Patents by Inventor Kangho Lee

Kangho Lee 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: 20160126453
    Abstract: Perpendicular magnetic anisotropy (PMA) type magnetic random access memory cells are constructed with a composite PMA layer to provide a magnetic tunnel junction (MTJ) with an acceptable thermal barrier. A PMA coupling layer is deposited between a first PMA layer and a second PMA layer to form the composite PMA layer. The composite PMA layer may be incorporated in PMA type MRAM cells or in-plane type MRAM cells.
    Type: Application
    Filed: January 13, 2016
    Publication date: May 5, 2016
    Inventors: Wei-Chuan CHEN, Kangho LEE, Xiaochun ZHU, Seung H. KANG
  • Publication number: 20160116611
    Abstract: A method and apparatus for detecting an X-ray, the apparatus includes a detector which comprises a pixel array in which a plurality of pixels for detecting an X-ray transmitted by a body to be examined are arranged in a matrix form, a read-out unit which reads out electrical signals corresponding to the detected X-ray from the pixel array, and a reset controller which controls the pixel array to be reset after the X ray is detected, by performing switching so that the plurality of pixels of the pixel array are commonly connected to the reset power source.
    Type: Application
    Filed: June 19, 2015
    Publication date: April 28, 2016
    Inventors: Young KIM, Jaechul PARK, Kangho LEE
  • Publication number: 20160116612
    Abstract: Disclosed is a method of driving a radiation detection apparatus using a variable voltage applying scheme. In the method, different voltages are applied in a standby step, where radiation is not irradiated onto the radiation detection apparatus, and an irradiation step where the radiation is irradiated. A voltage which is applied in the standby step has an absolute value lower than a voltage which is applied in the irradiation step, and is set to minimize a dark current which is generated in a photoconductor layer of the radiation detection apparatus in the standby step.
    Type: Application
    Filed: July 23, 2015
    Publication date: April 28, 2016
    Inventors: Kangho LEE, Jinmyoung KIM, Jaechul PARK
  • Patent number: 9324939
    Abstract: A magnetic tunnel junction (MTJ) device in a magnetoresistive random access memory (MRAM) and method of making the same are provided to achieve a high tunneling magnetoresistance (TMR), a high perpendicular magnetic anisotropy (PMA), good data retention, and a high level of thermal stability. The MTJ device includes a first free ferromagnetic layer, a synthetic antiferromagnetic (SAF) coupling layer, and a second free ferromagnetic layer, where the first and second free ferromagnetic layers have opposite magnetic moments.
    Type: Grant
    Filed: July 1, 2014
    Date of Patent: April 26, 2016
    Assignee: QUALCOMM Incorporated
    Inventors: Chando Park, Matthias Georg Gottwald, Kangho Lee, Seung Hyuk Kang
  • Publication number: 20160111634
    Abstract: A perpendicular magnetic tunnel junction (MTJ) apparatus includes a tunnel magnetoresistance (TMR) enhancement buffer layer deposited between the tunnel barrier layer and the reference layers. An amorphous alloy spacer is deposited between the TMR enhancement buffer layer and the reference layers to enhance TMR. The amorphous alloy spacer blocks template effects of face centered cubic (fcc) oriented pinned layers and provides strong coupling between the pinned layers and the TMR enhancement buffer layer to ensure full perpendicular magnetization.
    Type: Application
    Filed: November 13, 2015
    Publication date: April 21, 2016
    Inventors: Kangho Lee, Wei-Chuan Chen, Seung Kang
  • Patent number: 9298946
    Abstract: One feature pertains to a method of implementing a physically unclonable function that includes providing an array of metal-insulator-metal (MIM) devices, where the MIM devices are configured to represent a first resistance state or a second resistance state and a plurality of the MIM devices are initially at the first resistance state. The MIM devices have a random breakdown voltage that is greater than a first voltage and less than a second voltage, where the breakdown voltage represents a voltage that causes the MIM devices to transition from the first resistance state to the second resistance state. The method further includes applying a signal line voltage to the MIM devices to cause a portion of the MIM devices to randomly breakdown and transition from the first resistance state to the second resistance state, the signal line voltage greater than the first voltage and less than the second voltage.
    Type: Grant
    Filed: November 5, 2013
    Date of Patent: March 29, 2016
    Assignee: QUALCOMM Incorporated
    Inventors: Xiaochun Zhu, Steven M. Millendorf, Xu Guo, David M. Jacobson, Kangho Lee, Seung H. Kang, Matthew Michael Nowak
  • Publication number: 20160072043
    Abstract: A magnetic tunnel junction (MTJ) device includes a pinned layer, a tunnel barrier layer on the pinned layer, and a free layer on the tunnel barrier layer. The MTJ device also includes a perpendicular magnetic anisotropic (PMA) enhancement layer on the free layer, a capping layer on the PMA enhancement layer, and a conductive path electrically shorting the capping layer, the PMA enhancement layer and the free layer. A method of fabricating a perpendicular magnetic tunnel junction (pMTJ) device includes forming a capping layer, a perpendicular magnetic anisotropic (PMA) enhancement layer and a free layer. The method also includes forming a conductive layer to short the capping layer, the PMA enhancement layer and the free layer.
    Type: Application
    Filed: September 10, 2014
    Publication date: March 10, 2016
    Inventors: Chando PARK, Kangho LEE, Jimmy KAN, Matthias Georg Gottwald, Xiaochun ZHU, Seung Hyuk KANG
  • Publication number: 20160041275
    Abstract: A radiation detector and a method of operating the radiation detector. The radiation detector includes: a photoconductive layer between the array substrate and the counter electrode and having a particle-in-binder (PIB) structure in which a photoconductive particle and a binder are mixed; and an optical unit for providing light energy to the photoconductive layer to detrap a charge trapped in an interface between the photoconductive particle and the binder. The light energy includes ultraviolet rays and/or visible rays.
    Type: Application
    Filed: August 6, 2015
    Publication date: February 11, 2016
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Dongwook LEE, Kangho LEE
  • Patent number: 9245610
    Abstract: A one time programming (OTP) apparatus unit cell includes magnetic tunnel junctions (MTJs) with reversed connections for placing the MTJ in an anti-parallel resistance state during programming. Increased MTJ resistance in its anti-parallel resistance state causes a higher programming voltage which reduces programming time and programming current.
    Type: Grant
    Filed: September 13, 2012
    Date of Patent: January 26, 2016
    Assignee: QUALCOMM Incorporated
    Inventors: Jung Pill Kim, Taehyun Kim, Kangho Lee, Seung H. Kang, Xia Li, Wah Nam Hsu
  • Patent number: 9245608
    Abstract: Perpendicular magnetic anisotropy (PMA) type magnetic random access memory cells are constructed with a composite PMA layer to provide a magnetic tunnel junction (MTJ) with an acceptable thermal barrier. A PMA coupling layer is deposited between a first PMA layer and a second PMA layer to form the composite PMA layer. The composite PMA layer may be incorporated in PMA type MRAM cells or in-plane type MRAM cells.
    Type: Grant
    Filed: August 10, 2012
    Date of Patent: January 26, 2016
    Assignee: QUALCOMM Incorporated
    Inventors: Wei-Chuan Chen, Kangho Lee, Xiaochun Zhu, Seung H. Kang
  • Publication number: 20160020250
    Abstract: An MRAM cell may include a magnetic tunneling junction (MTJ). The MTJ includes a pin layer, a barrier layer, a free layer, and a capping layer. The MRAM cell further includes a bidirectional diode selector, directly coupled to an electrode of the MTJ, to enable access to the MTJ.
    Type: Application
    Filed: July 17, 2014
    Publication date: January 21, 2016
    Inventors: Xia LI, Wei-Chuan CHEN, Yu LU, Kangho LEE, Seung Hyuk KANG
  • Publication number: 20160020383
    Abstract: A method for integrating a magnetic tunnel junction (MTJ) device into an integrated circuit includes providing in a semiconductor back-end-of-line (BEOL) process flow a substrate having a first interlevel dielectric layer and at least a first conductive interconnect. Over the first interlevel dielectric layer and the first conductive interconnect, magnetic tunnel junction material layers are deposited. From the material layers a magnetic tunnel junction stack, coupled to the first conductive interconnect, is defined using a single mask process. The magnetic tunnel junction stack is integrated into the integrated circuit.
    Type: Application
    Filed: September 30, 2015
    Publication date: January 21, 2016
    Inventors: Seung H. KANG, David BANG, Kangho LEE
  • Publication number: 20160005955
    Abstract: A magnetic tunnel junction (MTJ) device in a magnetoresistive random access memory (MRAM) and method of making the same are provided to achieve a high tunneling magnetoresistance (TMR), a high perpendicular magnetic anisotropy (PMA), good data retention, and a high level of thermal stability. The MTJ device includes a first free ferromagnetic layer, a synthetic antiferromagnetic (SAF) coupling layer, and a second free ferromagnetic layer, where the first and second free ferromagnetic layers have opposite magnetic moments.
    Type: Application
    Filed: July 1, 2014
    Publication date: January 7, 2016
    Inventors: Chando PARK, Matthias Georg GOTTWALD, Kangho LEE, Seung Hyuk KANG
  • Patent number: 9230630
    Abstract: One feature pertains to a method for implementing a physically unclonable function (PUF). The method includes providing an array of magnetoresistive random access memory (MRAM) cells, where the MRAM cells are each configured to represent one of a first logical state and a second logical state. The array of MRAM cells are un-annealed and free from exposure to an external magnetic field oriented in a direction configured to initialize the MRAM cells to a single logical state of the first and second logical states. Consequently, each MRAM cell has a random initial logical state of the first and second logical states. The method further includes sending a challenge to the MRAM cell array that reads logical states of select MRAM cells of the array, and obtaining a response to the challenge from the MRAM cell array that includes the logical states of the selected MRAM cells of the array.
    Type: Grant
    Filed: November 5, 2013
    Date of Patent: January 5, 2016
    Assignee: QUALCOMM Incorporated
    Inventors: Xiaochun Zhu, Steven M. Millendorf, Xu Guo, David M. Jacobson, Kangho Lee, Seung H. Kang, Matthew Michael Nowak
  • Patent number: 9224467
    Abstract: A resistance-based memory includes a two-diode access device. In a particular embodiment, a method includes biasing a bit line with a first voltage. The method further includes biasing the sense line with a second voltage. Biasing the bit line and biasing the sense line generates a current through a resistance-based memory element and through one of a first diode and a second diode. A cathode of the first diode is coupled to the bit line and an anode of the second diode is coupled to the sense line.
    Type: Grant
    Filed: January 6, 2014
    Date of Patent: December 29, 2015
    Assignee: QUALCOMM Incorporated
    Inventors: Wuyang Hao, Jungwon Suh, Kangho Lee, Taehyun Kim, Jung Pill Kim, Seung Hyuk Kang
  • Patent number: 9214624
    Abstract: A perpendicular magnetic tunnel junction (MTJ) apparatus includes a tunnel magnetoresistance (TMR) enhancement buffer layer deposited between the tunnel barrier layer and the reference layers An amorphous alloy spacer is deposited between the TMR enhancement buffer layer and the reference layers to enhance TMR The amorphous alloy spacer blocks template effects of face centered cubic (fcc) oriented pinned layers and provides strong coupling between the pinned layers and the TMR enhancement buffer layer to ensure full perpendicular magnetization.
    Type: Grant
    Filed: February 19, 2013
    Date of Patent: December 15, 2015
    Assignee: QUALCOMM Incorporated
    Inventors: Kangho Lee, Wei-Chuan Chen, Seung H. Kang
  • Patent number: 9214214
    Abstract: One feature pertains to a method of implementing a physically unclonable function (PUF). The method includes exposing an array of magnetoresistive random access memory (MRAM) cells to an orthogonal external magnetic field. The MRAM cells are each configured to represent one of a first logical state and a second logical state, and the orthogonal external magnetic field is oriented in an orthogonal direction to an easy axis of a free layer of the MRAM cells to place the MRAM cells in a neutral logical state that is not the first logical state or the second logical state. The method further includes removing the orthogonal external magnetic field to place each of the MRAM cells of the array randomly in either the first logical state or the second logical state.
    Type: Grant
    Filed: November 5, 2013
    Date of Patent: December 15, 2015
    Assignee: QUALCOMM Incorporated
    Inventors: Xiaochun Zhu, Steven M. Millendorf, Xu Guo, David M. Jacobson, Kangho Lee, Seung H. Kang, Matthew Michael Nowak
  • Publication number: 20150349244
    Abstract: A memory cell includes a magnetic tunnel junction (MTJ) structure that includes a free layer coupled to a bit line and a pinned layer. A magnetic moment of the free layer is substantially parallel to a magnetic moment of the pinned layer in a first state and substantially antiparallel to the magnetic moment of the pinned layer in a second state. The pinned layer has a physical dimension to produce an offset magnetic field corresponding to a first switching current of the MTJ structure to enable switching between the first state and the second state when a first voltage is applied from the bit line to a source line coupled to an access transistor and a second switching current to enable switching between the second state and the first state when the first voltage is applied from the source line to the bit line.
    Type: Application
    Filed: August 10, 2015
    Publication date: December 3, 2015
    Inventors: Kangho Lee, Seung Kang, Xiaochun Zhu
  • Publication number: 20150326802
    Abstract: Provided are methods of detecting X-rays, a photographing methods using the X-ray detecting method and/or an X-ray detector using the methods. For example, one method of detecting X-rays includes radiating a first X-ray, removing, by a first X-ray detection unit, a first electric charge generated by the radiated first X-ray, and outputting, by a second X-ray detection unit adjacent to the first X-ray detection unit, a voltage corresponding to the first X-ray.
    Type: Application
    Filed: April 13, 2015
    Publication date: November 12, 2015
    Inventors: Young KIM, Yongchul Kim, Jaechul Park, Kangho Lee
  • Publication number: 20150311429
    Abstract: An improved magnetic tunnel junction device and methods for fabricating the improved magnetic tunnel junction device are provided. The provided two-etch process reduces etching damage and ablated material redeposition. In an example, provided is a method for fabricating a magnetic tunnel junction (MTJ). The method includes forming a buffer layer on a substrate, forming a bottom electrode on the substrate, forming a pin layer on the bottom electrode, forming a barrier layer on the pin layer, and forming a free layer on the barrier layer. A first etching includes etching the free layer, without etching the barrier layer, the pin layer, and the bottom electrode. The method also includes forming a top electrode on the free layer, as well as forming a hardmask layer on the top electrode. A second etching includes etching the hardmask layer; the top electrode layer, the barrier layer, the pin layer, and the bottom electrode.
    Type: Application
    Filed: July 9, 2015
    Publication date: October 29, 2015
    Inventors: Xia LI, Kangho LEE, Wei-Chuan CHEN, Yu LU, Chando PARK, Seung Hyuk KANG