Patents by Inventor Karthik Balakrishnan

Karthik Balakrishnan 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: 11081569
    Abstract: A method of forming an electrical device is provided that includes a semiconductor device and a passive resistor both integrated in a same vertically orientated epitaxially grown semiconductor material. The vertically orientated epitaxially grown semiconductor material is formed from a semiconductor surface of a supporting substrate. The vertically orientated epitaxially grown semiconductor material includes a resistive portion and a semiconductor portion, in which the sidewalls of the resistive portion are aligned with the sidewalls of the semiconductor portion. A semiconductor device is formed on the semiconductor portion of the vertically orientated epitaxially grown semiconductor material. A passive resistor is present in the resistive portion of the vertically orientated epitaxially grown semiconductor material, the resistive portion having a higher resistance than the semiconductor portion.
    Type: Grant
    Filed: December 15, 2017
    Date of Patent: August 3, 2021
    Assignee: International Business Machines Corporation
    Inventors: Karthik Balakrishnan, Bahman Hekmatshoartabari, Tak H. Ning, Alexander Reznicek
  • Patent number: 11061146
    Abstract: A semiconductor radiation monitor is provided that includes a charge storage region composed of a dielectric material nanosheet, such as, for example an epitaxial oxide nanosheet, which is sandwiched between a top semiconductor nanosheet and a bottom semiconductor nanosheet. A functional gate structure is located above the top semiconductor nanosheet and beneath the bottom semiconductor nanosheet.
    Type: Grant
    Filed: January 24, 2019
    Date of Patent: July 13, 2021
    Assignee: International Business Machines Corporation
    Inventors: Jeng-Bang Yau, Alexander Reznicek, Karthik Balakrishnan, Bahman Hekmatshoartabari
  • Publication number: 20210193923
    Abstract: A one-transistor-two-resistor (1T2R) resistive random access memory (ReRAM) structure, and a method for forming the same, includes forming a vertical field effect transistor (VFET) including an epitaxial region located above a channel region and below a dielectric cap. The epitaxial region includes two opposing protruding regions of triangular shape bounded by <111> planes that extend horizontally beyond the channel region. A ReRAM stack is conformally deposited on the VFET. The ReRAM stack includes an oxide layer located directly above the epitaxial region, a top electrode layer directly above the oxide layer and a metal fill above the top electrode layer. Each of the two opposing protruding regions of the epitaxial region acts as a bottom electrode for the ReRAM stack.
    Type: Application
    Filed: December 20, 2019
    Publication date: June 24, 2021
    Inventors: Alexander Reznicek, Bahman Hekmatshoartabari, Takashi Ando, Karthik Balakrishnan
  • Patent number: 11043587
    Abstract: A vertical fin field effect transistor including a doped region in a substrate, wherein the doped region has the same crystal orientation as the substrate, a first portion of a vertical fin on the doped region, wherein the first portion of the vertical fin has the same crystal orientation as the substrate and a first portion width, a second portion of the vertical fin on the first portion of the vertical fin, wherein the second portion of the vertical fin has the same crystal orientation as the first portion of the vertical fin, and the second portion of the vertical fin has a second portion width less than the first portion width, a gate structure on the second portion of the vertical fin, and a source/drain region on the top of the second portion of the vertical fin.
    Type: Grant
    Filed: October 13, 2017
    Date of Patent: June 22, 2021
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Karthik Balakrishnan, Kangguo Cheng, Pouya Hashemi, Alexander Reznicek
  • Publication number: 20210175354
    Abstract: A first vertical T-FET has a source heavily doped with a source concentration of a source-type dopant, a drain doped with a drain concentration of a drain-type dopant, and a channel between the source and drain. The source, channel, and drain are stacked vertically in a fin or pillar perpendicular to a substrate. A gate stack encompasses the channel sides and has a drain overlap amount overlapping the drain sides and a source overlap amount overlapping the source sides. External contacts electrically connect the gate and source and/or drain. The source-type dopant and the drain-type dopant are opposite dopant types. In some embodiments, a second vertical T-FET is stacked on the first vertical T-FET. Different VT-FET devices are made by changing the materials, doping types and levels, and connections to the sources, channels, and drains. Device characteristics are designed/changed by changing the amount of source and drain overlaps of the gate stack(s).
    Type: Application
    Filed: December 6, 2019
    Publication date: June 10, 2021
    Inventors: Karthik Balakrishnan, Bahman Hekmatshoartabari, Alexander Reznicek
  • Patent number: 11031297
    Abstract: Various embodiments disclose a method for fabricating a semiconductor structure. In one embodiment, the method includes forming a masking layer over at least a first portion of a source contact layer formed on a substrate. At least a second portion of the source contact layer is recessed below the first portion of the source contact layer. The mask layer is removed and a first spacer layer, a replacement gate on the first spacer layer, a second spacer layer on the replacement gate, and an insulating layer on the second spacer layer are formed. First and second trenches are then formed. A first channel layer is epitaxially grown within the first trench. A second channel layer is epitaxially grown within the second trench. A length of the second channel layer is greater than a length of the first channel layer.
    Type: Grant
    Filed: March 28, 2018
    Date of Patent: June 8, 2021
    Assignee: International Business Machines Corporation
    Inventors: Karthik Balakrishnan, Kangguo Cheng, Pouya Hashemi, Alexander Reznicek
  • Publication number: 20210167129
    Abstract: A semiconductor structure may include two vertical transport field effect transistors comprising a top source drain, a bottom source drain, and an epitaxial channel and a resistive random access memory between the two vertical transport field effect transistors, the resistive random access memory may include an oxide layer, a top electrode, and a bottom electrode, wherein the oxide layer may contact the top source drain of the two vertical field effect transistor. The top source drain may function as the bottom electrode of the resistive random access memory. The semiconductor structure may include a shallow trench isolation between the two vertical transport field effect transistors, the shallow trench isolation may be embedded in a first spacer, a doped source, and a portion of a substrate.
    Type: Application
    Filed: December 3, 2019
    Publication date: June 3, 2021
    Inventors: Alexander Reznicek, Karthik Balakrishnan, Bahman Hekmatshoartabari, Takashi Ando
  • Patent number: 11018254
    Abstract: A vertical fin field effect transistor including a doped region in a substrate, wherein the doped region has the same crystal orientation as the substrate, a first portion of a vertical fin on the doped region, wherein the first portion of the vertical fin has the same crystal orientation as the substrate and a first portion width, a second portion of the vertical fin on the first portion of the vertical fin, wherein the second portion of the vertical fin has the same crystal orientation as the first portion of the vertical fin, and the second portion of the vertical fin has a second portion width less than the first portion width, a gate structure on the second portion of the vertical fin, and a source/drain region on the top of the second portion of the vertical fin.
    Type: Grant
    Filed: March 31, 2016
    Date of Patent: May 25, 2021
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Karthik Balakrishnan, Kangguo Cheng, Pouya Hashemi, Alexander Reznicek
  • Publication number: 20210151449
    Abstract: A method for manufacturing a semiconductor device includes forming a first vertical transistor on a semiconductor substrate, and forming a second vertical transistor stacked on the first vertical transistor. In the method, a silicide layer is formed on a first drain region of the first vertical transistor and on a second drain region of the second vertical transistor. The silicide layer electrically connects the first and second drain regions to each other.
    Type: Application
    Filed: December 23, 2020
    Publication date: May 20, 2021
    Inventors: Alexander Reznicek, Karthik Balakrishnan, Tak Ning, Bahman Hekmatshoartabari
  • Patent number: 10998444
    Abstract: A stacked FinFET mask-programmable read only memory (ROM) is provided. The stacked FinFET mask-programmable ROM includes a fin structure extending upward from an insulator layer. In accordance with the present application, the fin structure includes, from bottom to top, a lower programmable semiconductor fin portion having a first threshold voltage, an insulator fin portion, and an upper programmable semiconductor fin portion having a second threshold voltage. A lower gate structure contacts a sidewall of the lower programmable semiconductor fin portion, and an upper gate structure contacts a sidewall of the upper programmable semiconductor fin portion.
    Type: Grant
    Filed: February 11, 2019
    Date of Patent: May 4, 2021
    Assignee: International Business Machines Corporation
    Inventors: Alexander Reznicek, Karthik Balakrishnan, Tak Ning, Bahman Hekmatshoartabari
  • Patent number: 10991823
    Abstract: A vertical fin field effect transistor including a doped region in a substrate, wherein the doped region has the same crystal orientation as the substrate, a first portion of a vertical fin on the doped region, wherein the first portion of the vertical fin has the same crystal orientation as the substrate and a first portion width, a second portion of the vertical fin on the first portion of the vertical fin, wherein the second portion of the vertical fin has the same crystal orientation as the first portion of the vertical fin, and the second portion of the vertical fin has a second portion width less than the first portion width, a gate structure on the second portion of the vertical fin, and a source/drain region on the top of the second portion of the vertical fin.
    Type: Grant
    Filed: October 13, 2017
    Date of Patent: April 27, 2021
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Karthik Balakrishnan, Kangguo Cheng, Pouya Hashemi, Alexander Reznicek
  • Patent number: 10991711
    Abstract: Semiconductor structures and methods of making the same. The semiconductor structures including at least two vertically stacked nanosheet devices. In one embodiment, an integrated circuit includes a plurality of horizontal nanosheet devices (HNS devices) that are stacked vertically, on top of each other, relative to a top surface of a substrate. The plurality of HNS devices including a first HNS device and a second HNS device that each have source and drain structures.
    Type: Grant
    Filed: June 20, 2019
    Date of Patent: April 27, 2021
    Assignee: International Business Machines Corporation
    Inventors: Alexander Reznicek, Bahman Hekmatshoartabari, Karthik Balakrishnan, Jeng-Bang Yau
  • Patent number: 10964709
    Abstract: A method for integrating a stack of fins to form an electrically erasable programmable read-only memory (EEPROM) device is presented. The method includes forming a stack of at least a first fin structure and a second fin structure over a semiconductor substrate, forming a sacrificial gate straddling the stack of at least the first fin structure and the second fin structure, forming a first conductivity type source/drain region to the first fin structure, and forming a second conductivity type source/drain to the second fin structure. The method further includes removing the sacrificial gate to form a gate opening, and forming a single floating gate in communication with a channel for each of the first and second fin structures.
    Type: Grant
    Filed: March 13, 2019
    Date of Patent: March 30, 2021
    Assignee: International Business Machines Corporation
    Inventors: Karthik Balakrishnan, Pouya Hashemi, Tak H. Ning, Alexander Reznicek
  • Patent number: 10957694
    Abstract: A method of forming a semiconductor device that includes providing regions of epitaxial oxide material on a substrate of a first lattice dimension, wherein regions of the epitaxial oxide material separate regions of epitaxial semiconductor material having a second lattice dimension are different than the first lattice dimension to provide regions of strained semiconductor. The regions of the strained semiconductor material are patterned to provide regions of strained fin structures. The epitaxial oxide that is present in the gate cut space obstructs relaxation of the strained fin structures. A gate structure is formed on a channel region of the strained fin structures separating source and drain regions of the fin structures.
    Type: Grant
    Filed: January 24, 2019
    Date of Patent: March 23, 2021
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Karthik Balakrishnan, Keith E. Fogel, Sivananda K. Kanakasabapathy, Alexander Reznicek
  • Patent number: 10957707
    Abstract: The dosimeter has two vertical field effect transistors (VFETs), each VFET with a bottom and top source/drain and channel between them. An implanted charge storage region material lies between and in contact with each of the vertical channels. A trapped charge is within the implanted charge storage region. The amount of the trapped charge is related to an amount of radiation that passes through the implanted charge storage region.
    Type: Grant
    Filed: April 23, 2019
    Date of Patent: March 23, 2021
    Assignee: International Business Machines Corporation
    Inventors: Jeng-Bang Yau, Alexander Reznicek, Bahman Hekmatshoartabari, Karthik Balakrishnan
  • Publication number: 20210083139
    Abstract: A semiconductor radiation monitor (i.e., dosimeter) is provided that has an oxide charge storage region located on a first side of a semiconductor fin and a functional gate structure located on a second side of the semiconductor fin that is opposite the first side. Charges are created in the oxide charge storage region that is located on the first side of the semiconductor fin and detected on the second side of the semiconductor fin by the functional gate structure. Multiple semiconductor fins in parallel can form a dense and very sensitive semiconductor radiation monitor.
    Type: Application
    Filed: September 16, 2019
    Publication date: March 18, 2021
    Inventors: Alexander Reznicek, Bahman Hekmatshoartabari, Jeng-Bang Yau, Karthik Balakrishnan
  • Patent number: 10944012
    Abstract: An inverter that includes an n-type field effect transistor (nFET) and a p-type field effect transistor (pFET) vertically stacked one atop the other and containing a buried metal semiconductor alloy strap that connects a drain region of the nFET to a drain region of the pFET is provided. Also, provided is a cross-coupled inverter pair with nFETs and pFETs stacked vertically.
    Type: Grant
    Filed: January 2, 2019
    Date of Patent: March 9, 2021
    Assignee: International Business Machines Corporation
    Inventors: Alexander Reznicek, Kangguo Cheng, Karthik Balakrishnan, Pouya Hashemi
  • Patent number: 10937903
    Abstract: A semiconductor diode including a first conductivity type region on an upper surface of a semiconductor substrate, a fin structure atop the first conductivity type region providing a vertically orientated semiconductor base region, and a second conductivity type region at a second end of the fin structure opposite a first end of the fin structure that is in contact with the first conductivity type region. The semiconductor diode may also include a vertically orientated dual gate that is present around the fin structure. The vertically orientated dual gate including a first gate structure that is present abutting the semiconductor substrate and a second gate structure that is in closer proximity to the second conductivity type region than the first conductivity type region. The first gate structure separated from the second gate structure by a dielectric inter-gate spacer.
    Type: Grant
    Filed: January 18, 2019
    Date of Patent: March 2, 2021
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Karthik Balakrishnan, Pouya Hashemi, Bahman Hekmatshoartabari, Alexander Reznicek
  • Patent number: 10937898
    Abstract: A structure and method of forming a lateral bipolar junction transistor (LBJT) that includes: a first base layer, a second base layer over the first base layer, and an emitter region and collector region present on opposing sides of the first base layer, where the first base layer has a wider-band gap than the second base layer, and where the first base layer includes a III-V semiconductor material.
    Type: Grant
    Filed: August 14, 2019
    Date of Patent: March 2, 2021
    Assignee: International Business Machines Corporation
    Inventors: Pouya Hashemi, Bahman Hekmatshoartabari, Alexander Reznicek, Karthik Balakrishnan, Jeng-Bang Yau
  • Patent number: 10930779
    Abstract: A semiconductor device including a fin structure present on a supporting substrate to provide a vertically orientated channel region. A first source/drain region having a first epitaxial material with a diamond shaped geometry is present at first end of the fin structure that is present on the supporting substrate. A second source/drain region having a second epitaxial material with said diamond shaped geometry that is present at the second end of the fin structure. A same geometry for the first and second epitaxial material of the first and second source/drain regions provides a symmetrical device.
    Type: Grant
    Filed: October 31, 2019
    Date of Patent: February 23, 2021
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Karthik Balakrishnan, Kangguo Cheng, Pouya Hashemi, Alexander Reznicek