a bulk silicon LIGBT comprises selecting a current gain ?v for a vertical transistor of a parasitic thyristor of the LIGBT such that in at least one predetermined mode of operation of the LIGBT ?v<1??p where ?p is a current gain of a parasitic bipolar transistor having a base-emitter junction formed by a Schottky contact between the a semiconductor surface and a metal enriched epoxy die attach.
    Type: Application
    Filed: December 29, 2009
    Publication date: March 10, 2011
    Inventors: Florin Udrea, Vasantha Pathirana, Tanya Trajkovic, Nishad Udugampola
  • Publication number: 20100032712
    Abstract: A power semiconductor device has a top surface and an opposed bottom surface below a part of which is a thick portion of semiconductor substrate. At least a portion of a drift region of the device has either no or only a thin portion of semiconductor substrate positioned thereunder. The top surface has a high voltage terminal and a low voltage terminal connected thereto to allow a voltage to be applied laterally across the drift region. At least two MOS (metal-oxide-semiconductor) gates are provided on the top surface. The device has at least one relatively highly doped region at its top surface extending between and in contact with said first and second MOS gates. The device has improved protection against triggering of parasitic transistors or latch-up without the on-state voltage drop or switching speed being compromised.
    Type: Application
    Filed: August 5, 2008
    Publication date: February 11, 2010
    Applicant: Cambridge Semiconductor Limited
    Inventors: Florin UDREA, Vasantha PATHIRANA, Tanya TRAJKOVIC, Nishad UDUGAMPOLA
  • Patent number: 7605446
    Abstract: A bipolar high voltage/power semiconductor device has a drift region having adjacent its ends regions of different conductivity types respectively. High and low voltage terminals are provided. A first insulated gate terminal and a second insulated gate terminal are also provided. One or more drive circuits provide appropriate voltages to the first and second insulated gate terminals so as to allow current conduction in a first direction or in a second direction that is opposite the first direction.
    Type: Grant
    Filed: July 14, 2006
    Date of Patent: October 20, 2009
    Assignee: Cambridge Semiconductor Limited
    Inventors: Florin Udrea, Nishad Udugampola, Gehan A. J. Amaratunga
  • Patent number: 7531993
    Abstract: A half bridge circuit has a first switch having at least one control gate and a second switch having at least two control gates. A first driver has an output connected to a control gate of the first switch. A second driver has an output connected to a first control gate of the second switch. The output of the first driver is connected to a second control gate of the second switch by a circuit arrangement such that when the first driver is operated to apply a high, positive voltage to the control gate of the first switch, a positive voltage is applied to the second control gate of the second switch, and such that when the first driver is operated to apply a low, zero or small voltage to the control gate of the first switch, a negative voltage is applied to said second control gate of the second switch.
    Type: Grant
    Filed: August 29, 2007
    Date of Patent: May 12, 2009
    Assignee: Cambridge Semiconductor Limited
    Inventors: Florin Udrea, Nishad Udugampola, Gehan A. J. Amaratunga
  • Publication number: 20090058498
    Abstract: A half bridge circuit has a first switch having at least one control gate and a second switch having at least two control gates. A first driver has an output connected to a control gate of the first switch. A second driver has an output connected to a first control gate of the second switch. The output of the first driver is connected to a second control gate of the second switch by a circuit arrangement such that when the first driver is operated to apply a high, positive voltage to the control gate of the first switch, a positive voltage is applied to the second control gate of the second switch, and such that when the first driver is operated to apply a low, zero or small voltage to the control gate of the first switch, a negative voltage is applied to said second control gate of the second switch.
    Type: Application
    Filed: August 29, 2007
    Publication date: March 5, 2009
    Applicant: Cambridge Semiconductor Limited
    Inventors: Florin UDREA, Nishad Udugampola, Gehan Anil Joseph Amaratunga
  • Publication number: 20080012043
    Abstract: A bipolar high voltage/power semiconductor device has a drift region having adjacent its ends regions of different conductivity types respectively. High and low voltage terminals are provided. A first insulated gate terminal and a second insulated gate terminal are also provided. One or more drive circuits provide appropriate voltages to the first and second insulated gate terminals so as to allow current conduction in a first direction or in a second direction that is opposite the first direction.
    Type: Application
    Filed: July 14, 2006
    Publication date: January 17, 2008
    Applicant: Cambridge Semiconductor Limited
    Inventors: Florin Udrea, Nishad Udugampola, Gehan A.J. Amaratunga