Patents by Inventor Yuchen Zhou

Yuchen Zhou 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: 9419207
    Abstract: The present invention is directed to a magnetic random access memory element that includes a multilayered seed structure formed by interleaving a first type sublayer and a second type sublayer to form one or more repeats of a unit bilayer structure and a first magnetic layer formed on top of the multilayered seed structure. The unit bilayer structure is made of the first and second type sublayers with at least one of the first and second type sublayers including therein one or more ferromagnetic elements. The multilayered seed structure may be amorphous or non-magnetic or both. The unit bilayer structure may be made of CoFeB and Ta sublayers.
    Type: Grant
    Filed: May 1, 2015
    Date of Patent: August 16, 2016
    Assignee: Avalanche Technology, Inc.
    Inventors: Yiming Huai, Huadong Gan, Yuchen Zhou
  • Publication number: 20160211443
    Abstract: The present invention is directed to an MRAM element comprising a magnetic free layer structure and a magnetic reference layer structure with an insulating tunnel junction layer interposed therebetween. The magnetic free layer structure has a variable magnetization direction substantially perpendicular to the layer plane thereof. The magnetic reference layer structure includes a first magnetic reference layer formed adjacent to the insulating tunnel junction layer and a second magnetic reference layer separated from the first magnetic reference layer by a first non-magnetic perpendicular enhancement layer. The first and second magnetic reference layers have a first fixed magnetization direction substantially perpendicular to the layer plane thereof.
    Type: Application
    Filed: March 24, 2016
    Publication date: July 21, 2016
    Inventors: Huadong Gan, Yiming Huai, Zihui Wang, Yuchen Zhou
  • Publication number: 20160212401
    Abstract: The current invention relates to the method to achieve re-focusable vision, including re-focusable stereo vision, with detecting the re-focusing event from a human eye. The method comprises utilizing optical and electrical sensing apparatus to detect the physiological change of viewer's eye without viewer's active participation or physical action, and retrieving the intended focus depth information of the viewer from such physiological information to update the visual impression perceived by the viewer that matches the intended focus depth, to achieve a re-focusable vision. The sensing apparatus includes both “glass” type and “contact-lens” type of see-through substrates that contain optical and electrical components that are necessary for obtaining the physiological information of viewer's eye and controlling the visual impression that the viewer perceives.
    Type: Application
    Filed: January 24, 2014
    Publication date: July 21, 2016
    Inventor: Yuchen Zhou
  • Patent number: 9396781
    Abstract: The present invention is directed to an STT-MRAM device including a plurality of magnetic tunnel junction (MTJ) memory elements. Each of the memory elements comprises a magnetic free layer structure and a magnetic reference layer structure with an insulating tunnel junction layer interposed therebetween; and a magnetic fixed layer separated from the magnetic reference layer structure by an anti-ferromagnetic coupling layer.
    Type: Grant
    Filed: February 5, 2014
    Date of Patent: July 19, 2016
    Assignee: Avalanche Technology, Inc.
    Inventors: Yuchen Zhou, Zihui Wang, Huadong Gan, Yiming Huai
  • Publication number: 20160204341
    Abstract: The present invention is directed to an MTJ memory element including a magnetic free layer structure which comprises one or more magnetic free layers that have a same variable magnetization direction substantially perpendicular to layer planes thereof; an insulating tunnel junction layer formed adjacent to the magnetic free layer structure; a magnetic reference layer structure comprising a first magnetic reference layer formed adjacent to the insulating tunnel junction layer and a second magnetic reference layer separated therefrom by a perpendicular enhancement layer with the first and second magnetic reference layers having a first fixed magnetization direction substantially perpendicular to layer planes thereof; an anti-ferromagnetic coupling layer formed adjacent to the second magnetic reference layer opposite the perpendicular enhancement layer; and a magnetic fixed layer comprising first and second magnetic fixed sublayers with the second magnetic fixed sublayer formed adjacent to the anti-ferromagnetic
    Type: Application
    Filed: February 26, 2016
    Publication date: July 14, 2016
    Inventors: Huadong Gan, Yiming Huai, Yuchen Zhou, Zihui Wang, Xiaobin Wang, Bing K. Yen, Xiaojie Hao
  • Publication number: 20160197269
    Abstract: The present invention is directed to a spin transfer torque magnetic random access memory (STTMRAM) element comprising a composite free layer including one or more stacks of a bilayer unit that comprises an insulator layer and a magnetic layer with the magnetic layer having a variable magnetization direction substantially perpendicular to a layer plane thereof; a magnetic pinned layer having a first fixed magnetization direction substantially perpendicular to a layer plane thereof; a tunnel barrier layer formed between the composite free layer and the magnetic pinned layer; and a magnetic fixed layer coupled to the magnetic pinned layer through an anti-ferromagnetic coupling layer. The magnetic fixed layer has a second fixed magnetization direction that is substantially perpendicular to a layer plane thereof and is substantially opposite to the first fixed magnetization direction.
    Type: Application
    Filed: March 16, 2016
    Publication date: July 7, 2016
    Inventors: Yiming Huai, Jing Zhang, Rajiv Yadav Ranjan, Yuchen Zhou, Roger Klas Malmhall
  • Publication number: 20160180908
    Abstract: MRAM devices that are switched by unipolar electron flow are described. Embodiments use arrays of cells that include a diode or transistor with a pMTJ. The switching between the high and low resistance states of the pMTJ is achieved by electron flow in the same direction, i.e. a unipolar flow. Embodiments of the invention include methods of operating unipolar MRAM devices that include a read step after a write step to verify the operation. Embodiments also include methods of operating unipolar MRAM devices that include an iterative stepped-voltage write process that includes a plurality of write-read steps that begin with a selected voltage for the write pulse for the first iteration and gradually increase the voltage for the write pulse for the next iteration until a successful read operation occurs.
    Type: Application
    Filed: December 18, 2015
    Publication date: June 23, 2016
    Inventors: Yuchen Zhou, Zihui Wang, Ebrahim Abedifard, Yiming Huai, Xiaojie Hao
  • Patent number: 9372785
    Abstract: A framework is described herein for identifying implicit assumptions associated with an SDK and its accompanying documentation (e.g., dev guide). An implicit assumption is information that is not expressly stated in the documentation, but which would be useful in assisting an application developer in building an application. The framework also describes a systematic approach for identifying one or more vulnerability patterns based on the identified implicit assumptions. An application developer may run a test on an application that is being developed to ensure that it does not have any deficiency which matches a vulnerability pattern.
    Type: Grant
    Filed: March 7, 2013
    Date of Patent: June 21, 2016
    Assignee: Microsoft Technology Licensing, LLC
    Inventors: Rui Wang, Yuchen Zhou, Shuo Chen, Shaz Qadeer, Yuri Gurevich
  • Patent number: 9372241
    Abstract: A method by which portions of a wafer level fabrication can be selectively heated by forming plasmon generating layers of specific size, shape, orientation and material on the fabrication and then illuminating the formation with electromagnetic radiation of such wavelength and polarization as will optimally be absorbed by the plasmon generating layers so as to generate plasmons therein. The generated plasmons thereupon produce thermal energy which is transferred to portions of the fabrication with which the plasmon generation layer has thermal contact. This method is particularly advantageous for producing multiple anneals and different magnetic pinning directions for the anti-ferromagnetic pinning layer in each of an array of GMR or TMR devices. In that process, the anti-ferromagnetic layer must be raised above its Curie temperature at which point it loses its anti-ferromagnetic properties and can have a magnetization imposed by application of an external magnetic field.
    Type: Grant
    Filed: November 6, 2009
    Date of Patent: June 21, 2016
    Assignee: Headway Technologies, Inc.
    Inventors: Yuchen Zhou, Xuhui Jin, Grace Gorman
  • Patent number: 9374298
    Abstract: In one embodiment, one or more indicia of stress are monitored. Based on the one or more indicia of stress, it is determined a stress condition exists. In response to the stress condition, one or more link aggregation actors and partners are caused to enter a grace state for a grace period. While the one or more link aggregation actors and partners are in the grace state, link aggregation formation is paced on a plurality of links by delaying formation of one or more new link aggregation groups on the plurality of links until a hold is released. Upon expiration of the grace period, the grace state is exited.
    Type: Grant
    Filed: May 8, 2012
    Date of Patent: June 21, 2016
    Assignee: CISCO TECHNOLOGY, INC.
    Inventors: Chia Alex Tsai, Yuchen Zhou, Rajagopalan Janakiraman, Yibin Yang
  • Patent number: 9349427
    Abstract: A testing method is described that applies a sequence external magnetic fields of varying strength to MRAM cells (such as those with MTJ memory elements) in chips or wafers to selectively screen out cells with low or high thermal stability factor. The coercivity (Hc) is used as a proxy for thermal stability factor (delta). In the various embodiments the sequence, direction and strength of the external magnetic fields is used to determine the high coercivity cells that are not switched by a normal field and the low coercivity cells that are switched by a selected low field. In some embodiment the MRAM's standard internal electric current can be used to switch the cells. Standard circuit-based resistance read operations can be used to determine the response of each cell to these magnetic fields and identify the abnormal high and low coercivity cells.
    Type: Grant
    Filed: August 16, 2013
    Date of Patent: May 24, 2016
    Assignee: Avalanche Technology, Inc.
    Inventors: Yuchen Zhou, Ebrahim Abedifard, Yiming Huai
  • Patent number: 9349396
    Abstract: A spin transfer oscillator with a seed/SIL/spacer/FGL/capping configuration is disclosed with a composite seed layer made of Ta and a metal layer having a fcc(111) or hcp(001) texture to enhance perpendicular magnetic anisotropy (PMA) in an overlying (A1/A2)X laminated spin injection layer (SIL). Field generation layer (FGL) is made of a high Bs material such FeCo. Alternatively, the STO has a seed/FGL/spacer/SIL/capping configuration. The SIL may include a FeCo layer that is exchanged coupled with the (A1/A2)X laminate (x is 5 to 50) to improve robustness. The FGL may include an (A1/A2)Y laminate (y=5 to 30) exchange coupled with the high Bs layer to enable easier oscillations. A1 may be one of Co, CoFe, or CoFeR where R is a metal, and A2 is one of Ni, NiCo, or NiFe. The STO may be formed between a main pole and trailing shield in a write head.
    Type: Grant
    Filed: February 20, 2015
    Date of Patent: May 24, 2016
    Assignee: Headway Technologies, Inc.
    Inventors: Kunliang Zhang, Min Li, Yuchen Zhou
  • Patent number: 9337417
    Abstract: The present invention is directed to an MRAM element comprising a magnetic free layer structure and a magnetic reference layer structure with an insulating tunnel junction layer interposed therebetween. The magnetic free layer structure has a variable magnetization direction substantially perpendicular to the layer plane thereof. The magnetic reference layer structure includes a first magnetic reference layer formed adjacent to the insulating tunnel junction layer and a second magnetic reference layer separated from the first magnetic reference layer by a first non-magnetic perpendicular enhancement layer. The first and second magnetic reference layers have a first fixed magnetization direction substantially perpendicular to the layer plane thereof.
    Type: Grant
    Filed: March 3, 2014
    Date of Patent: May 10, 2016
    Assignee: Avalanche Technology, Inc.
    Inventors: Huadong Gan, Yiming Huai, Zihui Wang, Yuchen Zhou
  • Publication number: 20160112549
    Abstract: Synchronization of traffic multiplexing in link aggregation is described. In an embodiment, a first link aggregator and a second link aggregator are associated with a plurality of links. The first link aggregator maintains an identifier for each link indicating at least a state of enabled or disabled. A synchronized clock is established between the first link aggregator and the second link aggregator. A particular link of the plurality of links is transitioned. Wherein, the transitioning is performed by the first link aggregator sending, to the second link aggregator, a first message identifying a particular time to transition the particular link. The first link aggregator receives, from the second link aggregator, a second message indicating that the particular time is acceptable. In response to a determination that the second message indicates that the particular time is acceptable and that the synchronized clock has reached the particular time, transitioning the link.
    Type: Application
    Filed: December 30, 2015
    Publication date: April 21, 2016
    Inventors: YUCHEN ZHOU, RICHARD STEWART, ALEX TSAI, YIBIN YANG
  • Patent number: 9318179
    Abstract: A spin-transfer torque magnetic random access memory (STTMRAM) element includes a composite fixed layer formed on top of a substrate and a tunnel layer formed upon the fixed layer and a composite free layer formed upon the tunnel barrier layer. The magnetization direction of each of the composite free layer and fixed layer being substantially perpendicular to the plane of the substrate. The composite layers are made of multiple repeats of a bilayer unit which consists of a non-magnetic insulating layer and magnetic layer with thicknesses adjusted in a range that makes the magnetization having a preferred direction perpendicular to film plane.
    Type: Grant
    Filed: March 13, 2015
    Date of Patent: April 19, 2016
    Assignee: Avalanche Technology, Inc.
    Inventors: Yiming Huai, Jing Zhang, Rajiv Yadav Ranjan, Yuchen Zhou, Roger Klas Malmhall
  • Patent number: 9306154
    Abstract: The present invention is directed to an MTJ memory element including a magnetic free layer structure which comprises one or more magnetic free layers that have a same variable magnetization direction substantially perpendicular to layer planes thereof; an insulating tunnel junction layer formed adjacent to the magnetic free layer structure; a magnetic reference layer structure comprising a first magnetic reference layer formed adjacent to the insulating tunnel junction layer and a second magnetic reference layer separated therefrom by a perpendicular enhancement layer with the first and second magnetic reference layers having a first fixed magnetization direction substantially perpendicular to layer planes thereof; an anti-ferromagnetic coupling layer formed adjacent to the second magnetic reference layer opposite the perpendicular enhancement layer; and a magnetic fixed layer comprising first and second magnetic fixed sublayers with the second magnetic fixed sublayer formed adjacent to the anti-ferromagnetic
    Type: Grant
    Filed: June 22, 2015
    Date of Patent: April 5, 2016
    Assignee: Avalanche Technology, Inc.
    Inventors: Huadong Gan, Zihui Wang, Xiaobin Wang, Yiming Huai, Yuchen Zhou, Bing K. Yen, Xiaojie Hao
  • Patent number: 9274184
    Abstract: A magnetic sensor with increased sensitivity, lower noise, and improved frequency response is described. The sensor's free layer is ribbon shaped and is closely flanked at each long edge by a ribbon of magnetically soft, high permeability material. The side stripes of soft magnetic material absorb external field flux and concentrate the flux to flow into the sensor's edges to promote larger MR sensor magnetization rotation. The free layer may be deposited simultaneously with the soft magnetic layer when they are aligned in the same plane. When the flux absorbing stripes are positioned above or below the MR sensor, then the free layer and flux absorbing stripes are deposited in separate steps.
    Type: Grant
    Filed: April 4, 2014
    Date of Patent: March 1, 2016
    Assignee: Headway Technologies, Inc.
    Inventors: Yuchen Zhou, Yimin Guo
  • Publication number: 20160055893
    Abstract: An STTMRAM element includes a magnetic tunnel junction (MTJ) having a perpendicular magnetic orientation. The MTJ includes a barrier layer, a free layer formed on top of the barrier layer and having a magnetic orientation that is perpendicular and switchable relative to the magnetic orientation of the fixed layer. The magnetic orientation of the free layer switches when electrical current flows through the STTMRAM element. A switching-enhancing layer (SEL), separated from the free layer by a spacer layer, is formed on top of the free layer and has an in-plane magnetic orientation and generates magneto-static fields onto the free layer, causing the magnetic moments of the outer edges of the free layer to tilt with an in-plane component while minimally disturbing the magnetic moment at the center of the free layer to ease the switching of the free layer and to reduce the threshold voltage/current.
    Type: Application
    Filed: November 2, 2015
    Publication date: February 25, 2016
    Inventors: Jing Zhang, Yiming Huai, Rajiv Yadav Ranjan, Yuchen Zhou, Zihui Wang, Xiaojie Hao
  • Patent number: 9270579
    Abstract: Synchronization of traffic multiplexing in link aggregation is described. In an embodiment, a first link aggregator and a second link aggregator are associated with a plurality of links. The first link aggregator maintains an identifier for each link indicating at least a state of enabled or disabled. A synchronized clock is established between the first link aggregator and the second link aggregator. A particular link of the plurality of links is transitioned. Wherein, the transitioning is performed by the first link aggregator sending, to the second link aggregator, a first message identifying a particular time to transition the particular link. The first link aggregator receives, from the second link aggregator, a second message indicating that the particular time is acceptable. In response to a determination that the second message indicates that the particular time is acceptable and that the synchronized clock has reached the particular time, transitioning the link.
    Type: Grant
    Filed: April 27, 2012
    Date of Patent: February 23, 2016
    Assignee: Cisco Technology, Inc.
    Inventors: Yuchen Zhou, Richard Stewart, Alex Tsai, Yibin Yang
  • Publication number: 20160047865
    Abstract: A magnetic sensor with increased sensitivity, lower noise, and improved frequency response is described. The sensor's free layer is ribbon shaped and is closely flanked at each long edge by a ribbon of magnetically soft, high permeability material. Side stripes of soft magnetic material absorb external field flux and concentrate the flux to flow into the sensor's edges to promote larger MR sensor magnetization rotation. Side stripes may be located in the plane of the free layer a maximum distance of 0.1 microns, above a plane that includes a free layer top surface, or below a plane that includes the magnetic sensor bottom surface. Edges of each side stripe may be aligned above or below a portion of the magnetic sensor. Moreover, each side stripe may have a tapered edge such that the side stripes have increasing thickness with increasing distance from the magnetic sensor.
    Type: Application
    Filed: October 29, 2015
    Publication date: February 18, 2016
    Inventors: Yuchen Zhou, Yimin Guo