Patents by Inventor Chung H. Lam

Chung H. Lam 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: 11968913
    Abstract: A method for fabricating a semiconductor device includes forming air gaps within respective dielectric layer portions to reduce thermal cross-talk between adjacent bits. Each of the dielectric portions is formed on a substrate each adjacent to sidewall liners formed on sidewalls of a phase change memory (PCM) layer. The method further includes forming a pillar including the sidewall liners and the PCM layer, and forming a selector layer on the pillar and the dielectric portions.
    Type: Grant
    Filed: July 28, 2022
    Date of Patent: April 23, 2024
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Wanki Kim, Fabio Carta, Chung H. Lam, Robert L. Bruce
  • Publication number: 20220367797
    Abstract: A method for fabricating a semiconductor device includes forming air gaps within respective dielectric layer portions to reduce thermal cross-talk between adjacent bits. Each of the dielectric portions is formed on a substrate each adjacent to sidewall liners formed on sidewalls of a phase change memory (PCM) layer. The method further includes forming a pillar including the sidewall liners and the PCM layer, and forming a selector layer on the pillar and the dielectric portions.
    Type: Application
    Filed: July 28, 2022
    Publication date: November 17, 2022
    Inventors: Wanki Kim, Fabio Carta, Chung H. Lam, Robert L. Bruce
  • Patent number: 11437571
    Abstract: A method for fabricating a semiconductor device includes forming air gaps within respective dielectric layer portions to reduce thermal cross-talk between adjacent bits. Each of the dielectric portions is formed on a substrate each adjacent to sidewall liners formed on sidewalls of a phase change memory (PCM) layer. The method further includes forming a pillar including the sidewall liners and the PCM layer, and forming a selector layer on the pillar and the dielectric portions.
    Type: Grant
    Filed: June 25, 2019
    Date of Patent: September 6, 2022
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Wanki Kim, Fabio Carta, Chung H. Lam, Robert L. Bruce
  • Patent number: 11270192
    Abstract: One embodiment relates to a neuromorphic network including electronic neurons and an interconnect circuit for interconnecting the neurons. The interconnect circuit includes synaptic devices for interconnecting the neurons via axon paths, dendrite paths and membrane paths. Each synaptic device includes a variable state resistor and a transistor device with a gate terminal, a source terminal and a drain terminal, wherein the drain terminal is connected in series with a first terminal of the variable state resistor. The source terminal of the transistor device is connected to an axon path, the gate terminal of the transistor device is connected to a membrane path and a second terminal of the variable state resistor is connected to a dendrite path, such that each synaptic device is coupled between a first axon path and a first dendrite path, and between a first membrane path and said first dendrite path.
    Type: Grant
    Filed: March 9, 2018
    Date of Patent: March 8, 2022
    Assignee: International Business Machines Corporation
    Inventors: Daniel J. Friedman, Seongwon Kim, Chung H. Lam, Dharmendra S. Modha, Bipin Rajendran, Jose A. Tierno
  • Patent number: 11232345
    Abstract: One embodiment relates to a neuromorphic network including electronic neurons and an interconnect circuit for interconnecting the neurons. The interconnect circuit includes synaptic devices for interconnecting the neurons via axon paths, dendrite paths and membrane paths. Each synaptic device includes a variable state resistor and a transistor device with a gate terminal, a source terminal and a drain terminal, wherein the drain terminal is connected in series with a first terminal of the variable state resistor. The source terminal of the transistor device is connected to an axon path, the gate terminal of the transistor device is connected to a membrane path and a second terminal of the variable state resistor is connected to a dendrite path, such that each synaptic device is coupled between a first axon path and a first dendrite path, and between a first membrane path and said first dendrite path.
    Type: Grant
    Filed: March 9, 2018
    Date of Patent: January 25, 2022
    Assignee: International Business Machines Corporation
    Inventors: Daniel J. Friedman, Seongwon Kim, Chung H. Lam, Dharmendra S. Modha, Bipin Rajendran, Jose A. Tierno
  • Patent number: 11152063
    Abstract: Structures and methods for a multi-bit phase change memory are disclosed herein. A method includes establishing a write-reference voltage that incrementally ramps over a write period. The increments of the write-reference voltage correspond to discrete resistance states of a storage cell of the multi-bit phase change memory.
    Type: Grant
    Filed: July 30, 2019
    Date of Patent: October 19, 2021
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Chung H. Lam, Scott C. Lewis, Thomas M. Maffitt, Jack Morrish
  • Patent number: 10998045
    Abstract: Structures and methods for a multi-bit phase change memory are provided herein. A method includes establishing a write-reference voltage that incrementally ramps over a write period. The increments of the write-reference voltage correspond to discrete resistance states of a storage cell of the multi-bit phase change memory.
    Type: Grant
    Filed: November 11, 2019
    Date of Patent: May 4, 2021
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Chung H. Lam, Scott C. Lewis, Thomas M. Maffitt, Jack Morrish
  • Patent number: 10943658
    Abstract: Structures and methods for a multi-bit phase change memory, are provided herein. A method includes establishing a write-reference voltage that incrementally ramps over a write period. The increments of the write-reference voltage correspond to discrete resistance states of a storage cell of the multi-bit phase change memory.
    Type: Grant
    Filed: November 11, 2019
    Date of Patent: March 9, 2021
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Chung H. Lam, Scott C. Lewis, Thomas M. Maffitt, Jack Morrish
  • Patent number: 10937496
    Abstract: Structures and methods for a multi-bit phase change memory are disclosed herein. A method includes establishing a write-reference voltage that incrementally ramps over a write period. The increments of the write-reference voltage correspond to discrete resistance states of a storage cell of the multi-bit phase change memory.
    Type: Grant
    Filed: July 30, 2019
    Date of Patent: March 2, 2021
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Chung H. Lam, Scott C. Lewis, Thomas M. Maffitt, Jack Morrish
  • Patent number: 10930705
    Abstract: A method is presented for integrating an electronic component in back end of the line (BEOL) processing. The method includes forming a first electrode over a semiconductor substrate, forming a first electrically conductive material over a portion of the first electrode, forming a second electrically conductive material over the first electrically conductive material, where the first and second electrically conductive materials define a p-n junction, depositing a phase change material over the p-n junction, and forming a second electrode over the phase change material.
    Type: Grant
    Filed: March 28, 2018
    Date of Patent: February 23, 2021
    Assignee: International Business Machines Corporation
    Inventors: Fabio Carta, Chung H. Lam, Matthew J. BrightSky, Bahman Hekmatshoartabari
  • Patent number: 10892413
    Abstract: A phase change memory array and method for fabricating the same. The phase change memory array includes a plurality of bottom electrodes, top electrodes, and memory pillars. Each of the memory pillars includes phase change material surrounded by a dielectric casing. The phase change material is positioned between, and in series circuit with, a respective bottom electrode from the bottom electrodes and a respective top electrode from the top electrodes. A continuous layer of selector material is positioned between the memory pillars and the plurality of bottom electrodes. The selector material is configured to conduct electricity only when a voltage across the selector material exceeds a voltage threshold.
    Type: Grant
    Filed: January 17, 2017
    Date of Patent: January 12, 2021
    Assignee: International Business Machines Corporation
    Inventors: Robert L. Bruce, Fabio Carta, Wanki Kim, Chung H. Lam
  • Publication number: 20200411757
    Abstract: A method for fabricating a semiconductor device includes forming air gaps within respective dielectric layer portions to reduce thermal cross-talk between adjacent bits. Each of the dielectric portions is formed on a substrate each adjacent to sidewall liners formed on sidewalls of a phase change memory (PCM) layer. The method further includes forming a pillar including the sidewall liners and the PCM layer, and forming a selector layer on the pillar and the dielectric portions.
    Type: Application
    Filed: June 25, 2019
    Publication date: December 31, 2020
    Inventors: Wanki Kim, Fabio Carta, Chung H. Lam, Robert L. Bruce
  • Patent number: 10833123
    Abstract: A method for deactivating memory cells affected by the presence of grain boundaries in polycrystalline selection devices includes crystallizing a semiconductor layer in a diode stack to form a polycrystalline layer for selection diodes formed in a crossbar array. To achieve a crystalline state in phase change memory elements coupled to corresponding selection diodes perform an anneal. Memory cells having shunted selection diodes due to grain boundaries are identified by scanning the array using sense voltages. A second voltage larger than the sense voltages is applied to the phase change memory elements gated by the shunted selection diodes such that the phase change memory elements gated by the shunted diodes achieve a permanently high resistive state.
    Type: Grant
    Filed: January 15, 2019
    Date of Patent: November 10, 2020
    Assignee: International Business Machines Corporation
    Inventors: Bahman Hekmatshoartabari, Chung H. Lam, Fabio Carta, Matthew J. BrightSky
  • Patent number: 10810489
    Abstract: A neuromorphic memory system including neuromorphic memory arrays. The neuromorphic memory system includes a presynaptic neuron circuit coupled to a postsynaptic neuron circuit by a resistive memory cell. The method includes generating a presynaptic LIF pulse on a presynaptic LIF line at time t1. An activating operation activates an access transistor coupled to the presynaptic LIF line in response to the presynaptic LIF pulse. The access transistor enables LIF current to pass through the resistive memory cell to a postsynaptic LIF line. An integrating operation integrates the LIF current at the postsynaptic LIF line over time. A comparing operation compares a LIF voltage at the postsynaptic LIF line to a threshold voltage. A generating operation generates a postsynaptic spike timing dependent plasticity (STDP) pulse on a postsynaptic STDP line if the LIF voltage is beyond the threshold voltage.
    Type: Grant
    Filed: November 12, 2019
    Date of Patent: October 20, 2020
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Kohji Hosokawa, Masatoshi Ishii, SangBum Kim, Chung H. Lam, Scott C. Lewis
  • Patent number: 10763374
    Abstract: A method is presented for integrating an electronic component in back end of the line (BEOL) processing. The method includes forming a first electrode over a semiconductor substrate, forming a first electrically conductive material over a portion of the first electrode, and forming a second electrically conductive material over the first electrically conductive material, where the first and second electrically conductive materials define a p-n junction. The method further includes depositing a second electrode between a set of spacers and in direct contact with the p-n-junction, depositing a phase change material over the p-n junction and in direct contact with the second electrode, and forming a third electrode over a portion of the phase change material.
    Type: Grant
    Filed: May 16, 2019
    Date of Patent: September 1, 2020
    Assignee: International Business Machines Corporation
    Inventors: Fabio Carta, Chung H. Lam, Matthew J. BrightSky, Bahman Hekmatshoartabari
  • Patent number: 10762959
    Abstract: Structures and methods for a multi-bit phase change memory are disclosed herein. A method includes establishing a write-reference voltage that incrementally ramps over a write period. The increments of the write-reference voltage correspond to discrete resistance states of a storage cell of the multi-bit phase change memory.
    Type: Grant
    Filed: May 25, 2018
    Date of Patent: September 1, 2020
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Chung H. Lam, Scott C. Lewis, Thomas M. Maffitt, Jack Morrish
  • Patent number: 10713562
    Abstract: A neuromorphic memory circuit including a programmable resistive memory element, an axon LIF pulse generator to generate an axon LIF pulse, a back propagation pulse generator to generate a back propagation pulse, a postsynaptic capacitor configured to build up a forward propagation LIF charge over time, and a presynaptic capacitor configured to build up a back propagation LIF charge over time. A first transistor activates a first discharge path from the postsynaptic capacitor through the programmable resistive memory element when the axon LIF pulse generator generates the axon LIF pulse. A second transistor activates a second discharge path from the presynaptic capacitor through the programmable resistive memory element when the back propagation pulse generator generates the back propagation pulse.
    Type: Grant
    Filed: June 18, 2016
    Date of Patent: July 14, 2020
    Assignee: International Business Machines Corporation
    Inventors: SangBum Kim, Chung H. Lam
  • Patent number: 10692576
    Abstract: Structures and methods for a multi-bit phase change memory are disclosed herein. A method includes establishing a write-reference voltage that incrementally ramps over a write period. The increments of the write-reference voltage correspond to discrete resistance states of a storage cell of the multi-bit phase change memory.
    Type: Grant
    Filed: May 14, 2019
    Date of Patent: June 23, 2020
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Chung H. Lam, Scott C. Lewis, Thomas M. Maffitt, Jack Morrish
  • Publication number: 20200082256
    Abstract: A neuromorphic memory system including neuromorphic memory arrays. The neuromorphic memory system includes a presynaptic neuron circuit coupled to a postsynaptic neuron circuit by a resistive memory cell. The method includes generating a presynaptic LIF pulse on a presynaptic LIF line at time t1. An activating operation activates an access transistor coupled to the presynaptic LIF line in response to the presynaptic LIF pulse. The access transistor enables LIF current to pass through the resistive memory cell to a postsynaptic LIF line. An integrating operation integrates the LIF current at the postsynaptic LIF line over time. A comparing operation compares a LIF voltage at the postsynaptic LIF line to a threshold voltage. A generating operation generates a postsynaptic spike timing dependent plasticity (STDP) pulse on a postsynaptic STDP line if the LIF voltage is beyond the threshold voltage.
    Type: Application
    Filed: November 12, 2019
    Publication date: March 12, 2020
    Inventors: Kohji Hosokawa, Masatoshi Ishii, SangBum Kim, Chung H. Lam, Scott C. Lewis
  • Publication number: 20200075097
    Abstract: Structures and methods for a multi-bit phase change memory are disclosed herein. A method includes establishing a write-reference voltage that incrementally ramps over a write period. The increments of the write-reference voltage correspond to discrete resistance states of a storage cell of the multi-bit phase change memory.
    Type: Application
    Filed: November 11, 2019
    Publication date: March 5, 2020
    Inventors: Chung H. Lam, Scott C. Lewis, Thomas M. Maffitt, Jack Morrish