Patents by Inventor Yiran Chen

Yiran Chen 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: 20110122679
    Abstract: Resistive memory calibration for self-reference read methods are described. One method of self-reference reading a resistive memory unit includes setting a plurality of resistive memory units to a first resistive data state. The resistive memory units forms a memory array. Reading a sensed resistive data state for each resistive memory unit by applying a first read current and a second read current through each resistive memory unit and then comparing voltages formed by the first read current and the second read current to determine the sensed resistive data state for each resistive memory unit. Then the method includes adjusting the first or the second read current, read voltages, or storage device capacitance for each resistive memory unit where the sensed resistive data state was not the same as the first resistive data state until the sensed resistive data state is the same as the first resistive data state.
    Type: Application
    Filed: January 27, 2011
    Publication date: May 26, 2011
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Yiran Chen, Hai Li, Wenzhong Zhu, Xiaobin Wang, Henry Huang, Hongyue Liu
  • Publication number: 20110116303
    Abstract: A magnetic memory device includes a magnetic tunnel junction having a free magnetic layer having a magnetization orientation that is switchable between a high resistance state magnetization orientation and a low resistance state magnetization orientation and a memristor solid state element electrically coupled to the magnetic tunnel junction. The memristor has a device response that is an integrated voltage versus an integrated current.
    Type: Application
    Filed: January 24, 2011
    Publication date: May 19, 2011
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Xiaobin Wang, Yiran Chen, Alan Wang, Haiwen Xi, Wenzhong Zhu, Hai Li, Hongyue Liu
  • Patent number: 7944731
    Abstract: Various embodiments of the present invention are generally directed to a method and apparatus for carrying out a partial block update operation upon a resistive sense memory (RSM) array, such as formed from STRAM or RRAM cells. The RSM array is arranged into multi-cell blocks (sectors), each block having a physical block address (PBA). A first set of user data is written to a selected block at a first PBA. A partial block update operation is performed by writing a second set of user data to a second block at a second PBA, the second set of user data updating a portion of the first set of user data in the first PBA. The first and second blocks are thereafter read to retrieve the second set of user data and a remaining portion of the first set of user data.
    Type: Grant
    Filed: October 14, 2010
    Date of Patent: May 17, 2011
    Assignee: Seagate Technology LLC
    Inventors: Yiran Chen, Daniel S. Reed, Yong Lu, Harry Hongyue Liu, Hai Li
  • 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: 7944730
    Abstract: A method of writing to a resistive sense memory unit includes applying a first voltage across a resistive sense memory cell and a semiconductor transistor to write a first data state to the resistive sense memory cell. The first voltage forms a first write current for a first time duration through the resistive sense memory cell in a first direction. Then the method includes applying a second voltage across the resistive sense memory cell and the transistor to write a second data state to the resistive sense memory cell. The second voltage forms a second write current for a second duration through the resistive sense memory cell in a second direction. The second direction opposes the first direction, the first voltage has a different value than the second voltage, and the first duration is substantially the same as the second duration.
    Type: Grant
    Filed: March 27, 2009
    Date of Patent: May 17, 2011
    Assignee: Seagate Technology LLC
    Inventors: Yiran Chen, Hai Li, Wengzhong Zhu, Xiaobin Wang, Ran Wang, Hongyue Liu
  • 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: 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: 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
  • 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: 7936629
    Abstract: Method and apparatus for reading data from a non-volatile memory cell, such as a modified STRAM cell. In some embodiments, at least a first and second memory cell are read for a plurality of resistance values that are used to select and store a voltage reference for each memory cell.
    Type: Grant
    Filed: January 13, 2009
    Date of Patent: May 3, 2011
    Assignee: Seagate Technology LLC
    Inventors: Henry F. Huang, Andrew J. Carter, Maroun Khoury, Yong Lu, Yiran Chen
  • Patent number: 7933137
    Abstract: Non-volatile magnetic random access memory (MRAM) devices that include magnetic flip-flop structures that include a magnetization controlling structure; a first tunnel barrier structure; and a magnetization controllable structure that includes a first polarizing layer; and a first stabilizing layer, wherein the first tunnel barrier structure is between the magnetization controllable structure and the magnetization controlling structure and the first polarizing layer is between the first stabilizing layer and the first tunnel barrier structure, wherein the magnetic flip-flop device has two stable overall magnetic configurations, and wherein a first unipolar current applied to the device will cause the orientation of the magnetization controlling structure to reverse its orientation and a second unipolar current applied to the electronic device will cause the magnetization controllable structure to switch its magnetization so that the device reaches one of the two stable overall magnetic configurations, wherein
    Type: Grant
    Filed: March 31, 2009
    Date of Patent: April 26, 2011
    Assignee: Seagate Teachnology LLC
    Inventors: Dimitar V. Dimitrov, Olle Gunnar Heinonen, Yiran Chen, Haiwen Xi, Xiaohua Lou
  • Patent number: 7933146
    Abstract: Electronic devices that include (i) a magnetization controlling structure; (ii) a tunnel barrier structure; and (iii) a magnetization controllable structure including: a first polarizing layer; and a first stabilizing layer, wherein the tunnel barrier structure is between the magnetization controlling structure and the magnetization controlling structure and the first polarizing layer is between the first stabilizing layer and the tunnel barrier structure, wherein the electronic device has two stable overall magnetic configurations, and wherein a first unipolar current applied to the electronic device will cause the orientation of the magnetization controlling structure to reverse its orientation and a second unipolar current applied to the electronic device will cause the magnetization controllable structure to switch its magnetization in order to obtain one of the two stable overall magnetic configurations, wherein the second unipolar current has an amplitude that is less than the first unipolar current.
    Type: Grant
    Filed: March 31, 2009
    Date of Patent: April 26, 2011
    Assignee: Seagate Technology LLC
    Inventors: Dimitar V. Dimitrov, Olle Gunnar Heinonen, Yiran Chen, Haiwen Xi, Xiaohua Lou
  • Publication number: 20110085373
    Abstract: Self-reference reading a magnetic tunnel junction data cell methods are disclosed. An illustrative method includes applying a read voltage across a magnetic tunnel junction data cell and forming a read current. The magnetic tunnel junction data cell has a first resistance state. The read voltage is sufficient to switch the magnetic tunnel junction data cell resistance. The method includes detecting the read current and determining if the read current remains constant during the applying step. If the read current remains constant during the applying step, then the first resistance state of the magnetic tunnel junction data cell is the resistance state that the read voltage was sufficient to switch the magnetic tunnel junction data cell to.
    Type: Application
    Filed: December 15, 2010
    Publication date: April 14, 2011
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Yuankai Zheng, Yiran Chen, Xiaobin Wang, Zheng Gao, Dimitar V. Dimitrov, Wenzhong Zhu, Yong Lu
  • 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: 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
  • 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: 20110075471
    Abstract: An apparatus and method for enhancing read and write sense margin in a memory cell having a resistive sense element (RSE), such as but not limited to a resistive random access memory (RRAM) element or a spin-torque transfer random access memory (STRAM) element. The RSE has a hard programming direction and an easy programming direction. A write current is applied in either the hard programming direction or the easy programming direction to set the RSE to a selected programmed state. A read circuit subsequently passes a read sense current through the cell in the hard programming direction to sense the selected programmed state of the cell.
    Type: Application
    Filed: December 6, 2010
    Publication date: March 31, 2011
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Wenzhong Zhu, Hai Li, Yiran Chen, Xiaobin Wang, Henry Huang, Haiwen Xi
  • 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