Patents by Inventor Seung H. Kang

Seung H. Kang 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: 8802452
    Abstract: In a particular embodiment, a method of forming a magnetic tunnel junction (MTJ) device includes forming an MTJ cap layer on an MTJ structure and forming a top electrode layer coupled to the MTJ cap layer. The top electrode layer includes at least two layers and one layer of the two layers includes a nitrified metal.
    Type: Grant
    Filed: June 25, 2013
    Date of Patent: August 12, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Xia Li, Seung H. Kang
  • Publication number: 20140219015
    Abstract: A method includes creating a breakdown condition at a semiconductor transistor structure that includes an overlap region and a channel region. The breakdown condition is created by causing a first voltage difference between a gate of the semiconductor transistor structure and the overlap region to exceed a breakdown voltage of the semiconductor transistor structure while maintaining a second voltage difference between the gate and the channel region at less than the breakdown voltage.
    Type: Application
    Filed: February 5, 2013
    Publication date: August 7, 2014
    Applicant: QUALCOMM INCORPORATED
    Inventors: Xia Li, Seung H. Kang, Xiaochun Zhu
  • Publication number: 20140222880
    Abstract: A method and apparatus for generating random binary sequences from a physical entropy source having a state A and a state B by detecting whether the physical entropy source is in the state A or in the state B, attempting to shift the state of the physical entropy source to the opposite state in a probabilistic manner with less than 100% certainty, and producing one of four outputs based on the detected state and the state of the physical entropy source before the attempted shift. The outputs are placed in first and second queues and extracted in pairs from each queue. Random binary bits are output based on the sequences extracted from each queue.
    Type: Application
    Filed: February 5, 2013
    Publication date: August 7, 2014
    Applicant: QUALCOMM INCORPORATED
    Inventors: Wenqing Wu, Peiyuan Wang, Raghu Sagar Madala, Senthil Kumar Govindaswamy, Kendrick H. Yuen, Robert P. Gilmore, Jung Pill Kim, Seung H. Kang
  • Patent number: 8797792
    Abstract: A memory device includes a magnetic tunnel junction (MTJ) bitcell. The MTJ bitcell includes a first MTJ and a second MTJ. The memory device further includes programming circuitry configured to generate a non-reversible state at the bitcell by applying a program signal to a selected one of the first MTJ and the second MTJ of the bitcell. The non-reversible state corresponds to a value of the MTJ bitcell that is determined by comparing a first value read at the first MTJ and a second value read at the second MTJ.
    Type: Grant
    Filed: September 10, 2013
    Date of Patent: August 5, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Hari M. Rao, Jung Pil Kim, Seung H. Kang, Xiaochun Zhu, Tae Hyun Kim, Kangho Lee, Xia Li, Wah Nam Hsu, Wuyang Hao, Jungwon Suh, Nicholas K. Yu, Matthew Michael Nowak, Steven M. Millendorf, Asaf Ashkenazi
  • Publication number: 20140211551
    Abstract: Memory self-repair circuitry includes a memory cell array on a chip, and built-in self test (BIST) circuitry on the chip coupled to the memory cell array. The BIST circuitry is configured to perform a magnetic random access memory (MRAM) write operation to write addresses of failed memory cells in the memory cell array to a failed address sector also in the memory cell array. The memory self-repair circuitry also includes first select circuitry coupled between the BIST circuitry and the memory cell array. The first select circuitry is configured to selectively couple an output of the BIST circuitry and an input to the memory cell array.
    Type: Application
    Filed: January 31, 2013
    Publication date: July 31, 2014
    Applicant: QUALCOMM INCORPORATED
    Inventors: Jung Pill Kim, Taehyun Kim, Xia Li, Seung H. Kang
  • Publication number: 20140210021
    Abstract: An in-process magnetic layer having an in-process area dimension is formed with a chemically damaged region at a periphery. At least a portion of the chemically damaged region is transformed to a chemically modified peripheral portion that is non-ferromagnetic. Optionally, the transforming is by oxidation, nitridation or fluorination, or combinations of the same.
    Type: Application
    Filed: January 25, 2013
    Publication date: July 31, 2014
    Applicant: QUALCOMM INCORPORATED
    Inventors: Xiaochun Zhu, Xia Li, Seung H. Kang
  • Publication number: 20140203381
    Abstract: Material surrounding a magnetic tunnel junction (MTJ) device region of a multi-layer starting structure is etched, forming an MTJ device pillar having an MTJ layer with a chemically damaged peripheral edge region. De-nitridation or de-oxidation, or both, restore the chemically damaged peripheral region to form an edge-restored MTJ layer. An MTJ edge restoration assist layer is formed on the edge-restored MTJ layer. An MTJ-edge-protect layer is formed on the insulating MTJ-edge-restoration-assist layer.
    Type: Application
    Filed: January 24, 2013
    Publication date: July 24, 2014
    Applicant: QUALCOMM INCORPORATED
    Inventors: Xiaochun Zhu, Xia Li, Wei-Chuan Chen, Seung H. Kang
  • Patent number: 8735179
    Abstract: A magnetic tunnel junction (MTJ) device and fabrication method is disclosed. In a particular embodiment, a method of forming a magnetic tunnel junction (MTJ) device includes forming a top electrode layer over an MTJ structure. The top electrode layer includes a first nitrified metal.
    Type: Grant
    Filed: September 11, 2009
    Date of Patent: May 27, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Xia Li, Seung H. Kang
  • Publication number: 20140139209
    Abstract: Several novel features pertain to an automatic testing equipment (ATE) memory tester that includes a load board, a projected-field electromagnet, a positioning mechanism and a memory tester. The load board is for coupling to a die package that includes a magnetoresistive random access memory (MRAM) having several cells, where each cell includes a magnetic tunnel junction (MTJ). The projected-field electromagnet is for applying a portion of a magnetic field across the MRAM. The portion of the magnetic field may be substantially uniform. The positioning mechanism is coupled to the electromagnet and the load board, and is configured to position the electromagnet vertically about (above/below) the die package when the die package is coupled to the load board. The memory tester is coupled to the load board. The memory tester is for testing the MRAM when the substantially uniform portion of the magnetic field is applied across the MRAM.
    Type: Application
    Filed: November 19, 2012
    Publication date: May 22, 2014
    Applicant: QUALCOMM INCORPORATED
    Inventors: Kangho Lee, Xiao Lu, Wah Nam Hsu, Seung H. Kang
  • Patent number: 8719610
    Abstract: A computing system includes at least one functional unit and a magnetic random access memory (MRAM) block coupled to the at least one functional unit. The MRAM block is configured to store a functional state of the at least one functional unit during a power down state of the at least one functional unit.
    Type: Grant
    Filed: September 23, 2008
    Date of Patent: May 6, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Matthew Michael Nowak, Lew Chua-Eoan, Seung H Kang
  • Patent number: 8717811
    Abstract: A non-volatile latch circuit includes a pair of cross-coupled inverters, a pair of resistance-based memory elements, and write circuitry configured to write data to the pair of resistance-based memory elements. The pair of resistance-based memory elements is isolated from the pair of cross-coupled inverters during a latching operation. A sensing circuit includes a first current path that includes a resistance-based memory element and an output of the sensing circuit. The sensing circuit includes a second current path to reduce current flow through the resistance-based memory element at a first operating point of the sensing circuit.
    Type: Grant
    Filed: March 5, 2013
    Date of Patent: May 6, 2014
    Assignees: QUALCOMM Incorporated, Industry-Academic Cooperation Foundation, Yonsei University
    Inventors: Seong-Ook Jung, Kyungho Ryu, Jisu Kim, Jung Pill Kim, Seung H. Kang
  • Patent number: 8704320
    Abstract: Partial perpendicular magnetic anisotropy (PPMA) type magnetic random access memory cells are constructed using processes and structural configurations that induce a directed static strain/stress on an MTJ to increase the perpendicular magnetic anisotropy. Consequently, reduced switching current of the MTJ results. The directed static strain/stress on the MTJ is induced in a controlled direction and/or with a controlled magnitude during fabrication. The MTJ is permanently subject to a predetermined directed stress and permanently includes the directed static strain/strain that provides reduced switching current.
    Type: Grant
    Filed: January 26, 2012
    Date of Patent: April 22, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Xiaochun Zhu, Xia Li, Wei-Chuan Chen, Seung H. Kang
  • Publication number: 20140108478
    Abstract: A random number generator system that utilizes a magnetic tunnel junction (MTJ) that is controlled by an STT-MTJ entropy controller that determines whether to proceed with generating random numbers or not by monitoring the health of the MTJ-based random number generator is illustrated. If the health of the random number generation is above a threshold, the STT-MTJ entropy controller shuts down the MTJ-based random number generator and sends a message to a requesting chipset that a secure key generation is not possible. If the health of the random number generation is below a threshold, the entropy controller allows the MTJ-based random number generator to generate random numbers based on a specified algorithm, the output of which is post processed and used by a cryptographic-quality deterministic random bit generator to generate a security key for a requesting chipset.
    Type: Application
    Filed: October 15, 2012
    Publication date: April 17, 2014
    Applicant: QUALCOMM INCORPORATED
    Inventors: Kangho Lee, Taehyun Kim, Xiaochun Zhu, David M. Jacobson, Raghu Sagar Madala, Wenqing Wu, Jung Pill Kim, Seung H. Kang
  • Patent number: 8693272
    Abstract: A circuit includes a degeneration p-channel metal-oxide-semiconductor (PMOS) transistor, a load PMOS transistor, and a clamp transistor configured to clamp a voltage applied to a resistance based memory element during a sensing operation. A gate of the load PMOS transistor is controlled by an output of an operational amplifier.
    Type: Grant
    Filed: June 30, 2011
    Date of Patent: April 8, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Seong-Ook Jung, Jisu Kim, Kyungho Ryu, Seung H. Kang
  • Patent number: 8681536
    Abstract: A magnetic tunnel junction (MTJ) with direct contact is manufactured having lower resistances, improved yield, and simpler fabrication. The lower resistances improve both read and write processes in the MTJ. The MTJ layers are deposited on a bottom electrode aligned with the bottom metal. An etch stop layer may be deposited adjacent to the bottom metal to prevent overetch of an insulator surrounding the bottom metal. The bottom electrode is planarized before deposition of the MTJ layers to provide a substantially flat surface. Additionally, an underlayer may be deposited on the bottom electrode before the MTJ layers to promote desired characteristics of the MTJ.
    Type: Grant
    Filed: May 11, 2010
    Date of Patent: March 25, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Seung H. Kang, Xia Li, Wei-Chuan Chen, Kangho Lee, Xiaochun Zhu, Wah Nam Hsu
  • Patent number: 8674465
    Abstract: A semiconductor device includes a magnetic tunnel junction (MTJ) storage element configured to be disposed in a common interlayer metal dielectric (IMD) layer with a logic element. Cap layers separate the common IMD layer from a top and bottom IMD layer. Top and bottom electrodes are coupled to the MTJ storage element. Metal connections to the electrodes are formed in the top and bottom IMD layers respectively through vias in the separating cap layers. Alternatively, the separating cap layers are recessed and the bottom electrodes are embedded, such that direct contact to metal connections in the bottom IMD layer is established. Metal connections to the top electrode in the common IMD layer are enabled by isolating the metal connections from the MTJ storage elements with metal islands and isolating caps.
    Type: Grant
    Filed: August 5, 2010
    Date of Patent: March 18, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Xia Li, Xiaochun Zhu, Seung H. Kang
  • Publication number: 20140071741
    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: Application
    Filed: September 13, 2012
    Publication date: March 13, 2014
    Applicant: QUALCOMM Incorporated
    Inventors: Jung Pill Kim, Taehyun Kim, Kangho Lee, Seung H. Kang, Xia Li, Wah Nam Hsu
  • Patent number: 8670266
    Abstract: A flip-flop has an output control node and an isolation switch selectively couples a retention sense node to the output control node. A sense circuit selectively couples an external sense current source to the retention sense node and to magnetic tunneling junction (MTJ) elements. Optionally a write circuit selectively injects a write current through one MTJ element and then another MTJ element. Optionally, a write circuit injects a write current through a first MTJ element concurrently with injecting a write current through a second MTJ element.
    Type: Grant
    Filed: January 30, 2012
    Date of Patent: March 11, 2014
    Assignees: QUALCOMM Incorporated, Industry-Academic Cooperation Foundation, Yonsei University
    Inventors: Seong-Ook Jung, Kyungho Ryu, Youngdon Jung, Jisu Kim, Jung Pill Kim, Seung H. Kang
  • Publication number: 20140063922
    Abstract: Systems, circuits and methods for controlling word line (WL) power levels at a WL of a Magnetoresistive Random Access Memory (MRAM). The disclosed power control scheme uses existing read/write commands and an existing power generation module associated, with the MRAM to supply and control WL power levels, thereby eliminating the cost and increased die-size of schemes that control WL power through relatively large and expensive power control switches and control circuitry on the MRAM macro.
    Type: Application
    Filed: September 4, 2012
    Publication date: March 6, 2014
    Applicant: QUALCOMM Incorporated
    Inventors: Sungryul Kim, Jung Pill Kim, Taehyun Kim, Seung H. Kang, Matthew M. Nowak, Manoj Bhatnagar
  • Publication number: 20140067890
    Abstract: Embodiments of the disclosure are directed to generating a random number. An embodiment of the disclosure passes a current from a read operation through a magnetic tunnel junction (MTJ) to cause a first magnetization orientation of a free layer to switch to a second magnetization orientation, the switch in magnetization orientation causing a change in a resistance of the MTJ, and periodically samples the resistance of the MTJ to generate a bit value for the random number.
    Type: Application
    Filed: September 4, 2012
    Publication date: March 6, 2014
    Applicant: QUALCOMM Incorporated
    Inventors: Xiaochun Zhu, Wenqing Wu, David M. Jacobson, Seung H. Kang, Kendrick H. Yuen