Patents by Inventor Xiaobin Wang

Xiaobin Wang 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: 20120257447
    Abstract: A magnetic tunnel junction having a compsensation element is disclosed. The magnetic tunnel junction includes a reference element, and a compensation element having an opposite magnetization moment to a magnetization moment of the reference element. A free magnetic layer is between the reference element and the compensation element, and an electrically insulating and non-magnetic tunneling barrier layer separates the free magnetic layer from the reference element. The free magnetic layer includes Co100-X-YFeXBY wherein X is a value being greater than 30 and Y is a value being greater than 15.
    Type: Application
    Filed: June 20, 2012
    Publication date: October 11, 2012
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Yuankai Zheng, Dimitar V. Dimitrov, Dexin Wang, Wei Tian, Xiaobin Wang, Xiaohua Lou
  • Patent number: 8283723
    Abstract: A semiconductor device is formed on a semiconductor substrate. The device includes a drain, an epitaxial layer overlaying the drain, and an active region. The active region includes a body disposed in the epitaxial layer, having a body top surface, a source embedded in the body, extending from the body top surface into the body, a gate trench extending into the epitaxial layer, a gate disposed in the gate trench, an active region contact trench extending through the source and into the body, an active region contact electrode disposed within the active region contact trench, wherein a thin layer of body region separating the active region contact electrode from the drain.
    Type: Grant
    Filed: December 21, 2007
    Date of Patent: October 9, 2012
    Assignee: Alpha & Omega Semiconductor Limited
    Inventors: Anup Bhalla, Xiaobin Wang, Ji Pan, Sung-Po Wei
  • Publication number: 20120250404
    Abstract: A magnetic tunnel junction device includes a reference magnetic layer and a magnetic free layer including first and second magnetic elements that are magnetically exchange coupled. The magnetic exchange coupling between the first and second magnetic elements is configured to achieve a switching current distribution less than about 200% and a long term thermal stability criterion of greater than about 60 kBT.
    Type: Application
    Filed: March 31, 2011
    Publication date: October 4, 2012
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Xiaobin Wang, Kaizhong Gao
  • Publication number: 20120251845
    Abstract: Approaches to reduce switching field distribution in energy assisted magnetic storage devices involve first and second exchange coupled magnetic elements. The first magnetic elements have anisotropy, Hk1, volume, V1 and the second magnetic elements are magnetically exchange coupled to the first magnetic elements and have anisotropy Hk2, and volume V2. The thermal stability of the exchange coupled magnetic elements is greater than about 60 kBT at a storage temperature of about 300 K. The magnetic switching field distribution, SFD, of the exchange coupled magnetic elements is less than about 200% at a predetermined magnetic switching field and a predetermined assisting switching energy.
    Type: Application
    Filed: March 31, 2011
    Publication date: October 4, 2012
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Xiaobin Wang, Kaizhong Gao
  • Publication number: 20120250405
    Abstract: Memory units that have a magnetic tunnel junction cell that utilizes spin torque and a current induced magnetic field to assist in the switching of the magnetization orientation of the free layer of the magnetic tunnel junction cell. The memory unit includes a spin torque current source for passing a current through the magnetic tunnel junction cell, the spin torque current source having a direction perpendicular to the magnetization orientations, and also includes a magnetic ampere field current source is oriented in a direction orthogonal or at some angles to the magnetization orientations.
    Type: Application
    Filed: June 8, 2012
    Publication date: October 4, 2012
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Xiaobin Wang, Haiwen Xi, Hongyue Liu, Insik Jin, Andreas Roelofs, Eileen Yan, Dimitar V. Dimitrov
  • Patent number: 8270204
    Abstract: Magnetic shift tracks or magnetic strips, to which application of a rotating magnetic field or by rotation of the strip itself allows accurate determination of domain wall movement. One particular embodiment is a method of determining a position of a domain wall in a magnetic strip. The method includes applying a rotating magnetic field to the magnetic strip, the magnetic field rotating around a longitudinal axis of the magnetic strip, and after applying the magnetic field, determining a displacement of the domain wall to a second position.
    Type: Grant
    Filed: July 9, 2009
    Date of Patent: September 18, 2012
    Assignee: Seagate Technology LLC
    Inventors: Xiaobin Wang, Haiwen Xi, Yiran Chen, Yuan Yan, Jun Zheng
  • Publication number: 20120224417
    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: Application
    Filed: May 16, 2012
    Publication date: September 6, 2012
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Xuguang Wang, Yiran Chen, Dimitar V. Dimitrov, Hongyue Liu, Xiaobin Wang
  • Patent number: 8253192
    Abstract: A semiconductor device includes a drain region comprising an epitaxial layer, a body disposed in the epitaxial layer, a source embedded in the body, a gate trench extending into the epitaxial layer, a gate disposed in the gate trench, an active region contact trench extending through the source, and an active region contact electrode disposed within the active region contact trench. The active region contact trench has a first width associated with a first region that is in proximity to a bottom portion of the body and a second width associated with a second region that is in proximity to a bottom portion of the source. The first width is substantially different from the second width.
    Type: Grant
    Filed: April 15, 2011
    Date of Patent: August 28, 2012
    Assignee: Alpha and Omega Semiconductor Incorporated
    Inventors: Anup Bhalla, Xiaobin Wang
  • Patent number: 8247297
    Abstract: A method is disclosed for creating a semiconductor device structure with an oxide-filled large deep trench (OFLDT) portion having trench size TCS and trench depth TCD. A bulk semiconductor layer (BSL) is provided with a thickness BSLT>TCD. A large trench top area (LTTA) is mapped out atop BSL with its geometry equal to OFLDT. The LTTA is partitioned into interspersed, complementary interim areas ITA-A and ITA-B. Numerous interim vertical trenches of depth TCD are created into the top BSL surface by removing bulk semiconductor materials corresponding to ITA-B. The remaining bulk semiconductor materials corresponding to ITA-A are converted into oxide. If any residual space is still left between the so-converted ITA-A, the residual space is filled up with oxide deposition. Importantly, the geometry of all ITA-A and ITA-B should be configured simple and small enough to facilitate fast and efficient processes of oxide conversion and oxide filling.
    Type: Grant
    Filed: December 15, 2009
    Date of Patent: August 21, 2012
    Assignee: Alpha & Omega Semiconductor Inc.
    Inventors: Xiaobin Wang, Anup Bhalla, Yeeheng Lee
  • Patent number: 8247329
    Abstract: A method for forming a semiconductor device includes forming a nanotube region using a thin epitaxial layer formed on the sidewall of a trench in the semiconductor body. The thin epitaxial layer has uniform doping concentration. In another embodiment, a first thin epitaxial layer of the same conductivity type as the semiconductor body is formed on the sidewall of a trench in the semiconductor body and a second thin epitaxial layer of the opposite conductivity type is formed on the first epitaxial layer. The first and second epitaxial layers have uniform doping concentration. The thickness and doping concentrations of the first and second epitaxial layers and the semiconductor body are selected to achieve charge balance. In one embodiment, the semiconductor body is a lightly doped P-type substrate. A vertical trench MOSFET, an IGBT, a Schottky diode and a P-N junction diode can be formed using the same N-Epi/P-Epi nanotube structure.
    Type: Grant
    Filed: February 9, 2011
    Date of Patent: August 21, 2012
    Assignee: Alpha & Omega Semiconductor, Inc.
    Inventors: Hamza Yilmaz, Xiaobin Wang, Anup Bhalla, John Chen, Hong Chang
  • Patent number: 8223532
    Abstract: Memory units that have a magnetic tunnel junction cell that utilizes spin torque and a current induced magnetic field to assist in the switching of the magnetization orientation of the free layer of the magnetic tunnel junction cell. The memory unit includes a spin torque current source for passing a current through the magnetic tunnel junction cell, the spin torque current source having a direction perpendicular to the magnetization orientations, and also includes a magnetic ampere field current source is oriented in a direction orthogonal or at some angles to the magnetization orientations.
    Type: Grant
    Filed: August 27, 2008
    Date of Patent: July 17, 2012
    Assignee: Seagate Technology LLC
    Inventors: Xiaobin Wang, Haiwen Xi, Hongyue Liu, Insik Jin, Andreas Roelofs, Eileen Yan, Dimitar V. Dimitrov
  • Patent number: 8213222
    Abstract: A magnetic tunnel junction having a compsensation element is disclosed. The magnetic tunnel junction includes a reference element, and a compensation element having an opposite magnetization moment to a magnetization moment of the reference element. A free magnetic layer is between the reference element and the compensation element, and an electrically insulating and non-magnetic tunneling barrier layer separates the free magnetic layer from the reference element. The free magnetic layer includes Co100-X-YFeXBY wherein X is a value being greater than 30 and Y is a value being greater than 15.
    Type: Grant
    Filed: August 16, 2011
    Date of Patent: July 3, 2012
    Assignee: Seagate Technology LLC
    Inventors: Yuankai Zheng, Dimitar V. Dimitrov, Dexin Wang, Wei Tian, Xiaobin Wang, Xiaohua Lou
  • Patent number: 8213215
    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: Grant
    Filed: January 27, 2011
    Date of Patent: July 3, 2012
    Assignee: Seagate Technology LLC
    Inventors: Yiran Chen, Hai Li, Wenzhong Zhu, Xiaobin Wang, Henry Huang, Hongyue Liu
  • Publication number: 20120163065
    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: March 2, 2012
    Publication date: June 28, 2012
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Yiran Chen, Hai Li, Wenzhong Zhu, Xiaobin Wang, Henry Huang, Hongyue Liu
  • Patent number: 8203862
    Abstract: An apparatus and associated method for generating a reference voltage with dummy resistive sense element regions. A first resistance distribution is obtained for a first dummy region of resistance sense elements and a second resistance distribution is obtained for a second dummy region of resistive sense elements. A user resistive sense element from a user region is assigned to a selected resistive sense element of one of the first or second dummy regions in relation to the first and second resistance distributions.
    Type: Grant
    Filed: July 13, 2009
    Date of Patent: June 19, 2012
    Assignee: Seagate Technology LLC
    Inventors: Yiran Chen, Hai Li, Wenzhong Zhu, Xiaobin Wang, Yuan Yan, Harry Hongyue Liu
  • Patent number: 8203899
    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: Grant
    Filed: November 15, 2010
    Date of Patent: June 19, 2012
    Assignee: Seagate Technology LLC
    Inventors: Yiran Chen, Hai Li, Wenzhong Zhu, Xiaobin Wang, Ran Wang, Harry Hongyue Liu
  • Publication number: 20120147665
    Abstract: Method and apparatus for using thermal preconditioning to write data to a non-volatile memory cell. In accordance with some embodiments, a semiconductor memory has an array of non-volatile memory cells, and a control circuit which stores a first write command from a host to write data to said array. A write circuit flows a write current through an unconditioned first selected cell having a first block address associated with the first write command to write the first selected cell to a selected data state, and concurrently passes a thermal preconditioning current through a second selected cell having a second block address associated with the first block address. The write circuit further passes a thermal preconditioning current through a third selected cell having a third block address associated with the second block address in response to receipt by the control circuit of a second write command from the host associated with the second block address.
    Type: Application
    Filed: February 20, 2012
    Publication date: June 14, 2012
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Yiran Chen, Hai Li, Harry Hongyue Liu, Dimitar V. Dimitrov, Alan Xuguang Wang, Xiaobin Wang
  • Patent number: 8198660
    Abstract: A multi-bit spin torque magnetic element that has a ferromagnetic pinned layer having a pinned magnetization orientation, a non-magnetic layer, and a ferromagnetic free layer having a magnetization orientation switchable among at least four directions, the at least four directions being defined by a physical shape of the free layer. The magnetic element has at least four distinct resistance states. Magnetic elements with at least eight magnetization directions are also provided.
    Type: Grant
    Filed: August 27, 2010
    Date of Patent: June 12, 2012
    Assignee: Seagate Technology LLC
    Inventors: Dimitar V. Dimitrov, Zheng Gao, Xiaobin Wang
  • Patent number: 8199562
    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: Grant
    Filed: December 6, 2010
    Date of Patent: June 12, 2012
    Assignee: Seagate Technology LLC
    Inventors: Wenzhong Zhu, Hai Li, Yiran Chen, Xiaobin Wang, Henry Huang, Haiwen Xi
  • Patent number: 8199569
    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: April 15, 2011
    Date of Patent: June 12, 2012
    Assignee: Seagate Technology LLC
    Inventors: Xuguang Wang, Yiran Chen, Dimitar V. Dimitrov, Hongyue Liu, Xiaobin Wang