Patents by Inventor Hongyu Liu

Hongyu Liu 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: 7944742
    Abstract: A memory array includes a cross-point array of bit and source lines. A memory is disposed at cross-points of the cross-point array. The memory unit includes a magnetic tunnel junction data cell electrically coupled to a bit line and a source line. The magnetic tunnel junction data cell is configured to switch between a high resistance state and a low resistance state by passing a polarized write current through the magnetic tunnel junction data cell. A transistor is electrically between the magnetic tunnel junction data cell and the bit line or source line and a diode is in thermal or electrical contact with the magnetic tunnel junction data cell to assist in resistance state switching.
    Type: Grant
    Filed: August 24, 2010
    Date of Patent: May 17, 2011
    Assignee: Seagate Technology LLC
    Inventors: Xuguang Wang, Yiran Chen, Dimitar V. Dimitrov, Hongyue Liu, Xiaobin Wang
  • Patent number: 7944729
    Abstract: Method and apparatus are disclosed for storing data to non-volatile resistive sense memory (RSM) memory cells of a semiconductor memory array, including but not limited to resistive random access memory (RRAM) and spin-torque transfer random access memory (STTRAM or STRAM) cells. In accordance with various embodiments, a plurality of addressable data blocks from a host device are stored in a buffer. At least a portion of each of the addressable data blocks are serially transferred to a separate register of a plurality of registers. The transferred portions of said addressable data blocks are thereafter simultaneously transferred from the registers to selected RSM cells of the array.
    Type: Grant
    Filed: January 28, 2009
    Date of Patent: May 17, 2011
    Assignee: Seagate Technology LLC
    Inventors: Yiran Chen, Daniel S. Reed, Yong Lu, Harry Hongyue Liu, Hai Li, Rod V. Bowman
  • Patent number: 7940548
    Abstract: A resistive sense memory apparatus includes a first semiconductor transistor having a first contact electrically connected to a first source line and a second contact electrically connected to a first resistive sense memory element and a second semiconductor transistor having a first contact electrically connected to a second source line and a second contact electrically connected to a second resistive sense memory element. A bit line is electrically connected to the first resistive sense memory element and the second resistive sense memory element.
    Type: Grant
    Filed: July 13, 2009
    Date of Patent: May 10, 2011
    Assignee: Seagate Technology LLC
    Inventors: Xuguang Wang, Hai Li, Hongyue Liu
  • Patent number: 7936583
    Abstract: Variable resistive punchthrough access methods are described. The methods include switching a variable resistive data cell from a high resistance state to a low resistance state by passing a write current through the magnetic tunnel junction data cell in a first direction. The write current is provided by a transistor being electrically coupled to the variable resistive data cell and a source line. The write current passes through the transistor in punchthrough mode.
    Type: Grant
    Filed: October 30, 2008
    Date of Patent: May 3, 2011
    Assignee: Seagate Technology LLC
    Inventors: Maroun Georges Khoury, Hongyue Liu, Brian Lee, Andrew John Gjevre Carter
  • Patent number: 7936622
    Abstract: Various embodiments of the present invention are generally directed to an apparatus and associated method for handling defective bits in a multi-layer integrated memory device. In accordance with some embodiments, the multi-layer integrated memory device is formed from a plurality of vertically stacked semiconductor layers each having a number of storage sub-arrays and redundant sub-arrays. Each semiconductor layer is tested to determine a defect rate for each array, and a defective portion of a first semiconductor layer having a relatively higher defect rate is stored to a redundant sub-array of a second semiconductor layer having a relatively lower defect rate.
    Type: Grant
    Filed: July 13, 2009
    Date of Patent: May 3, 2011
    Assignee: Seagate Technology LLC
    Inventors: Hai Li, Yiran Chen, Dadi Setiadi, Harry Hongyue Liu, Brian Lee
  • Patent number: 7936588
    Abstract: The present disclosure relates to memory arrays with read reference voltage cells. In particular the present disclosure relates to variable resistive memory cell apparatus and arrays that include a high resistance state reference memory cell and a low resistance state reference memory cell that provides a reliable average reference voltage on chip to compare to a read voltage of a selected memory cell and determine if the selected memory cell is in the high resistance state or low resistance state. These memory arrays are particularly suitable for use with spin-transfer torque memory cells and resolves many systematic issues related to generation of a reliable reference voltage.
    Type: Grant
    Filed: May 28, 2010
    Date of Patent: May 3, 2011
    Assignee: Seagate Technology LLC
    Inventors: Hongyue Liu, Yong Lu, Andrew Carter, Yiran Chen, Hai Li
  • Patent number: 7936592
    Abstract: A method and apparatus for writing data to a non-volatile memory cell, such as a spin-torque transfer random access memory (STRAM) memory cell. In some embodiments, a selected resistive state is written to a magnetic tunneling structure by applying a succession of indeterminate write pulses thereto until the selected resistive state is verified.
    Type: Grant
    Filed: February 3, 2009
    Date of Patent: May 3, 2011
    Assignee: Seagate Technology LLC
    Inventors: Xiaobin Wang, Yong Lu, Haiwen Xi, Yuankai Zheng, Yiran Chen, Harry Hongyue Liu, Dimitar Dimitrov, Wei Tan, Brian Seungwhan Lee
  • Patent number: 7936580
    Abstract: A memory unit includes a magnetic tunnel junction data cell is electrically coupled to a bit line and a source line. The magnetic tunnel junction data cell is configured to switch between a high resistance state and a low resistance state by passing a write current through the magnetic tunnel junction data cell. A first diode is electrically between the magnetic tunnel junction data cell and the source line and a second diode is electrically between the magnetic tunnel junction data cell and the source line. The first diode and second diode are in parallel electrical connection, and having opposing forward bias directions.
    Type: Grant
    Filed: October 20, 2008
    Date of Patent: May 3, 2011
    Assignee: Seagate Technology LLC
    Inventors: Yiran Chen, Hai Li, Hongyue Liu, Yong Lu, Song S. Xue
  • Patent number: 7936625
    Abstract: Various embodiments are generally directed to a method and apparatus for carrying out a pipeline sensing operation. In some embodiments, a read voltage from a first memory cell is stored in a voltage storage element (VSE) and compared to a reference voltage to identify a corresponding memory state of the first memory cell while a second read voltage from a second memory cell is stored in a second VSE. In other embodiments, bias currents are simultaneously applied to a first set of memory cells from the array while read voltages generated thereby are stored in a corresponding first set of VSEs. The read voltages are sequentially compared with at least one reference value to serially output a logical sequence corresponding to the memory states of the first set of memory cells while read voltages are stored for a second set of memory cells in a second set of VSEs.
    Type: Grant
    Filed: March 24, 2009
    Date of Patent: May 3, 2011
    Assignee: Seagate Technology LLC
    Inventors: Yiran Chen, Hai Li, Harry Hongyue Liu, KangYong Kim, Henry F. Huang
  • Publication number: 20110089509
    Abstract: Magnetic memory having separate read and write paths is disclosed. The magnetic memory unit includes a ferromagnetic strip having a first end portion with a first magnetization orientation, an opposing second end portion with a second magnetization orientation, and a middle portion between the first end portion and the second end portion, the middle portion having a free magnetization orientation. The first magnetization orientation opposes the second magnetization orientation. A tunneling barrier separates a magnetic reference layer from the middle portion forming a magnetic tunnel junction. A bit line is electrically coupled to the second end portion. A source line is electrically coupled to the first end portion and a read line is electrically coupled to the magnetic tunnel junction.
    Type: Application
    Filed: December 21, 2010
    Publication date: April 21, 2011
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Yong Lu, Hongyue Liu, Zheng Gao, Insik Jin, Dimitar V. Dimitrov
  • Publication number: 20110090733
    Abstract: A memory unit includes a giant magnetoresistance cell electrically coupled between a write bit line and a write source line. The giant magnetoresistance cell includes a free magnetic layer separated from a first pinned magnetic layer by a first non-magnetic electrically conducting layer. A magnetic tunnel junction data cell is electrically coupled between a read bit line and a read source line. The magnetic tunnel junction data cell includes the free magnetic layer separated from a second pinned magnetic layer by an oxide barrier layer. A write current passes through the giant magnetoresistance cell to switche the giant magnetoresistance cell between a high resistance state and a low resistance state. The magnetic tunnel junction data cell is configured to switch between a high resistance state and a low resistance state by magnetostatic coupling with the giant magnetoresistance cell, and be read by a read current passing though the magnetic tunnel junction data cell.
    Type: Application
    Filed: December 21, 2010
    Publication date: April 21, 2011
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Haiwen Xi, Hongyue Liu, Michael Xuefei Tang, Antoine Khoueir, Song S. Xue
  • Publication number: 20110080782
    Abstract: Apparatus and method for write current compensation in a non-volatile memory cell, such as but not limited to spin-torque transfer random access memory (STRAM) or resistive random access memory (RRAM). In accordance with some embodiments, a non-volatile memory cell has a resistive sense element (RSE) coupled to a switching device, the RSE having a hard programming direction and an easy programming direction opposite the hard programming direction. A voltage boosting circuit includes a capacitor which adds charge to a nominal non-zero voltage supplied by a voltage source to a node to generate a temporarily boosted voltage. The boosted voltage is applied to the switching device when the RSE is programmed in the hard programming direction.
    Type: Application
    Filed: December 14, 2010
    Publication date: April 7, 2011
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Hai Li, Yiran Chen, Harry Hongyue Liu, Henry Huang, Ran Wang
  • Publication number: 20110080769
    Abstract: The present disclosure relates to methods of selectively placing a reference column or reference row in a memory array. The method includes measuring a resistance state resistance value for a plurality of variable resistive memory cells within a memory array and mapping a location of each measured variable resistive memory cell to form a map of the resistance state resistance values for a plurality of variable resistive memory cells within a memory array. Then a column or row is selected to be a reference column or reference row based on the map of the resistance state resistance value for a plurality of variable resistive memory cells within a memory array, to minimize read operation errors, and forming a variable resistive memory cell memory array.
    Type: Application
    Filed: December 15, 2010
    Publication date: April 7, 2011
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Yiran Chen, Hai Li, Wenzhong Zhu, Xiaobin Wang, Henry Huang, Hongyue Liu
  • Publication number: 20110080768
    Abstract: Apparatus and method for write current compensation in a non-volatile memory cell, such as but not limited to spin-torque transfer random access memory (STRAM) or resistive random access memory (RRAM). In accordance with some embodiments, a non-volatile memory cell has a resistive sense element (RSE) coupled to a switching device, the RSE having a hard programming direction and an easy programming direction opposite the hard programming direction. A voltage boosting circuit includes a capacitor which adds charge to a nominal non-zero voltage supplied by a voltage source to a node to generate a temporarily boosted voltage. The boosted voltage is applied to the switching device when the RSE is programmed in the hard programming direction.
    Type: Application
    Filed: December 14, 2010
    Publication date: April 7, 2011
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Hai Li, Yiran Chen, Harry Hongyue Liu, Henry Huang, Ran Wang
  • Patent number: 7916515
    Abstract: An apparatus and associated method for writing data to a non-volatile memory cell, such as a resistive random access memory (RRAM) cell. In some embodiments, a control circuitry is configured to write a logic state to a resistive sense element while simultaneously verifying the logic state of the resistive sense element.
    Type: Grant
    Filed: March 10, 2009
    Date of Patent: March 29, 2011
    Assignee: Seagate Technology LLC
    Inventors: Hai Li, Yiran Chen, Harry Hongyue Liu, Alan Xuguang Wang
  • Patent number: 7916528
    Abstract: A method and apparatus for using thermal preconditioning to write data to a non-volatile memory cell, such as a spin-torque transfer random access memory (STRAM) memory cell. In some embodiments, a logical state is written to an unconditioned non-volatile first memory cell associated with a first block address. Thermal preconditioning is concurrently applied to a non-volatile second memory cell associated with a second block address selected in response to the first block address.
    Type: Grant
    Filed: March 30, 2009
    Date of Patent: March 29, 2011
    Assignee: Seagate Technology LLC
    Inventors: Yiran Chen, Hai Li, Harry Hongyue Liu, Dimitar V. Dimitrov, Alan Xuguang Wang, Xiaobin Wang
  • Publication number: 20110063901
    Abstract: A memory array includes a plurality of magnetic tunnel junction cells arranged in a 2 by 2 array. Each magnetic tunnel junction cell is electrically coupled between a bit line and a source line and each magnetic tunnel junction cell electrically coupled to a transistor. Each magnetic tunnel junction cell is configured to switch between a high resistance state and a low resistance state by passing a write current passing though the magnetic tunnel junction cell. A first word line is electrically coupled to a gate of first set of two of the transistors and a second word line is electrically coupled to a gate of a second set of two of the transistors. The source line is a common source line for the plurality of magnetic tunnel junctions.
    Type: Application
    Filed: November 18, 2010
    Publication date: March 17, 2011
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Hai Li, Yiran Chen, Hongyue Liu, Xuguang Wang
  • Publication number: 20110058409
    Abstract: A memory unit includes a magnetic tunnel junction data cell is electrically coupled to a bit line and a source line. The magnetic tunnel junction data cell is configured to switch between a high resistance state and a low resistance state by passing a write current through the magnetic tunnel junction data cell. A first diode is electrically between the magnetic tunnel junction data cell and the source line and a second diode is electrically between the magnetic tunnel junction data cell and the source line. The first diode and second diode are in parallel electrical connection, and having opposing forward bias directions. The memory unit is configured to be precharged to a specified precharge voltage level and the precharge voltage is less than a threshold voltage of the first diode and second diode.
    Type: Application
    Filed: November 18, 2010
    Publication date: March 10, 2011
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Yiran Chen, Hai Li, Hongyue Liu, Yong Lu, Song S. Xue
  • Publication number: 20110058404
    Abstract: Variable resistive punchthrough access methods are described. The methods include switching a variable resistive data cell from a high resistance state to a low resistance state by passing a write current through the magnetic tunnel junction data cell in a first direction. The write current is provided by a transistor being electrically coupled to the variable resistive data cell and a source line. The write current passes through the transistor in punchthrough mode.
    Type: Application
    Filed: November 12, 2010
    Publication date: March 10, 2011
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Maroun Georges Khoury, Hongyue Liu, Brian Lee, Andrew John Gjevre Carter
  • Publication number: 20110058405
    Abstract: Various embodiments of the present invention are generally directed to a method and apparatus for sensing a programmed state of a memory cell, such as a spin-torque transfer random access memory (STRAM) cell. A first read current is applied to the memory cell to generate a first voltage. A second read current is subsequently applied to the memory cell to generate a second voltage, with the second read current being proportional in magnitude to the first read current. A comparison is made between the first and second voltages to determine the programmed state of the memory cell.
    Type: Application
    Filed: November 15, 2010
    Publication date: March 10, 2011
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Yiran Chen, Hai Li, Wenzhong Zhu, Xiaobin Wang, Ran Wang, Harry Hongyue Liu