Patents by Inventor Josephine Chang

Josephine Chang 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).

  • Publication number: 20230307533
    Abstract: A field effect transistor, comprising: a substrate and a superlattice of stacked conducting channels on the substrate; a source and a drain spaced-apart from each other on the superlattice; alternating castellations and trenches formed in the superlattice between the source and the drain, wherein the castellations have sidewalls that cut-down through the superlattice to form the trenches and edges of the stacked conducting channels that terminate at the sidewalls; a fringe field dielectric that fills lower volumes of the trenches up to a height on the sidewalls that is higher than first edges of first conducting channels among the stacked conducting channels, such that the fringe field dielectric is adjacent to the first edges; and a gate electrode overlaying the fringe field dielectric and the castellations such that the gate electrode is not adjacent to the first edges.
    Type: Application
    Filed: March 23, 2022
    Publication date: September 28, 2023
    Inventors: Kevin M. Frey, Ken Nagamatsu, Josephine Chang, Robert S. Howell
  • Publication number: 20220093772
    Abstract: A field effect transistor (FET) includes a substrate; a channel material located on the substrate, the channel material comprising one of graphene or a nanostructure; a gate located on a first portion of the channel material; and a contact aligned to the gate, the contact comprising one of a metal silicide, a metal carbide, and a metal, the contact being located over a source region and a drain region of the FET, the source region and the drain region comprising a second portion of the channel material.
    Type: Application
    Filed: December 6, 2021
    Publication date: March 24, 2022
    Inventors: Josephine Chang, Isaac Lauer, Jeffrey Sleight
  • Publication number: 20200411676
    Abstract: An enhancement-mode (e-mode) field effect transistor (FET) comprises a buffer layer, and a superlattice of conducting channels on the buffer layer and including a trench that cuts down through the superlattice into the buffer layer and separates the superlattice into a source-access region and a drain-access region, wherein the buffer layer forms a bottom of the trench. The e-mode FET includes a source and a drain adjacent to the source-access region and the drain-access region, respectively. The e-mode FET further incudes a gate in the trench, such that a voltage above a threshold voltage of the e-mode FET applied to the gate induces a current channel in the buffer layer underneath the gate, which electrically connects the source-access region to the drain-access region to turn on the e-mode FET, and (ii) a voltage below the threshold voltage applied to the gate eliminates the current channel, which electrically disconnects the source-access region from the drain-access region to turn off the e-mode FET.
    Type: Application
    Filed: June 26, 2019
    Publication date: December 31, 2020
    Inventors: Josephine Chang, Ken Nagamatsu, Robert S. Howell, Sarat Saluru
  • Patent number: 10879382
    Abstract: An enhancement-mode (e-mode) field effect transistor (FET) comprises a buffer layer, and a superlattice of conducting channels on the buffer layer and including a trench that cuts down through the superlattice into the buffer layer and separates the superlattice into a source-access region and a drain-access region, wherein the buffer layer forms a bottom of the trench. The e-mode FET includes a source and a drain adjacent to the source-access region and the drain-access region, respectively. The e-mode FET further includes a gate in the trench, such that a voltage above a threshold voltage of the e-mode FET applied to the gate induces a current channel in the buffer layer underneath the gate, which electrically connects the source-access region to the drain-access region to turn on the e-mode FET, and (ii) a voltage below the threshold voltage applied to the gate eliminates the current channel, which electrically disconnects the source-access region from the drain-access region to turn off the e-mode FET.
    Type: Grant
    Filed: June 26, 2019
    Date of Patent: December 29, 2020
    Assignee: NORTHROP GRUMMAN SYSTEMS CORPORATION
    Inventors: Josephine Chang, Ken Nagamatsu, Robert S. Howell, Sarat Saluru
  • Patent number: 10325982
    Abstract: A transistor device comprises a base structure and a superlattice of conducting channels overlying the base structure. The superlattice of conducting channels includes source and drain access regions spaced-apart from each other, a ledge between and spaced-apart from the source and drain access regions, and source-side alternating multichannel ridges and trenches that extend from the source access region to the ledge, each ridge having a topside and opposing sidewalls that each extend from the ledge to the source access region. The transistor device includes gate metal that covers each ridge continuously from the ledge to the source access region, such that the gate metal completely covers the topside of the ridge and edges of the conducting channels that intersect the sidewalls of the ridge.
    Type: Grant
    Filed: May 17, 2018
    Date of Patent: June 18, 2019
    Assignee: NORTHROP GRUMMAN SYSTEMS CORPORATION
    Inventors: Josephine Chang, Ken Alfred Nagamatsu, Robert Samuel Howell, Shalini Gupta
  • Patent number: 9368599
    Abstract: A method for forming a field effect transistor (FET) includes depositing a channel material on a substrate, the channel material comprising one of graphene or a nanostructure; forming a gate over a first portion of the channel material; forming spacers adjacent to the gate; depositing a contact material over the channel material, gate, and spacers; depositing a dielectric material over the contact material; removing a portion of the dielectric material and a portion of the contact material to expose the top of the gate; recessing the contact material; removing the dielectric material; and patterning the contact material to form a self-aligned contact for the FET, the self-aligned contact being located over a source region and a drain region of the FET, the source region and the drain region comprising a second portion of the channel material.
    Type: Grant
    Filed: June 22, 2010
    Date of Patent: June 14, 2016
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Josephine Chang, Isaac Lauer, Jeffrey Sleight
  • Patent number: 9281397
    Abstract: A semiconductor device (e.g., field effect transistor (FET)) having an asymmetric feature, includes a first gate formed on a substrate, first and second diffusion regions formed in the substrate on a side of the first gate, and first and second contacts which contact the first and second diffusion regions, respectively, the first contact being asymmetric with respect to the second contact.
    Type: Grant
    Filed: January 17, 2014
    Date of Patent: March 8, 2016
    Assignee: GLOBALFOUNDRIES INC.
    Inventors: Josephine Chang, Isaac Lauer, Chung-Hsun Lin, Jeffrey Sleight
  • Patent number: 8877593
    Abstract: A semiconductor device (e.g., field effect transistor (FET)) having an asymmetric feature, includes a first gate formed on a substrate, first and second diffusion regions formed in the substrate on a side of the first gate, and first and second contacts which contact the first and second diffusion regions, respectively, the first contact being asymmetric with respect to the second contact.
    Type: Grant
    Filed: July 31, 2011
    Date of Patent: November 4, 2014
    Assignee: International Business Machines Corporation
    Inventors: Josephine Chang, Isaac Lauer, Chung-Hsun Lin, Jeffrey Sleight
  • Patent number: 8766410
    Abstract: Integrated circuits having combined memory and logic functions are provided. In one aspect, an integrated circuit is provided. The integrated circuit comprises: a substrate comprising a silicon layer over a BOX layer, wherein a select region of the silicon layer has a thickness of between about three nanometers and about 20 nanometers; at least one eDRAM cell comprising: at least one pass transistor having a pass transistor source region, a pass transistor drain region and a pass transistor channel region formed in the select region of the silicon layer; and a capacitor electrically connected to the pass transistor.
    Type: Grant
    Filed: June 6, 2011
    Date of Patent: July 1, 2014
    Assignee: International Business Machines Corporation
    Inventors: Jin Cai, Josephine Chang, Leland Chang, Brian L. Ji, Steven John Koester, Amlan Majumdar
  • Publication number: 20140131708
    Abstract: A semiconductor device (e.g., field effect transistor (FET)) having an asymmetric feature, includes a first gate formed on a substrate, first and second diffusion regions formed in the substrate on a side of the first gate, and first and second contacts which contact the first and second diffusion regions, respectively, the first contact being asymmetric with respect to the second contact.
    Type: Application
    Filed: January 17, 2014
    Publication date: May 15, 2014
    Applicant: International Business Machines Corporation
    Inventors: Josephine Chang, Isaac Lauer, Chung-Hsun Lin, Jeffrey Sleight
  • Publication number: 20130309837
    Abstract: Embodiments of the present invention provide a method of preventing electrical shorting of adjacent semiconductor devices. The method includes forming a plurality of fins of a plurality of field-effect-transistors on a substrate; forming at least one barrier structure between a first and a second fin of the plurality of fins; and growing an epitaxial film from the plurality of fins, the epitaxial film extending horizontally from sidewalls of at least the first and second fins and reaching the barrier structure situating between the first and second fins.
    Type: Application
    Filed: May 15, 2012
    Publication date: November 21, 2013
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: JOSEPHINE CHANG, MICHAEL A. GUILLORN, BALASUBRAMANIAN PRANATHARTHIHARAN, JEFFREY WILLIAM SLEIGHT
  • Patent number: 8586455
    Abstract: Embodiments of the present invention provide a method of preventing electrical shorting of adjacent semiconductor devices. The method includes forming a plurality of fins of a plurality of field-effect-transistors on a substrate; forming at least one barrier structure between a first and a second fin of the plurality of fins; and growing an epitaxial film from the plurality of fins, the epitaxial film extending horizontally from sidewalls of at least the first and second fins and reaching the barrier structure situating between the first and second fins.
    Type: Grant
    Filed: May 15, 2012
    Date of Patent: November 19, 2013
    Assignee: International Business Machines Corporation
    Inventors: Josephine Chang, Michael A. Guillorn, Balasubramanian Pranatharthiharan, Jeffrey William Sleight
  • Patent number: 8472239
    Abstract: Nanowire-based field-effect transistors (FETs) and techniques for the fabrication thereof are provided. In one aspect, a FET is provided having a plurality of device layers oriented vertically in a stack, each device layer having a source region, a drain region and a plurality of nanowire channels connecting the source region and the drain region, wherein one or more of the device layers are configured to have a different threshold voltage from one or more other of the device layers; and a gate common to each of the device layers surrounding the nanowire channels.
    Type: Grant
    Filed: May 9, 2012
    Date of Patent: June 25, 2013
    Assignee: International Business Machines Corporation
    Inventors: Josephine Chang, Paul Chang, Michael A. Guillorn, Jeffrey Sleight
  • Patent number: 8466451
    Abstract: A FET inverter is provided that includes a plurality of device layers oriented vertically in a stack, each device layer having a source region, a drain region and a plurality of nanowire channels, wherein the source and drain regions of one or more of the device layers are doped with an n-type dopant and the source and drain regions of one or more other of the device layers are doped with a p-type dopant; a gate common to each of the device layers surrounding the nanowire channels; a first contact to the source regions of the one or more device layers doped with an n-type dopant; a second contact to the source regions of the one or more device layers doped with a p-type dopant; and a third contact common to the drain regions of each of the device layers. Techniques for fabricating a FET inverter are also provided.
    Type: Grant
    Filed: December 11, 2011
    Date of Patent: June 18, 2013
    Assignee: International Business Machines Corporation
    Inventors: Josephine Chang, Paul Chang, Michael A. Guillorn, Jeffrey Sleight
  • Patent number: 8422273
    Abstract: Nanowire-based field-effect transistors (FETs) and techniques for the fabrication thereof are provided. In one aspect, a FET is provided having a plurality of device layers oriented vertically in a stack, each device layer having a source region, a drain region and a plurality of nanowire channels connecting the source region and the drain region, wherein one or more of the device layers are configured to have a different threshold voltage from one or more other of the device layers; and a gate common to each of the device layers surrounding the nanowire channels.
    Type: Grant
    Filed: May 21, 2009
    Date of Patent: April 16, 2013
    Assignee: International Business Machines Corporation
    Inventors: Josephine Chang, Paul Chang, Michael A. Guillorn, Jeffrey Sleight
  • Patent number: 8395220
    Abstract: Nanowire-based devices are provided. In one aspect, a SRAM cell includes at least one pair of pass gates and at least one pair of inverters formed adjacent to one another on a wafer. Each pass gate includes one or more device layers each having a source region, a drain region and a plurality of nanowire channels connecting the source region and the drain region and a gate common to each of the pass gate device layers surrounding the nanowire channels. Each inverter includes a plurality of device layers each having a source region, a drain region and a plurality of nanowire channels connecting the source region and the drain region and a gate common to each of the inverter device layers surrounding the nanowire channels.
    Type: Grant
    Filed: March 12, 2012
    Date of Patent: March 12, 2013
    Assignee: International Business Machines Corporation
    Inventors: Josephine Chang, Paul Chang, Michael A. Guillorn, Jeffrey Sleight
  • Publication number: 20130026465
    Abstract: A semiconductor device (e.g., field effect transistor (FET)) having an asymmetric feature, includes a first gate formed on a substrate, first and second diffusion regions formed in the substrate on a side of the first gate, and first and second contacts which contact the first and second diffusion regions, respectively, the first contact being asymmetric with respect to the second contact.
    Type: Application
    Filed: July 31, 2011
    Publication date: January 31, 2013
    Applicant: International Business Machines Corporation
    Inventors: Josephine Chang, Isaac Lauer, Chung-Hsun Lin, Jeffrey Sleight
  • Publication number: 20120298949
    Abstract: A field effect transistor (FET) includes a substrate; a channel material located on the substrate, the channel material comprising one of graphene or a nanostructure; a gate located on a first portion of the channel material; and a contact aligned to the gate, the contact comprising one of a metal silicide, a metal carbide, and a metal, the contact being located over a source region and a drain region of the FET, the source region and the drain region comprising a second portion of the channel material.
    Type: Application
    Filed: August 9, 2012
    Publication date: November 29, 2012
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Josephine Chang, Isaac Lauer, Jeffrey Sleight
  • Publication number: 20120217479
    Abstract: Nanowire-based field-effect transistors (FETs) and techniques for the fabrication thereof are provided. In one aspect, a FET is provided having a plurality of device layers oriented vertically in a stack, each device layer having a source region, a drain region and a plurality of nanowire channels connecting the source region and the drain region, wherein one or more of the device layers are configured to have a different threshold voltage from one or more other of the device layers; and a gate common to each of the device layers surrounding the nanowire channels.
    Type: Application
    Filed: May 9, 2012
    Publication date: August 30, 2012
    Applicant: Internatiional Business Machines Corporation
    Inventors: Josephine Chang, Paul Chang, Michael A. Guillorn, Jeffrey Sleight
  • Patent number: 8216902
    Abstract: Nanowire-based devices are provided. In one aspect, a SRAM cell includes at least one pair of pass gates and at least one pair of inverters formed adjacent to one another on a wafer. Each pass gate includes one or more device layers each having a source region, a drain region and a plurality of nanowire channels connecting the source region and the drain region and a gate common to each of the pass gate device layers surrounding the nanowire channels. Each inverter includes a plurality of device layers each having a source region, a drain region and a plurality of nanowire channels connecting the source region and the drain region and a gate common to each of the inverter device layers surrounding the nanowire channels.
    Type: Grant
    Filed: August 6, 2009
    Date of Patent: July 10, 2012
    Assignee: International Business Machines Corporation
    Inventors: Josephine Chang, Paul Chang, Michael A. Guillorn, Jeffrey Sleight