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).
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Patent number: 7826260Abstract: 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: GrantFiled: February 17, 2009Date of Patent: November 2, 2010Assignee: Seagate Technology LLCInventors: Wenzhong Zhu, Yiran Chen, Xiaobin Wang, Zheng Gao, Haiwen Xi, Dimitar V. Dimitrov
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Patent number: 7826255Abstract: 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: GrantFiled: September 15, 2008Date of Patent: November 2, 2010Assignee: Seagate Technology LLCInventors: Haiwen Xi, Hongyue Liu, Xiaobin Wang, Yong Lu, Yiran Chen, Yuankai Zheng, Dimitar V. Dimitrov, Dexin Wang, Hai Li
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Patent number: 7813168Abstract: 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: GrantFiled: February 17, 2009Date of Patent: October 12, 2010Assignee: Seagate Technology LLCInventors: Wenzhong Zhu, Yiran Chen, Dimitar V. Dimitrov, Xiaobin Wang
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Publication number: 20100246251Abstract: 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: ApplicationFiled: March 30, 2009Publication date: September 30, 2010Applicant: SEAGATE TECHNOLOGY LLCInventors: Yiran Chen, Hai Li, Harry Hongyue Liu, Dimitar V. Dimitrov, Alan Xuguang Wang, Xiaobin Wang
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Patent number: 7804709Abstract: 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: GrantFiled: July 18, 2008Date of Patent: September 28, 2010Assignee: Seagate Technology LLCInventors: Xuguang Wang, Yiran Chen, Dimitar V. Dimitrov, Hongyue Liu, Xiaobin Wang
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Publication number: 20100238712Abstract: 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: ApplicationFiled: June 4, 2010Publication date: September 23, 2010Applicant: SEAGATE TECHNOLOGY LLCInventors: Haiwen Xi, Hongyue Liu, Xiaobin Wang, Yong Lu, Yiran Chen, Yuankai Zheng, Dimitar V. Dimitrov, Dexin Wang, Hai Li
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Publication number: 20100238721Abstract: A method and apparatus for repairing a stuck-at defect condition in a non-volatile memory cell, such as a spin-torque transfer random access memory (STRAM). In some embodiments, a resistive sense element has a magnetic tunneling junction (MTJ) and a repair plane located adjacent to the resistive sense element. The repair plane injects a magnetic field in the MTJ to repair a stuck-at defect condition.Type: ApplicationFiled: March 17, 2009Publication date: September 23, 2010Applicant: SEAGATE TECHNOLOGY LLCInventors: Alan Xuguang Wang, Xiaobin Wang, Dimitar V. Dimitrov, Hai Li, Haiwen Xi, Harry Hongyue Liu
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Patent number: 7800938Abstract: 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: GrantFiled: October 15, 2008Date of Patent: September 21, 2010Assignee: Seagate Technology, LLCInventors: Kirill Rivkin, Yiran Chen, Xiaobin Wang, Haiwen Xi
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Publication number: 20100207219Abstract: A magnetic memory device includes a first electrode separated from a second electrode by a magnetic tunnel junction. The first electrode provides a write current path along a length of the first electrode. The magnetic tunnel junction includes 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. The free magnetic layer is spaced from the first electrode a distance of less than 10 nanometers. A current passing along the write current path generates a magnetic field. The magnetic field switches the free magnetic layer magnetization orientation between a high resistance state magnetization orientation and a low resistance state magnetization orientation.Type: ApplicationFiled: February 17, 2009Publication date: August 19, 2010Applicant: SEAGATE TECHNOLOGY LLCInventors: Insik Jin, Hongyue Liu, Yong Lu, Xiaobin Wang
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Patent number: 7776963Abstract: Adhesive formulations having acrylate monomer or methacrylate monomer, or mixtures thereof, and having a reducing agent and an initiator (e.g., peroxide). The formulations may include a chelating agent solution to improve storage stability and other properties. Further, the mole ratio of the initiator to the reducing agent may be adjusted to control weight loss of the adhesives during cure. Polyvinyl acetate or its derivatives may also be employed in the adhesive formulations to reduce weight loss during cure. Moreover, certain embodiments of the formulations include a toughening-agent copolymer having a glass transition temperature (of at least one domain) that is lower than ?50° C. (?58° F.). These toughening-agent copolymers may be added to the adhesive formulations to improve impact strength and other properties of the cured adhesives at lower temperatures, e.g., ?40° C. (?40° F.), while maintaining performance of the cured adhesives at higher temperatures, e.g., 82° C. (180° F.).Type: GrantFiled: May 3, 2005Date of Patent: August 17, 2010Assignee: Illinois Tool Works Inc.Inventors: Xiaobin Wang, Daniel K. Doe, Patricia M. Savory, Kenneth A. Lambert
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Publication number: 20100195380Abstract: 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: ApplicationFiled: February 3, 2009Publication date: August 5, 2010Applicant: Seagate Technology LLCInventors: Xiaobin Wang, Yong Lu, Haiwen Xi, Yuankai Zheng, Yiran Chen, Harry Hongyue Liu, Dimitar Dimitrov, Wei Tian, Brian Seungwhan Lee
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Publication number: 20100174766Abstract: A method and apparatus for generating a random logic bit value. In some embodiments, a spin polarized current is created by flowing a pulse current through a spin polarizing material. The spin polarized current is injected in a free layer of a magnetic tunneling junction and a random logical bit value results from a variation in pulse current duration or a variation in thermal properties.Type: ApplicationFiled: January 6, 2009Publication date: July 8, 2010Applicant: Seagate Technology LLCInventors: Thomas Weeks, Yong Lu, Xiaobin Wang
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Publication number: 20100128520Abstract: An apparatus that includes a magnetic structure including a reference layer; and a free layer; an exchange coupling spacer layer; and a stabilizing layer, wherein the exchange coupling spacer layer is between the magnetic structure and the stabilizing layer and exchange couples the free layer of the magnetic structure to the stabilizing layer.Type: ApplicationFiled: July 13, 2009Publication date: May 27, 2010Applicant: SEAGATE TECHNOLOGY LLCInventors: Yuankai Zheng, Dimitar V. Dimitrov, Dexin Wang, Haiwen Xi, Xiaobin Wang, Wei Tian, Xiaohua Lou
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Publication number: 20100128519Abstract: A non volatile memory assembly that includes a reference element having: a reference component; and a reference transistor, wherein the reference component is electrically connected to the reference transistor, and the reference transistor controls the passage of current across the reference component; and at least one non volatile memory element having: a non volatile memory cell, having at least a low and a high resistance state; and an output that electrically connects the reference element with the at least one non volatile memory element, wherein the reference transistor and the memory transistor are activated by a reference gate voltage and a memory gate voltage respectively, and the reference gate voltage and the memory gate voltage are not the same.Type: ApplicationFiled: July 9, 2009Publication date: May 27, 2010Applicant: SEAGATE TECHNOLOGY LLCInventors: Hai Li, Yiran Chen, Xiaobin Wang, Yuan Yan
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Publication number: 20100110761Abstract: 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: ApplicationFiled: March 5, 2009Publication date: May 6, 2010Applicant: SEAGATE TECHNOLOGY LLCInventors: Yiran Chen, Hai Li, Wenzhong Zhu, Xiaobin Wang, Henry Huang, Hongyue Liu
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Publication number: 20100110785Abstract: 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: ApplicationFiled: March 18, 2009Publication date: May 6, 2010Applicant: SEAGATE TECHNOLOGY LLCInventors: Yiran Chen, Hai Li, Wenzhong Zhu, Xiaobin Wang, Ran Wang, Harry Hongyue Liu
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Publication number: 20100109660Abstract: A random number generator device that utilizes a magnetic tunnel junction. An AC current source is in electrical connection to the magnetic tunnel junction to provide an AC current having an amplitude and a frequency through the free layer of the magnetic tunnel junction, the AC current configured to switch the magnetization orientation of the free layer via thermal magnetization. A read circuit is used to determine the relative orientation of the free layer magnetization in relation to the reference layer magnetization orientation.Type: ApplicationFiled: March 6, 2009Publication date: May 6, 2010Applicant: SEAGATE TECHNOLOGY LLCInventors: Xiaobin Wang, Wenzhong Zhu, Henry Huang, Yiran Chen, Haiwen Xi
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Publication number: 20100110784Abstract: 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: ApplicationFiled: February 20, 2009Publication date: May 6, 2010Applicant: SEAGATE TECHNOLOGY LLCInventors: Yuankai Zheng, Yiran Chen, Xiaobin Wang, Zheng Gao, Dimitar V. Dimitrov, Wenzhong Zhu, Yong Lu
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Publication number: 20100110762Abstract: 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: ApplicationFiled: March 27, 2009Publication date: May 6, 2010Applicant: SEAGATE TECHNOLOGY LLCInventors: Yiran Chen, Hai Li, Wengzhong Zhu, Xiaobin Wang, Ran Wang, Hongyue Liu
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Publication number: 20100109656Abstract: 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: ApplicationFiled: February 9, 2009Publication date: May 6, 2010Applicant: SEAGATE TECHNOLOGY LLCInventors: Xiaobin Wang, Yiran Chen, Alan Wang, Haiwen Xi, Wenzhong Zhu, Hai Li, Hongyue Liu