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).

  • Patent number: 7830700
    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: November 12, 2008
    Date of Patent: November 9, 2010
    Assignee: Seagate Technology LLC
    Inventors: Yiran Chen, Daniel S. Reed, Yong Lu, Harry Hongyue Liu, Hai Li
  • Patent number: 7826255
    Abstract: Variable write and read methods for resistance random access memory (RRAM) are disclosed. The methods include initializing a write sequence and verifying the resistance state of the RRAM cell. If a write pulse is needed, then two or more write pulses are applied through the RRAM cell to write the desired data state to the RRAM cell. Each subsequent write pulse has substantially the same or greater write pulse duration. Subsequent write pulses are applied to the RRAM cell until the RRAM cell is in the desired data state or until a predetermined number of write pulses have been applied to the RRAM cell. A read method is also disclosed where subsequent read pulses are applied through the RRAM cell until the read is successful or until a predetermined number of read pulses have been applied to the RRAM cell.
    Type: Grant
    Filed: September 15, 2008
    Date of Patent: November 2, 2010
    Assignee: Seagate Technology LLC
    Inventors: Haiwen Xi, Hongyue Liu, Xiaobin Wang, Yong Lu, Yiran Chen, Yuankai Zheng, Dimitar V. Dimitrov, Dexin Wang, Hai Li
  • Patent number: 7826260
    Abstract: A spin-transfer torque memory apparatus and self-reference read and write assist schemes are described. One method of self-reference reading a spin-transfer torque memory unit includes applying a first read current through a magnetic tunnel junction data cell and forming a first bit line read voltage and storing the first bit line read voltage. A magnetic field is applied through the free magnetic layer the forming a magnetic field modified magnetic tunnel junction data cell, the magnetic field rotates the magnetization orientation of the free magnetic layer without switching a resistance state of the magnetic tunnel junction data cell.
    Type: Grant
    Filed: February 17, 2009
    Date of Patent: November 2, 2010
    Assignee: Seagate Technology LLC
    Inventors: Wenzhong Zhu, Yiran Chen, Xiaobin Wang, Zheng Gao, Haiwen Xi, Dimitar V. Dimitrov
  • Patent number: 7813168
    Abstract: A spin-transfer torque memory apparatus and self-reference read and write assist schemes are described. One method of self-reference reading a spin-transfer torque memory unit includes applying a first read current through a magnetic tunnel junction data cell and forming a first bit line read voltage and storing the first bit line read voltage. A magnetic field is applied through the magnetic tunnel junction data cell forming a magnetic field modified magnetic tunnel junction data cell. Then a second read current is applied thorough the magnetic field modified magnetic tunnel junction data cell forming a second bit line read voltage and the bit line read voltage is stored and compared with the first bit line read voltage to determine whether the first resistance state of the magnetic tunnel junction data cell was a high resistance state or low resistance state. Methods of applying a magnetic field to the MTJ and then writing the desired resistance state are also disclosed.
    Type: Grant
    Filed: February 17, 2009
    Date of Patent: October 12, 2010
    Assignee: Seagate Technology LLC
    Inventors: Wenzhong Zhu, Yiran Chen, Dimitar V. Dimitrov, Xiaobin Wang
  • Publication number: 20100246251
    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: Application
    Filed: March 30, 2009
    Publication date: September 30, 2010
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Yiran Chen, Hai Li, Harry Hongyue Liu, Dimitar V. Dimitrov, Alan Xuguang Wang, Xiaobin Wang
  • Publication number: 20100246250
    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: Application
    Filed: March 24, 2009
    Publication date: September 30, 2010
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Yiran Chen, Hai Li, Harry Hongyue Liu, KangYong Kim, Henry F. Huang
  • Patent number: 7804709
    Abstract: A 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: July 18, 2008
    Date of Patent: September 28, 2010
    Assignee: Seagate Technology LLC
    Inventors: Xuguang Wang, Yiran Chen, Dimitar V. Dimitrov, Hongyue Liu, Xiaobin Wang
  • Publication number: 20100238700
    Abstract: A method and apparatus for testing an array of non-volatile memory cells, such as a spin-torque transfer random access memory (STRAM). In some embodiments, an array of memory cells having a plurality of unit cells with a resistive sense element and a switching device has a row decoder and a column decoder connected to the plurality of unit cells. A test circuitry sends a non-operational test pattern through the array via the row and column decoders with a quiescent supply current to identify defects in the array of memory cells.
    Type: Application
    Filed: March 17, 2009
    Publication date: September 23, 2010
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Hai Li, Yiran Chen, Alan Xuguang Wang, Haiwen Xi, Wenzhong Zhu, Andreas K. Roelofs
  • Publication number: 20100238712
    Abstract: Variable write and read methods for resistance random access memory (RRAM) are disclosed. The methods include initializing a write sequence and verifying the resistance state of the RRAM cell. If a write pulse is needed, then two or more write pulses are applied through the RRAM cell to write the desired data state to the RRAM cell. Each subsequent write pulse has substantially the same or greater write pulse duration. Subsequent write pulses are applied to the RRAM cell until the RRAM cell is in the desired data state or until a predetermined number of write pulses have been applied to the RRAM cell. A read method is also disclosed where subsequent read pulses are applied through the RRAM cell until the read is successful or until a predetermined number of read pulses have been applied to the RRAM cell.
    Type: Application
    Filed: June 4, 2010
    Publication date: September 23, 2010
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Haiwen Xi, Hongyue Liu, Xiaobin Wang, Yong Lu, Yiran Chen, Yuankai Zheng, Dimitar V. Dimitrov, Dexin Wang, Hai Li
  • Patent number: 7800938
    Abstract: A memory unit having a spin torque memory cell with a ferromagnetic free layer, a ferromagnetic pinned layer and a spacer layer therebetween, with the free layer having a switchable magnetization orientation with a switching threshold. A DC current source is electrically connected to the spin torque memory cell to cause spin transfer torque in the free layer. An AC current source is electrically connected to the spin torque memory cell to produce an oscillatory polarized current capable of spin transfer torque via resonant coupling with the free layer.
    Type: Grant
    Filed: October 15, 2008
    Date of Patent: September 21, 2010
    Assignee: Seagate Technology, LLC
    Inventors: Kirill Rivkin, Yiran Chen, Xiaobin Wang, Haiwen Xi
  • Publication number: 20100232206
    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: Application
    Filed: March 10, 2009
    Publication date: September 16, 2010
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Hai Li, Yiran Chen, Harry Hongyue Liu, Alan Xuguang Wang
  • Publication number: 20100232211
    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: Application
    Filed: May 28, 2010
    Publication date: September 16, 2010
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Hongyue Liu, Yong Lu, Andrew Carter, Yiran Chen, Hai Li
  • Publication number: 20100228912
    Abstract: Various embodiments of the present invention are generally directed to an apparatus and associated method for a non-volatile memory with a hybrid index tag array. In accordance with some embodiments, a memory device has a word memory array formed of non-volatile resistive sense memory (RSM) cells, a first index array formed of volatile content addressable memory (CAM) cells, and a second index array formed of non-volatile RSM cells. The memory device is configured to output word data from the word memory array during a data retrieval operation when input request data matches tag data stored in the first index array, and to copy tag data stored in the second index array to the first index array during a device reinitialization operation.
    Type: Application
    Filed: March 4, 2009
    Publication date: September 9, 2010
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Henry Huang, Yiran Chen
  • Publication number: 20100220512
    Abstract: Various embodiments of the present invention are generally directed to an apparatus comprising a programmable power source which uses an array of resistive sense memory cells, such as but not limited to STRAM or RRAM cells, to provide a controlled power bias to a load, such as but not limited to a micro-oscillator. In some embodiments, the programmable power source incorporates an array of serially connected resistive sense memory cells. A selectively controllable power level is applied by the programmable power source to a load in relation to a control input which selectively programs at least selected ones of the memory cells to a selected resistance state.
    Type: Application
    Filed: March 2, 2009
    Publication date: September 2, 2010
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Yiran Chen, Insik Jin, Hai Li, Dimitar V. Dimitrov, Dexin Wang
  • Publication number: 20100195380
    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: Application
    Filed: February 3, 2009
    Publication date: August 5, 2010
    Applicant: Seagate Technology LLC
    Inventors: Xiaobin Wang, Yong Lu, Haiwen Xi, Yuankai Zheng, Yiran Chen, Harry Hongyue Liu, Dimitar Dimitrov, Wei Tian, Brian Seungwhan Lee
  • Publication number: 20100188883
    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: Application
    Filed: January 28, 2009
    Publication date: July 29, 2010
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Yiran Chen, Daniel S. Reed, Yong Lu, Harry Hongyue Liu, Hai Li, Rod V. Bowman
  • Publication number: 20100177552
    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: Application
    Filed: January 13, 2009
    Publication date: July 15, 2010
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Henry F. Huang, Andrew J. Carter, Maroun Khoury, Yong Lu, Yiran Chen
  • Publication number: 20100177562
    Abstract: Various embodiments are generally directed to a method and apparatus associated with operating a first memory device with multiple interfaces and a status register. In some embodiments, a first interface is engaged by a host. A memory device that has a plurality of memory cells comprised of at least a magnetic tunneling junction and a spin polarizing magnetic material is connected to a second interface. A status register is maintained by logging at least an error or busy signal during data transfer operations through the first and second interfaces.
    Type: Application
    Filed: January 13, 2009
    Publication date: July 15, 2010
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Yiran Chen, Daniel S. Reed, Yong Lu, Harry Hongyue Liu, Hai Li, Rod V. Bowman
  • Publication number: 20100177554
    Abstract: A resistive sense memory apparatus includes a bipolar select device having a semiconductor substrate and a plurality of transistors disposed in the semiconductor substrate and forming a row or transistors. Each transistor includes an emitter contact and a collector contact. Each collector contact is electrically isolated from each other and each emitter contact is electrically isolated from each other. A gate contact extends along a channel region between the emitter contact and a collector contact. A base contact is disposed within the semiconductor substrate such that the emitter contact and a collector contact is between the gate contact and the base contact. A resistive sense memory cells is electrically coupled to each collector contact or emitter contact and a bit line.
    Type: Application
    Filed: July 13, 2009
    Publication date: July 15, 2010
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Yong Lu, Hongyue Liu, Maroun Khoury, Yiran Chen
  • Publication number: 20100177551
    Abstract: Various embodiments of the present invention are generally directed to a method and apparatus for providing different bit set modes for a resistive sense memory (RSM) array, such as a spin-torque transfer random access memory (STRAM) or resistive random access memory (RRAM) array. In accordance with some embodiments, a group of RSM cells in a non-volatile semiconductor memory array is identified for application of a bit set operation. A bit set value is selected from a plurality of bit set values each separately writable to the RSM cells to place said cells in a selected resistive state. The selected bit set value is thereafter written to at least a portion of the RSM cells in the identified group.
    Type: Application
    Filed: January 13, 2009
    Publication date: July 15, 2010
    Applicant: Seagate Technology LLC
    Inventors: Yiran Chen, Daniel S. Reed, Yong Lu, Harry Hongyue Liu, Hai Li, Rod V. Bowman