Patents Assigned to EverSpin Technologies, Inc.
  • Patent number: 10516103
    Abstract: A magnetoresistive element (e.g., a spin-torque magnetoresistive memory element) includes a fixed magnetic layer, a free magnetic layer, having a high-iron alloy interface region located along a surface of the free magnetic layer, wherein the high-iron alloy interface region has at least 50% iron by atomic composition, and a first dielectric, disposed between the fixed magnetic layer and the free magnetic layer. The magnetoresistive element further includes a second dielectric, having a first surface that is in contact with the surface of the free magnetic layer, and an electrode, disposed between the second dielectric and a conductor. The electrode includes: (i) a non-ferromagnetic portion having a surface that is in contact with a second surface of the second dielectric, and (ii) a second portion having at least one ferromagnetic material disposed between the non-ferromagnetic portion of the electrode and the conductor.
    Type: Grant
    Filed: August 27, 2019
    Date of Patent: December 24, 2019
    Assignee: Everspin Technologies, Inc.
    Inventors: Renu Whig, Jijun Sun, Nicholas Rizzo, Jon Slaughter, Dimitri Houssameddine, Frederick Mancoff
  • Publication number: 20190386212
    Abstract: A magnetoresistive element (e.g., a spin-torque magnetoresistive memory element) includes a fixed magnetic layer, a free magnetic layer, having a high-iron alloy interface region located along a surface of the free magnetic layer, wherein the high-iron alloy interface region has at least 50% iron by atomic composition, and a first dielectric, disposed between the fixed magnetic layer and the free magnetic layer. The magnetoresistive element further includes a second dielectric, having a first surface that is in contact with the surface of the free magnetic layer, and an electrode, disposed between the second dielectric and a conductor. The electrode includes: (i) a non-ferromagnetic portion having a surface that is in contact with a second surface of the second dielectric, and (ii) a second portion having at least one ferromagnetic material disposed between the non-ferromagnetic portion of the electrode and the conductor.
    Type: Application
    Filed: August 27, 2019
    Publication date: December 19, 2019
    Applicant: Everspin Technologies, Inc.
    Inventors: Renu WHIG, Jijun SUN, Nicholas RIZZO, Jon SLAUGHTER, Dimitri HOUSSAMEDDINE, Frederick MANCOFF
  • Patent number: 10503593
    Abstract: In some examples, a memory device may be configured to provide quad bit error correction circuits. For example, the memory device may be equipped with a two layer error correction circuit. In some cases, the first layer may utilized one or more Hamming coders and the second layer may utilize one or Golay coders. In some examples, the Golay coders may be grouped into sets of Golay coders.
    Type: Grant
    Filed: September 7, 2018
    Date of Patent: December 10, 2019
    Assignee: Everspin Technologies, Inc.
    Inventor: Kurt Baty
  • Publication number: 20190355897
    Abstract: A magnetoresistive device with a magnetically fixed region having at least two ferromagnetic regions coupled together by an antiferromagnetic coupling region. At least one of the two ferromagnetic regions includes multiple alternating metal layers and magnetic layers and one or more interfacial layers. Wherein, each metal layer includes at least one of platinum, palladium, nickel, or gold, and the interfacial layers include at least one of an oxide, iron, or an alloy including cobalt and iron.
    Type: Application
    Filed: May 14, 2019
    Publication date: November 21, 2019
    Applicant: Everspin Technologies, Inc.
    Inventor: Jijun SUN
  • Publication number: 20190355398
    Abstract: In some examples, a memory device may have at least a first and a second memory array. In some cases, a portion of the bit cells of the first memory array may be coupled to first PMOS-follower circuitry and to second PMOS-follower circuitry. A portions of the bit cells of the second memory array may also be coupled to the second PMOS-follower circuitry and to third PMOS-follower circuitry. Additionally, in some cases, the portion of bit cells of both the first memory array and the second memory array may be coupled to shared preamplifier circuitry.
    Type: Application
    Filed: July 22, 2019
    Publication date: November 21, 2019
    Applicant: Everspin Technologies, Inc.
    Inventors: Syed M. ALAM, Thomas S. ANDRE
  • Patent number: 10483320
    Abstract: A magnetoresistive stack/structure and method of manufacturing same comprising wherein the stack/structure includes a seed region, a fixed magnetic region disposed on and in contact with the seed region, a dielectric layer(s) disposed on the fixed magnetic region and a free magnetic region disposed on the dielectric layer(s). In one embodiment, the seed region comprises an alloy including nickel and chromium having (i) a thickness greater than or equal to 40 Angstroms (+/?10%) and less than or equal to 60 Angstroms (+/?10%), and (ii) a material composition or content of chromium within a range of 25-60 atomic percent (+/?10%) or 30-50 atomic percent (+/?10%).
    Type: Grant
    Filed: November 19, 2018
    Date of Patent: November 19, 2019
    Assignee: Everspin Technologies, Inc.
    Inventors: Jijun Sun, Sanjeev Aggarwal, Han-Jong Chia, Jon M. Slaughter, Renu Whig
  • Patent number: 10483460
    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 the first encapsulation layer which is disposed over the exposed surface of the dielectric layer. The method further includes (a) 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 (b) depositing a third encapsulation layer: (i) on the second encapsulation layer which is on the first encapsulation layer and the exposed surface of the dielectric layer. The method also includes etching the remaining layers of the stack/structure (via one or more etch processes).
    Type: Grant
    Filed: October 28, 2016
    Date of Patent: November 19, 2019
    Assignee: Everspin Technologies, Inc.
    Inventors: Kerry Joseph Nagel, Wenchin Lin, Sarin A. Deshpande, Jijun Sun, Sanjeev Aggarwal, Chaitanya Mudivarthi
  • Patent number: 10475986
    Abstract: A magnetoresistive device includes first and second ferromagnetic regions and an intermediate region formed of a dielectric material between the first and second ferromagnetic regions. A surface of the intermediate region at an interface between the intermediate region and at least one of the first and second ferromagnetic regions may be a plasma treated surface.
    Type: Grant
    Filed: April 19, 2018
    Date of Patent: November 12, 2019
    Assignee: EVERSPIN TECHNOLOGIES, INC.
    Inventor: Jijun Sun
  • Patent number: 10475497
    Abstract: Precharging circuits and techniques are presented for use with magnetic memory devices in order to speed up access to the memory cells for reading and writing. Including precharging in the sense amplifiers used to access the memory cells enables self-referenced read operations to be completed more quickly than is possible without precharging. Similarly, precharging can also be used in conjunction with write-back operations in order to allow the data state stored by magnetic tunnel junctions included in the memory cells to be changed more rapidly.
    Type: Grant
    Filed: June 5, 2018
    Date of Patent: November 12, 2019
    Assignee: Everspin Technologies, Inc.
    Inventors: Syed M. Alam, Chitra Subramanian
  • Publication number: 20190334082
    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, after patterning the mask, etching (a) through a first layer of electrically conductive material to form an electrically conductive electrode and (b) through a third layer of ferromagnetic material to provide sidewalls of the second synthetic antiferromagnetic structure. The process further includes providing insulating material on or over the sidewalls of the second synthetic antiferromagnetic structure and, thereafter, etching through (a) a second tunnel barrier layer to provide sidewalls thereof, (b) a second layer of ferromagnetic material to provide sidewalls thereof, (c) a first tunnel barrier layer to provide sidewalls thereof, and (d) a first layer of ferromagnetic material to provide sidewalls of the first synthetic antiferromagnetic structure.
    Type: Application
    Filed: July 11, 2019
    Publication date: October 31, 2019
    Applicant: Everspin Technologies, Inc.
    Inventors: Sarin A. DESHPANDE, Sanjeev AGGARWAL, Kerry Joseph NAGEL
  • Patent number: 10461243
    Abstract: Techniques for configuring the layers included in the free portion of a spin-torque magnetoresistive device are presented that allow for characteristics of the free portion to be tuned to meet the needs of various applications. In one embodiment, high data retention is achieved by balancing the perpendicular magnetic anisotropy of the ferromagnetic layers in the free portion. In other embodiments, imbalanced ferromagnetic layers provide for lower switching current for the magnetoresistive device. In various embodiments, different coupling layers can be used to provide exchange coupling between the ferromagnetic layers in the free portion, including oscillatory coupling layers, ferromagnetic coupling layers using materials that can alloy with the neighboring ferromagnetic layers, and discontinuous layers of dielectric material such as MgO that result in limited coupling between the ferromagnetic layers and increases perpendicular magnetic anisotropy (PMA) at the interface with those layers.
    Type: Grant
    Filed: February 5, 2018
    Date of Patent: October 29, 2019
    Assignee: Everspin Technologies, Inc.
    Inventors: Han-Jong Chia, Jon Slaughter
  • Patent number: 10461251
    Abstract: A method of fabricating a magnetoresistive bit from a magnetoresistive stack includes etching through a first portion of the magnetoresistive stack using a first etch process to form one or more sidewalls. At least a portion of the sidewalls includes redeposited material after the etching. The method also includes modifying at least a portion of the redeposited material on the sidewalls, and etching through a second portion of the magnetoresistive stack after the modifying step. The magnetoresistive stack may include a first magnetic region, an intermediate region disposed over the first magnetic region, and a second magnetic region disposed over the intermediate region.
    Type: Grant
    Filed: August 21, 2018
    Date of Patent: October 29, 2019
    Assignee: EVERSPIN TECHNOLOGIES, INC.
    Inventors: Sanjeev Aggarwal, Sarin A. Deshpande, Kerry Joseph Nagel
  • Patent number: 10461250
    Abstract: A method of manufacturing a magnetoresistive stack/structure comprising (a) etching through a second magnetic region to (i) provide sidewalls of the second magnetic region and (ii) expose a surface of a dielectric layer, (b) depositing a first encapsulation layer on the sidewalls of the second magnetic region and over a surface of the dielectric layer, (c) thereafter: (i) etching the first encapsulation layer which is disposed over the dielectric layer using a first etch process, and (ii) etching re-deposited material using a second etch process, wherein, after such etching, a portion of the first encapsulation layer remains on the sidewalls of the second magnetic region, (d) etching (i) through the dielectric layer to form a tunnel barrier and provide sidewalls thereof and (ii) etching the first magnetic region to provide sidewalls thereof, and (e) depositing a second encapsulation layer on the sidewalls of the tunnel barrier and first magnetic region.
    Type: Grant
    Filed: July 31, 2018
    Date of Patent: October 29, 2019
    Assignee: EVERSPIN TECHNOLOGIES, INC.
    Inventors: Sarin A. Deshpande, Kerry Joseph Nagel, Chaitanya Mudivarthi, Sanjeev Aggarwal
  • Publication number: 20190326506
    Abstract: A magnetoresistive device includes first and second ferromagnetic regions and an intermediate region formed of a dielectric material between the first and second ferromagnetic regions. A surface of the intermediate region at an interface between the intermediate region and at least one of the first and second ferromagnetic regions may be a plasma treated surface.
    Type: Application
    Filed: April 19, 2018
    Publication date: October 24, 2019
    Applicant: Everspin Technologies, Inc.
    Inventor: Jijun SUN
  • Patent number: 10446213
    Abstract: The present disclosure is drawn to, among other things, a magnetoresistive memory. The magnetoresistive memory includes a first memory cell, a first access circuit, a second access circuit, and a current generating circuit. The first memory cell includes a first magnetic tunnel junction and a second magnetic tunnel junction. The first access circuit is configured to receive access command signals for accessing the first magnetic tunnel junction. The first access circuit includes a first access switch and a second access switch. The second access circuit is configured to receive access command signals for accessing the second magnetic tunnel junction. The second access circuit includes a third access switch and a fourth access switch. The current generating circuit is configured to generate a first write current through the first magnetic tunnel junction and generate a second write current through the second magnetic tunnel junction based on data input signals.
    Type: Grant
    Filed: May 16, 2018
    Date of Patent: October 15, 2019
    Assignee: Everspin Technologies, Inc.
    Inventors: Yaojun Zhang, Syed M. Alam, Thomas Andre
  • Publication number: 20190312198
    Abstract: Spin-orbit-torque (SOT) lines are provided near free regions in magnetoresistive devices that include magnetic tunnel junctions. Current flowing through such SOT lines injects spin current into the free regions such that spin torque is applied to the free regions. The spin torque generated from a SOT switching line can be used to switching the free region or to act as an assist to spin-transfer torque generated by current flowing vertically through the magnetic tunnel junction, in order to improve the reliability, endurance, or both of the magnetoresistive device. Further, one or more additional layers or regions may improve the SOT switching efficiency and the thermal stability of magnetoresistive devices including SOT lines.
    Type: Application
    Filed: April 5, 2019
    Publication date: October 10, 2019
    Applicant: Everspin Technologies, Inc.
    Inventor: Jijun SUN
  • Publication number: 20190305213
    Abstract: A magnetoresistive device may include a tunnel barrier region, a magnetically fixed region positioned on one side of the tunnel barrier region, and a magnetically free region positioned on an opposite side of the tunnel barrier region. The magnetically free region may include a plurality of ferromagnetic regions and at least one nonmagnetic insertion region.
    Type: Application
    Filed: March 30, 2018
    Publication date: October 3, 2019
    Applicant: Everspin Technologies, Inc.
    Inventor: Jijun Sun
  • Publication number: 20190280198
    Abstract: A magnetoresistive element (e.g., a spin-torque magnetoresistive memory element) includes a fixed magnetic layer, a free magnetic layer, having a high-iron alloy interface region located along a surface of the free magnetic layer, wherein the high-iron alloy interface region has at least 50% iron by atomic composition, and a first dielectric, disposed between the fixed magnetic layer and the free magnetic layer. The magnetoresistive element further includes a second dielectric, having a first surface that is in contact with the surface of the free magnetic layer, and an electrode, disposed between the second dielectric and a conductor. The electrode includes: (i) a non-ferromagnetic portion having a surface that is in contact with a second surface of the second dielectric, and (ii) a second portion having at least one ferromagnetic material disposed between the non-ferromagnetic portion of the electrode and the conductor.
    Type: Application
    Filed: May 22, 2019
    Publication date: September 12, 2019
    Applicant: EVERSPIN TECHNOLOGIES, INC.
    Inventors: Renu WHIG, Jijun SUN, Nicholas RIZZO, Jon SLAUGHTER, Dimitri HOUSSAMEDDINE, Frederick MANCOFF
  • Publication number: 20190280045
    Abstract: A magnetoresistive device may include an annular-shaped magnetic tunnel junction (MTJ) bit having an inner end and an outer end. The MTJ bit may include an annular-shaped magnetically free region and an annular-shaped magnetically fixed region separated by an annular-shaped intermediate layer. A first electrical conductor may be in electrical contact with the inner end of the MTJ bit, and a second electrical conductor may be in electrical contact with the outer end of the MTJ bit.
    Type: Application
    Filed: March 6, 2019
    Publication date: September 12, 2019
    Applicant: Everspin Technologies, Inc.
    Inventors: Sanjeev AGGARWAL, Kevin Conley, Sarin A. Deshpande
  • Patent number: 10395699
    Abstract: In some examples, a memory device may have at least a first and a second memory array. In some cases, a portion of the bit cells of the first memory array may be coupled to first PMOS-follower circuitry and to second PMOS-follower circuitry. A portion of the bit cells of the second memory array may also be coupled to the second PMOS-follower circuitry and to third PMOS-follower circuitry. Additionally, in some cases, the portions of bit cells of both the first memory array and the second memory array may be coupled to shared preamplifier circuitry.
    Type: Grant
    Filed: September 25, 2014
    Date of Patent: August 27, 2019
    Assignee: Everspin Technologies, Inc.
    Inventors: Syed M. Alam, Thomas Andre