Patents by Inventor Andrew Strachan

Andrew Strachan 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: 10937574
    Abstract: Methods and apparatus providing a vertically constructed, temperature sensing resistor are disclosed. An example apparatus includes a semiconductor substrate including a plurality of resistor unit cells arranged in an array, each resistor unit cell formed within the semiconductor substrate and including a top contact. A conductive layer located over the semiconductor substrate electrically connects to a subset of the top contacts.
    Type: Grant
    Filed: September 20, 2019
    Date of Patent: March 2, 2021
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Gregory Keith Cestra, Andrew Strachan
  • Patent number: 10748818
    Abstract: In various examples, a method and apparatus are provided to achieve dynamic biasing to mitigate electrical stress. Described examples include a device includes a first resistor portion having a first terminal and a second terminal, and a second resistor portion having a third terminal and a fourth terminal. The device also includes a well in a substrate proximate to the first resistor portion and the second resistor portion and an insulating layer between the well and the first resistor portion and the second resistor portion. The device also includes a transistor having a control terminal coupled to the second terminal of the first resistor portion and the third terminal of the second resistor portion, the transistor having a first current-handling terminal coupled to a first voltage and a second current-handling terminal coupled to a current source and to the well.
    Type: Grant
    Filed: December 21, 2018
    Date of Patent: August 18, 2020
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Tathagata Chatterjee, Steven Loveless, James Robert Todd, Andrew Strachan
  • Publication number: 20200203230
    Abstract: In various examples, a method and apparatus are provided to achieve dynamic biasing to mitigate electrical stress. Described examples include a device includes a first resistor portion having a first terminal and a second terminal, and a second resistor portion having a third terminal and a fourth terminal. The device also includes a well in a substrate proximate to the first resistor portion and the second resistor portion and an insulating layer between the well and the first resistor portion and the second resistor portion. The device also includes a transistor having a control terminal coupled to the second terminal of the first resistor portion and the third terminal of the second resistor portion, the transistor having a first current-handling terminal coupled to a first voltage and a second current-handling terminal coupled to a current source and to the well.
    Type: Application
    Filed: December 21, 2018
    Publication date: June 25, 2020
    Inventors: Tathagata Chatterjee, Steven Loveless, James Robert Todd, Andrew Strachan
  • Publication number: 20200013528
    Abstract: Methods and apparatus providing a vertically constructed, temperature sensing resistor are disclosed. An example apparatus includes a semiconductor substrate including a plurality of resistor unit cells arranged in an array, each resistor unit cell formed within the semiconductor substrate and including a top contact. A conductive layer located over the semiconductor substrate electrically connects to a subset of the top contacts.
    Type: Application
    Filed: September 20, 2019
    Publication date: January 9, 2020
    Inventors: Gregory Keith Cestra, Andrew Strachan
  • Patent number: 10431357
    Abstract: Methods and apparatus providing a vertically constructed, temperature sensing resistor are disclosed. An example apparatus includes a semiconductor substrate including a first doped region, a second doped region, and a third doped region between the first and second doped regions, the third doped region including a temperature sensitive semiconductor material; a first contact coupled to the first doped region; a second contact opposite the first contact coupled to the second doped region; and an isolation trench to circumscribe the third doped region.
    Type: Grant
    Filed: November 13, 2017
    Date of Patent: October 1, 2019
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Gregory Keith Cestra, Andrew Strachan
  • Publication number: 20190148041
    Abstract: Methods and apparatus providing a vertically constructed, temperature sensing resistor are disclosed. An example apparatus includes a semiconductor substrate including a first doped region, a second doped region, and a third doped region between the first and second doped regions, the third doped region including a temperature sensitive semiconductor material; a first contact coupled to the first doped region; a second contact opposite the first contact coupled to the second doped region; and an isolation trench to circumscribe the third doped region.
    Type: Application
    Filed: November 13, 2017
    Publication date: May 16, 2019
    Inventors: Gregory Keith Cestra, Andrew Strachan
  • Patent number: 8664076
    Abstract: A method of forming a capacitor structure comprises: forming a doped polysilicon layer on an underlying dielectric layer; forming a dielectric stack on the doped polysilicon layer; forming a contact hole in the dielectric stack to expose a surface region of the doped polysilicon layer; forming a conductive contact plug that fills the contact hole and is in contact with the exposed surface of the doped polysilicon layer; forming a plurality of trenches in the dielectric stack such that each trench exposes a corresponding surface region of the doped polysilicon layer; forming a conductive bottom capacitor plate on exposed surfaces of the of the dielectric stack and on exposed surfaces of the doped polysilicon layer; forming a capacitor dielectric layer on the bottom capacitor plate; and forming a conductive top capacitor plate on the capacitor dielectric layer.
    Type: Grant
    Filed: September 21, 2011
    Date of Patent: March 4, 2014
    Assignee: Texas Instruments Incorporated
    Inventors: Venkat Raghavan, Andrew Strachan
  • Patent number: 8541863
    Abstract: An electrically programmable read only memory (EPROM) BIT cell structure formed on a semiconductor substrate comprises an N-type epitaxial layer formed on the semiconductor substrate, an N-type well region formed in the epitaxial layer, LOCOS field oxide formed at the periphery of the well region to define an active device region in the well region, a field oxide ring formed in the active region and space-apart from the LOCOS field oxide to define an EPROM BIT cell region, and an EPROM BIT cell formed in the EPROM BIT cell region.
    Type: Grant
    Filed: November 29, 2010
    Date of Patent: September 24, 2013
    Assignee: National Semiconductor Corporation
    Inventors: Venkat Raghavan, Andrew Strachan
  • Patent number: 8445353
    Abstract: A method for integrating a metal-insulator-metal (MIM) capacitor and a thin film resistor in an integrated circuit is provided that includes depositing a first metal layer outwardly of a semiconductor wafer substrate. A portion of the first metal layer forms a bottom plate for a MIM capacitor. A second metal layer is deposited outwardly of the first metal layer. A first portion of the second metal layer forms a top plate for the MIM capacitor and a second portion of the second metal layer forms contact pads for a thin film resistor.
    Type: Grant
    Filed: September 29, 2009
    Date of Patent: May 21, 2013
    Assignee: National Semiconductor Corporation
    Inventors: Venkat Raghavan, Sheldon Haynie, Andrew Strachan
  • Publication number: 20130069200
    Abstract: A method of forming a capacitor structure comprises: forming a doped polysilicon layer on an underlying dielectric layer; forming a dielectric stack on the doped polysilicon layer; forming a contact hole in the dielectric stack to expose a surface region of the doped polysilsicon layer; forming a conductive contact plug that fills the contact hole and is in contact with the exposed surface of the doped polysilicon layer; forming a plurality of trenches in the dielectric stack such that each trench exposes a corresponding surface region of the doped polysilicon layer; forming a conductive bottom capacitor plate on exposed surfaces of the of the dielectric stack an don exposed surfaces of the doped polysilicon layer; forming a capacitor dielectric layer on the bottom capacitor plate; and forming a conductive top capacitor plate on the capacitor dielectric layer.
    Type: Application
    Filed: September 21, 2011
    Publication date: March 21, 2013
    Inventors: Venkat Raghavan, Andrew Strachan
  • Publication number: 20120132975
    Abstract: An electrically programmable read only memory (EPROM) BIT cell structure formed on a semiconductor substrate comprises an N-type epitaxial layer formed on the semiconductor substrate, an N-type well region formed in the epitaxial layer, LOCOS field oxide formed at the periphery of the well region to define an active device region in the well region, a field oxide ring formed in the active region and space-apart from the LOCOS field oxide to define an EPROM BIT cell region, and an EPROM BIT cell formed in the EPROM BIT cell region.
    Type: Application
    Filed: November 29, 2010
    Publication date: May 31, 2012
    Inventors: Venkat Raghavan, Andrew Strachan
  • Patent number: 8086979
    Abstract: A PMOS device can be designed and manufactured in accordance with the invention to locate its drain junction breakdown point and maximum impact ionization point to reduce or eliminate drain breakdown voltage walk-in. In some embodiments, the drain junction breakdown point and maximum impact ionization point are located sufficiently far from the gate that the device exhibits no significant drain breakdown voltage walk-in. The device can be a high voltage power transistor having an extended drain region including a P-type lightly doped drain (P-LDD) implant, with drain junction breakdown and maximum impact ionization points appropriately located by controlling the implant dose employed to produce the P-LDD implant.
    Type: Grant
    Filed: June 9, 2009
    Date of Patent: December 27, 2011
    Assignee: National Semiconductor Corp.
    Inventors: Douglas Brisbin, Andrew Strachan
  • Publication number: 20090254872
    Abstract: A PMOS device can be designed and manufactured in accordance with the invention to locate its drain junction breakdown point and maximum impact ionization point to reduce or eliminate drain breakdown voltage walk-in. In some embodiments, the drain junction breakdown point and maximum impact ionization point are located sufficiently far from the gate that the device exhibits no significant drain breakdown voltage walk-in. The device can be a high voltage power transistor having an extended drain region including a P-type lightly doped drain (P-LDD) implant, with drain junction breakdown and maximum impact ionization points appropriately located by controlling the implant dose employed to produce the P-LDD implant.
    Type: Application
    Filed: June 9, 2009
    Publication date: October 8, 2009
    Applicant: NATIONAL SEMICONDUCTOR CORPORATION
    Inventors: Douglas Brisbin, Andrew Strachan
  • Patent number: 7560348
    Abstract: A PMOS device can be designed and manufactured in accordance with the invention to locate its drain junction breakdown point and maximum impact ionization point to reduce or eliminate drain breakdown voltage walk-in. In some embodiments, the drain junction breakdown point and maximum impact ionization point are located sufficiently far from the gate that the device exhibits no significant drain breakdown voltage walk-in. The device can be a high voltage power transistor having an extended drain region including a P-type lightly doped drain (P-LDD) implant, with drain junction breakdown and maximum impact ionization points appropriately located by controlling the implant dose employed to produce the P-LDD implant.
    Type: Grant
    Filed: February 14, 2007
    Date of Patent: July 14, 2009
    Assignee: National Semiconductor Corporation
    Inventors: Douglas Brisbin, Andrew Strachan
  • Patent number: 7510944
    Abstract: In a method of forming MIM capacitor structure, a TiW layer is formed and a capacitor mask is used to define areas of the TiW layer that will be sued in the formation of the MIM capacitor. A capacitor mask is then used to expose surface areas of the TiW layer, followed by deposition of a capacitor dielectric layer. A via mask and etch are then performed to provide a contact via to the bottom plate TiW layer. After the via etch, a Ti/TiN liner stack is deposited. The Ti/TiN multilayer stacked film serves as the capacitor top plate as well as the via contact liner film. Next, Tungsten is deposited to fill the vias and a Tungsten planarization step is performed.
    Type: Grant
    Filed: May 10, 2007
    Date of Patent: March 31, 2009
    Assignee: National Semiconductor Corporation
    Inventors: Venkat Raghavan, Andrew Strachan
  • Patent number: 7425741
    Abstract: A biased conductive plate is provided over an NVM cell structure to overcome data retention charge loss due to the presence of dielectric films that are conductive at higher temperatures. The biased conductive plate is preferably formed from the lowest metal layer in the fabrication process flow, but any biased conductive layer can be used.
    Type: Grant
    Filed: July 21, 2005
    Date of Patent: September 16, 2008
    Assignee: National Semiconductor Corporation
    Inventors: Andrew Strachan, Natalia Lavrovskaya, Saurabh Desai, Roozbeh Parsa, Yuri Mirgorodski
  • Publication number: 20070264768
    Abstract: A PMOS device can be designed and manufactured in accordance with the invention to locate its drain junction breakdown point and maximum impact ionization point to reduce or eliminate drain breakdown voltage walk-in. In some embodiments, the drain junction breakdown point and maximum impact ionization point are located sufficiently far from the gate that the device exhibits no significant drain breakdown voltage walk-in. The device can be a high voltage power transistor having an extended drain region including a P-type lightly doped drain (P-LDD) implant, with drain junction breakdown and maximum impact ionization points appropriately located by controlling the implant dose employed to produce the P-LDD implant.
    Type: Application
    Filed: February 14, 2007
    Publication date: November 15, 2007
    Inventors: Douglas Brisbin, Andrew Strachan
  • Patent number: 7192853
    Abstract: A method is provided for forming a graded junction in a semiconductor material having a first conductivity type. Dopant having a second conductivity type opposite the first conductivity type is introduced into a selected region of the semiconductor material to define a primary dopant region therein. The perimeter of the primary dopant region defines a primary pn junction. While introducing dopant into the selected region of the semiconductor material, dopant is simultaneously introduced into the semiconductor material around the perimeter of the primary dopant region and spaced-apart from the primary pn junction. The dopant in the both the primary dopant region and in the dopant around the perimeter of the primary dopant region is then diffused to provide a graded dopant region.
    Type: Grant
    Filed: September 10, 2003
    Date of Patent: March 20, 2007
    Assignee: National Semiconductor Corporation
    Inventors: Andrew Strachan, Vladislav Vashchenko
  • Patent number: 7180140
    Abstract: A PMOS device can be designed and manufactured in accordance with the invention to locate its drain junction breakdown point and maximum impact ionization point to reduce or eliminate drain breakdown voltage walk-in. In some embodiments, the drain junction breakdown point and maximum impact ionization point are located sufficiently far from the gate that the device exhibits no significant drain breakdown voltage walk-in. The device can be a high voltage power transistor having an extended drain region including a P-type lightly doped drain (P-LDD) implant, with drain junction breakdown and maximum impact ionization points appropriately located by controlling the implant dose employed to produce the P-LDD implant.
    Type: Grant
    Filed: April 16, 2004
    Date of Patent: February 20, 2007
    Assignee: National Semiconductor Corporation
    Inventors: Douglas Brisbin, Andrew Strachan
  • Patent number: 7071513
    Abstract: An economical integration of trench VDMOS devices into a conventional BCD process is provided, with the optimization of key aspects of the device layout for low Rds(on) area. Specifically, trench orientation, array geometry, the number of source cells between drain pickups and drain-source spacing are independently optimized. In one embodiment of the invention, the optimized device utilizes a rectangular cell array with an elongation ratio in the range of 5/3–7/3, with a ratio of 5/3 being preferred, and a cell orientation at 45° with respect to the wafer flat on a 100 wafer.
    Type: Grant
    Filed: October 28, 2004
    Date of Patent: July 4, 2006
    Assignee: National Semiconductor Corporation
    Inventors: Terry Dyer, Andrew Strachan