Patents Assigned to EverSpin Technologies, Inc.
  • Patent number: 9910106
    Abstract: A magnetic field sensor includes a plurality of transducer legs coupled together as a first circuit to sense a magnetic field, wherein each transducer leg comprises a plurality of magnetoresistance sense elements. The magnetic field sensor also includes a second circuit including a first plurality of current lines, wherein each current line of the first plurality of current lines is adjacent to a corresponding plurality of magnetoresistance sense elements of a transducer leg of the plurality of transducer legs. When at least one current line of the first plurality of current lines is energized, a magnetization of each magnetoresistance sense element of the transducer leg is aligned in a first direction or a second direction opposite to the first direction. A routing pattern of the at least one current line is configured to generate an equal population of magnetoresistance sense elements with magnetization aligned in the first and second directions.
    Type: Grant
    Filed: April 20, 2016
    Date of Patent: March 6, 2018
    Assignee: Everspin Technologies, Inc.
    Inventors: Phillip G. Mather, Bradley Neal Engel, Guido De Sandre
  • Patent number: 9893275
    Abstract: A magnetoresistive structure having two dielectric layers, and method of manufacturing same, includes a free magnetic layer positioned between the two dielectric layers. The method of manufacture comprises at least two etch processes and at least one encapsulation process interposed therebetween wherein the encapsulation is formed on sidewalls of the partially formed magnetoresistive stack between etch processes.
    Type: Grant
    Filed: January 2, 2017
    Date of Patent: February 13, 2018
    Assignee: Everspin Technologies, Inc.
    Inventors: Sanjeev Aggarwal, Kerry Nagel, Jason Janesky
  • Patent number: 9893274
    Abstract: A semiconductor process integrates three bridge circuits, each include magnetoresistive sensors coupled as a Wheatstone bridge on a single chip to sense a magnetic field in three orthogonal directions. The process includes various deposition and etch steps forming the magnetoresistive sensors and a plurality of flux guides on one of the three bridge circuits for transferring a ā€œZā€ axis magnetic field onto sensors orientated in the XY plane.
    Type: Grant
    Filed: December 22, 2016
    Date of Patent: February 13, 2018
    Assignee: Everspin Technologies, Inc.
    Inventors: Renu Whig, Phillip Mather, Kenneth Smith, Sanjeev Aggarwal, Jon Slaughter, Nicholas Rizzo
  • Patent number: 9881695
    Abstract: In some examples, a memory device may be configured to store data in either an original or an inverted state based at least in part on a state associated with one or more shorted bit cells. For instance, the memory device may be configured to identify a shorted bit cell within a memory array and to store the data in the memory array, such that a state of the data bit stored in the shorted bit cell matches the state associated with the shorted bit cell.
    Type: Grant
    Filed: November 18, 2016
    Date of Patent: January 30, 2018
    Assignee: Everspin Technologies, Inc.
    Inventors: Thomas Andre, Jon Slaughter, Dimitri Houssameddine, Syed M. Alam
  • Publication number: 20180026180
    Abstract: A magnetoresistive magnetic tunnel junction (MTJ) stack includes a free magnetic region, a fixed magnetic region, and a dielectric layer positioned between the free magnetic region and the fixed magnetic region. In one aspect, the fixed magnetic region consists essentially of an unpinned, fixed synthetic anti-ferromagnetic (SAF) structure which comprises (i) a first layer of one or more ferromagnetic materials, including cobalt, (ii) a multi-layer region including a plurality of layers of ferromagnetic materials, wherein the plurality of layers of ferromagnetic materials include a layer of one or more ferromagnetic materials including cobalt, and (iii) an anti-ferromagnetic coupling layer disposed between the first layer and the multi-layer region. The free magnetic region may include a circular shape, the one or more ferromagnetic materials of the first layer may include cobalt, iron and boron, and the dielectric layer may be disposed on the first layer.
    Type: Application
    Filed: October 2, 2017
    Publication date: January 25, 2018
    Applicant: Everspin Technologies, Inc.
    Inventors: Srinivas V. PIETAMBARAM, Bengt J. AKERMAN, Renu WHIG, Jason A. JANESKY, Nicholas D. RIZZO, Jon M. SLAUGHTER
  • Patent number: 9870812
    Abstract: In some examples, a memory device is configured to receive a precharge command and an activate command. The memory device performs a first series of events related to the precharge command in response to receiving the precharge command and a second series of events related to the activate command in response to receiving the activate command. The memory device delays the start of the second series of events until the first series of events completes.
    Type: Grant
    Filed: December 6, 2016
    Date of Patent: January 16, 2018
    Assignee: EVERSPIN TECHNOLOGIES, INC.
    Inventors: Thomas Andre, Syed M. Alam, Halbert S. Lin
  • Patent number: 9865804
    Abstract: A magnetoresistive-based device and method of manufacturing a magnetoresistive-based device using one or more hard masks. The process of manufacture, in one embodiment, includes patterning a mask over a selected portion of the third layer of ferromagnetic material, wherein the mask is a metal hard mask. Thereafter, etching through the third layer of ferromagnetic material to provide sidewalls of the second synthetic antiferromagnetic structure, through the second tunnel barrier layer to form a second tunnel barrier and provide sidewalls thereof and the second layer of ferromagnetic material to provide sidewalls thereof. Thereafter, etching, through the first tunnel barrier layer to form a first tunnel barrier to provide sidewalls thereof and etching the first layer of ferromagnetic material to provide sidewalls thereof. The process may then include oxidizing the sidewalls of (i) the first tunnel barrier and (ii) the first layer of ferromagnetic material.
    Type: Grant
    Filed: June 22, 2017
    Date of Patent: January 9, 2018
    Assignee: Everspin Technologies, Inc.
    Inventors: Sarin A. Deshpande, Sanjeev Aggarwal, Kerry Joseph Nagel
  • Patent number: 9847116
    Abstract: A cell bias control circuit maximizes the performance of devices in the read/write path of memory cells (magnetic tunnel junction device+transistor) without exceeding leakage current or reliability limits by automatically adjusting multiple control inputs of the read/write path at the memory array according to predefined profiles over supply voltage, temperature, and process corner variations by applying any specific reference parameter profiles to the memory array.
    Type: Grant
    Filed: December 5, 2016
    Date of Patent: December 19, 2017
    Assignee: EVERSPIN TECHNOLOGIES, INC.
    Inventors: Dietmar Gogl, Syed M. Alam, Thomas Andre
  • Patent number: 9837603
    Abstract: Encapsulation of the magnetoresistive device after formation protects the sidewalls of the magnetoresistive device from degradation during subsequent deposition of interlayer dielectric material. The encapsulation also helps prevent short circuits between the top electrode of the magnetoresistive device and underlying layers within the magnetoresistive device. The encapsulation can be accomplished by depositing a layer of encapsulating material after device formation, where an etch back operation selectively removes the portions of the layer of encapsulating material other than the material on the sidewalls of the magnetoresistive device.
    Type: Grant
    Filed: October 12, 2016
    Date of Patent: December 5, 2017
    Assignee: EVERSPIN TECHNOLOGIES, INC.
    Inventors: Sarin A. Deshpande, Sanjeev Aggarwal
  • Publication number: 20170337959
    Abstract: In some examples, a nonvolatile storage element may be configured to store a state or value during a low power or powered down period of a circuit. For example, the nonvolatile storage element may include a bridge of resistive elements that have a resistive state that may be configured by applying voltages to multiple drive paths. A sense amplifier may be connected to the bridge in order to resolve a voltage differential associated with the bridge to ether power or ground and, thereby determine the state associated with on the nonvolatile storage element.
    Type: Application
    Filed: August 9, 2017
    Publication date: November 23, 2017
    Applicant: EVERSPIN TECHNOLOGIES, INC.
    Inventor: Thomas ANDRE
  • Publication number: 20170301857
    Abstract: Methods for manufacturing magnetoresistive devices are presented in which isolation of magnetic layers in the magnetoresistive stack is achieved by oxidizing exposed sidewalls of the magnetic layers and then depositing additional encapsulating material prior to subsequent etching steps. Etching the magnetic layers using a non-reactive gas further prevents degradation of the sidewalls.
    Type: Application
    Filed: June 30, 2017
    Publication date: October 19, 2017
    Applicant: Everspin Technologies, Inc.
    Inventors: Chaitanya MUDIVARTHI, Sarin A. DESHPANDE, Sanjeev AGGARWAL
  • Publication number: 20170301384
    Abstract: An apparatus used in a self-referenced read of a memory bit cell includes circuitry including a plurality of transistors that includes an NMOS-follower transistor for applying a read voltage to a first end of the bit cell. An offset current is applied by an offset current transistor. A transmission gate allows for isolation of a capacitor used to store a sample voltage corresponding to the read voltage applied across the memory bit cell.
    Type: Application
    Filed: June 29, 2017
    Publication date: October 19, 2017
    Applicant: Everspin Technologies, Inc.
    Inventors: Thomas ANDRE, Syed M. ALAM, Chitra SUBRAMANIAN
  • Patent number: 9793470
    Abstract: A method of manufacturing a magnetoresistive stack/structure comprising etching through a second magnetic region to (i) provide sidewalls of the second magnetic region and (ii) expose a surface of a dielectric layer; depositing a first encapsulation layer on the sidewalls of the second magnetic region and over the dielectric layer; etching (i) the first encapsulation layer which is disposed over the exposed surface of the dielectric layer and (ii) re-deposited material disposed on the dielectric layer, wherein, thereafter a portion of the first encapsulation layer remains on the sidewalls of the second magnetic region. The method further includes depositing a second encapsulation layer: (i) on the first encapsulation layer disposed on the sidewalls of the second magnetic region and (ii) over the exposed surface of the dielectric layer; and etching the remaining layers of the stack/structure (via one or more etch processes).
    Type: Grant
    Filed: February 2, 2016
    Date of Patent: October 17, 2017
    Assignee: Everspin Technologies, Inc.
    Inventors: Sarin A. Deshpande, Kerry Joseph Nagel, Chaitanya Mudivarthi, Sanjeev Aggarwal
  • Patent number: 9793468
    Abstract: A magnetoresistive magnetic tunnel junction (MTJ) stack includes a free magnetic region, a fixed magnetic region, and a dielectric layer positioned between the free magnetic region and the fixed magnetic region. In one aspect, the fixed magnetic region consists essentially of an unpinned, fixed synthetic anti-ferromagnetic (SAF) structure which comprises (i) a first layer of one or more ferromagnetic materials, including cobalt, (ii) a multi-layer region including a plurality of layers of ferromagnetic materials, wherein the plurality of layers of ferromagnetic materials include a layer of one or more ferromagnetic materials including cobalt, and (iii) an anti-ferromagnetic coupling layer disposed between the first layer and the multi-layer region. The free magnetic region may include a circular shape, the one or more ferromagnetic materials of the first layer may include cobalt, iron and boron, and the dielectric layer may be disposed on the first layer.
    Type: Grant
    Filed: June 30, 2016
    Date of Patent: October 17, 2017
    Assignee: Everspin Technologies, Inc.
    Inventors: Srinivas V. Pietambaram, Bengt J. Akerman, Renu Whig, Jason A. Janesky, Nicholas D. Rizzo, Jon M. Slaughter
  • Patent number: 9786838
    Abstract: An integrated circuit package including an integrated circuit die including a first side and a second side opposite the first side, the first side including at least one magnetoresistive device formed thereon. The integrated circuit package also may include a first magnetic shield disposed on or adjacent the first side of the integrated circuit die, wherein the first magnetic shield is formed of a composite material.
    Type: Grant
    Filed: October 11, 2016
    Date of Patent: October 10, 2017
    Assignee: Everspin Technologies, Inc.
    Inventor: Angelo V. Ugge
  • Patent number: 9773970
    Abstract: A magnetic field sensor including a first plurality and a second plurality of magnetoresistive sensors, wherein each magnetoresistive sensor of the first plurality and the second plurality of magnetoresistive sensors comprises: an electrode; a reference layer adjacent to the electrode, wherein the reference layer includes a synthetic antiferromagnetic structure; a magnetic sense element; and an intermediate layer between the reference layer and the magnetic sense element; and one or more conductors configured to electrically couple the magnetoresistive sensors of the first plurality and the second plurality in various configurations.
    Type: Grant
    Filed: February 11, 2016
    Date of Patent: September 26, 2017
    Assignee: EVERSPIN TECHNOLOGIES, INC.
    Inventors: Phillip Mather, Jon Slaughter, Nicholas Rizzo
  • Patent number: 9766301
    Abstract: A magnitude and direction of at least one of a reset current and a second stabilization current (that produces a reset field and a second stabilization field, respectively) is determined that, when applied to an array of magnetic sense elements, minimizes the total required stabilization field and reset field during the operation of the magnetic sensor and the measurement of the external field. Therefore, the low field sensor operates optimally (with the highest sensitivity and the lowest power consumption) around the fixed external field operating point. The fixed external field is created by other components in the sensor device housing (such as speaker magnets) which have a high but static field with respect to the low (earth's) magnetic field that describes orientation information.
    Type: Grant
    Filed: November 30, 2015
    Date of Patent: September 19, 2017
    Assignee: EVERSPIN TECHNOLOGIES, INC.
    Inventors: Lianjun Liu, Phillip Mather, Jon Slaughter
  • Publication number: 20170263300
    Abstract: A memory device is configured to identify a set of bit cells to be changed from a first state to a second state. In some examples, the memory device may apply a first voltage to the set of bit cells to change a least a first portion of the set of bit cells to the second state. In some cases, the memory device may also identify a second portion of the bit cells that remained in the first state following the application of the first voltage. In these cases, the memory device may apply a second voltage having a greater magnitude, duration, or both to the second portion of the set of bit cells in order to set the second portion of bit cells to the second state.
    Type: Application
    Filed: May 25, 2017
    Publication date: September 14, 2017
    Applicant: EVERSPIN TECHNOLOGIES, INC.
    Inventors: Thomas ANDRE, Dimitri HOUSSAMEDDINE, Syed M. ALAM, Jon SLAUGHTER, Chitra SUBRAMANIAN
  • Patent number: 9754652
    Abstract: In some examples, a nonvolatile storage element may be configured to store a state or value during a low power or powered down period of a circuit. For example, the nonvolatile storage element may include a bridge of resistive elements that have a resistive state that may be configured by applying voltages to multiple drive paths. A sense amplifier may be connected to the bridge in order to resolve a voltage differential associated with the bridge to either power or ground and, thereby determine the state associated with on the nonvolatile storage element.
    Type: Grant
    Filed: May 9, 2016
    Date of Patent: September 5, 2017
    Assignee: Everspin Technologies, Inc.
    Inventor: Thomas Andre
  • Patent number: 9740431
    Abstract: A memory system and memory controller for interleaving volatile and non-volatile memory accesses are described. In the memory system, the memory controller is coupled to the volatile and non-volatile memories using a shared address bus. Activate latencies for the volatile and non-volatile memories are different, and registers are included on the memory controller for storing latency values. Additional registers on the memory controller store precharge latencies for the memories as well as page size for the non-volatile memory. A memory access sequencer on the memory controller asserts appropriate chip select signals to the memories to initiate operations therein.
    Type: Grant
    Filed: July 17, 2016
    Date of Patent: August 22, 2017
    Assignee: EVERSPIN TECHNOLOGIES, INC.
    Inventors: Syed M. Alam, Thomas Andre, Dietmar Gogl