Patents by Inventor Patrick Mesquita Braganca

Patrick Mesquita Braganca 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: 20180061887
    Abstract: An MRAM cell having an MTJ stack with a free layer and an interconnect configured to generate a spin current and a magnetic field effect that is used to affect the magnetic moment of the free layer. The interconnect may comprise a Spin Hall lead. The interconnect may comprise an antiferromagnetic material. An MRAM cell array may include a plurality of bit elements each configured to store at least one bit, an interconnect coupled to the plurality of bit elements, and a transistor formed at a periphery of the MRAM cell array and configured to supply a current to the plurality of bit elements via the interconnect. The interconnect may be configured to generate a spin current and a magnetic field effect that is used to affect the magnetic moment of the free layer of each of the plurality of bit elements.
    Type: Application
    Filed: August 25, 2016
    Publication date: March 1, 2018
    Inventor: Patrick Mesquita Braganca
  • Patent number: 9236069
    Abstract: A method for making a current-perpendicular-to-the-plane magnetoresistive sensor structure produces a top electrode that is “self-aligned” on the top of the sensor and with a width less than the sensor trackwidth. A pair of walls of ion-milling resistant material are fabricated to a predetermined height above the biasing layers at the sensor side edges. A layer of electrode material is then deposited onto the top of the sensor between the two walls. The walls serve as a mask during angled ion milling to remove outer portions of the electrode layer. The height of the walls and the angle of ion milling determines the width of the resulting top electrode. This leaves the reduced-width top electrode located on the sensor. Because of the directional ion milling using walls that are aligned with the sensor side edges, the reduced-width top electrode is self-aligned in the center of the sensor.
    Type: Grant
    Filed: March 29, 2013
    Date of Patent: January 12, 2016
    Assignee: HGST Netherlands B.V.
    Inventors: Patrick Mesquita Braganca, Jeffrey R. Childress, Jordan Asher Katine, Yang Li, Neil Leslie Robertson, Neil Smith, Petrus Antonius VanDerHeijden, Douglas Johnson Werner
  • Patent number: 9218831
    Abstract: A side-by-side magnetic multi-input multi-output (MIMO) read head is provided. The read head may include a pair of side-by-side MIMO read sensors disposed between a bottom shield, a top shield and between a pair of side shields. The read head may also include a pair of electrical leads, each of which is coupled with one of the MIMO read sensors. The electrical leads extend away from an air bearing surface.
    Type: Grant
    Filed: September 17, 2014
    Date of Patent: December 22, 2015
    Assignee: HGST Netherlands B.V.
    Inventors: Patrick Mesquita Braganca, Jordan Asher Katine, Hsin-wei Tseng, Howard Gordon Zolla
  • Publication number: 20150147481
    Abstract: A method for making a scissoring type current-perpendicular-to-the-plane magnetoresistive sensor with exchange-coupled soft side shields uses oblique angle ion milling to remove unwanted material from the side edges of the upper free layer. All of the layers making up the sensor stack are deposited as full films. The sensor stack is then ion milled to define the sensor side edges. The side regions are then refilled by deposition of an insulating layer. Next, the lower soft magnetic layers of the exchange-coupled side shields are deposited, which also coats the insulating layer up to and past the side edges of the upper free layer. The soft magnetic material adjacent the side edges of the upper free layer is removed by oblique angle ion beam milling. The material for the antiparallel-coupling (APC) layers is deposited, followed by deposition of the material for the upper soft magnetic layers of the exchange-coupled side shields.
    Type: Application
    Filed: November 20, 2013
    Publication date: May 28, 2015
    Applicant: HGST Nertherlands B..V.
    Inventors: Patrick Mesquita Braganca, Jordan Asher Katine, Neil Smith
  • Patent number: 8988833
    Abstract: A current-perpendicular-to-the plane magnetoresistive sensor has top and bottom electrodes narrower than the sensor trackwidth. The electrodes are formed of one of Cu, Au, Ag and AgSn, which have an ion milling etch rate much higher than the etch rates for the sensor's ferromagnetic materials. Ion milling is performed at a high angle relative to a line orthogonal to the plane of the electrode layers and the layers in the sensor stack. Because of the much higher etch rate of the material of the top and bottom electrode layers, the electrode layers will have side edges that are recessed from the side edges of the free layer. This reduces the surface areas for the top and bottom electrodes, which causes the sense current passing through the sensor's free layer to be confined in a narrower channel, which is equivalent to having a sensor with narrower physical trackwidth.
    Type: Grant
    Filed: May 16, 2013
    Date of Patent: March 24, 2015
    Assignee: HGST Netherlands B.V.
    Inventors: Patrick Mesquita Braganca, Jeffrey R. Childress, Jordan Asher Katine, Yang Li, Neil Leslie Robertson, Neil Smith, Petrus Antonius VanDerHeijden, Douglas Johnson Werner
  • Publication number: 20140340791
    Abstract: A current-perpendicular-to-the plane magnetoresistive sensor has top and bottom electrodes narrower than the sensor trackwidth. The electrodes are formed of one of Cu, Au, Ag and AgSn, which have an ion milling etch rate much higher than the etch rates for the sensor's ferromagnetic materials. Ion milling is performed at a high angle relative to a line orthogonal to the plane of the electrode layers and the layers in the sensor stack. Because of the much higher etch rate of the material of the top and bottom electrode layers, the electrode layers will have side edges that are recessed from the side edges of the free layer. This reduces the surface areas for the top and bottom electrodes, which causes the sense current passing through the sensor's free layer to be confined in a narrower channel, which is equivalent to having a sensor with narrower physical trackwidth.
    Type: Application
    Filed: May 16, 2013
    Publication date: November 20, 2014
    Applicant: HGST Netherlands B.V.
    Inventors: Patrick Mesquita Braganca, Jeffrey R. Childress, Jordan Asher Katine, Yang Li, Neil Leslie Robertson, Neil Smith, Petrus Antonius VanDerHeijden, Douglas Johnson Werner
  • Publication number: 20140291283
    Abstract: A method for making a current-perpendicular-to-the-plane magnetoresistive sensor structure produces a top electrode that is “self-aligned” on the top of the sensor and with a width less than the sensor trackwidth. A pair of walls of ion-milling resistant material are fabricated to a predetermined height above the biasing layers at the sensor side edges. A layer of electrode material is then deposited onto the top of the sensor between the two walls. The walls serve as a mask during angled ion milling to remove outer portions of the electrode layer. The height of the walls and the angle of ion milling determines the width of the resulting top electrode. This leaves the reduced-width top electrode located on the sensor. Because of the directional ion milling using walls that are aligned with the sensor side edges, the reduced-width top electrode is self-aligned in the center of the sensor.
    Type: Application
    Filed: March 29, 2013
    Publication date: October 2, 2014
    Applicant: HGST Netherlands B.V.
    Inventors: Patrick Mesquita Braganca, Jeffrey R. Childress, Jordan Asher Katine, Yang Li, Neil Leslie Robertson, Neil Smith, Petrus Antonius VanDerHeijden, Douglas Johnson Werner
  • Patent number: 8675309
    Abstract: A spin-torque oscillator with antiferromagnetically-coupled free layers has at least one of the free layers with increased magnetic damping. The Gilbert magnetic damping parameter (?) is at least 0.05. The damped free layer may contain as a dopant one or more damping elements selected from the group consisting of Pt, Pd and the 15 lanthanide elements. The free layer damping may also be increased by a damping layer adjacent the free layer. One type of damping layer may be an antiferromagnetic material, like a Mn alloy. As a modification to the antiferromagnetic damping layer, a bilayer damping layer may be formed of the antiferromagnetic layer and a nonmagnetic metal electrically conductive separation layer between the free layer and the antiferromagnetic layer. Another type of damping layer may be one formed of one or more of the elements selected from Pt, Pd and the lanthanides.
    Type: Grant
    Filed: April 6, 2013
    Date of Patent: March 18, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Patrick Mesquita Braganca, Bruce Alvin Gurney
  • Patent number: 8670217
    Abstract: A scissoring-type CPP-MR sensor has the two free ferromagnetic layers formed as exchange-coupled structures. Each exchange-coupled structure includes a patterned layer formed of alternating stripes of ferromagnetic stripes and nonmagnetic stripes, and a continuous unpatterned ferromagnetic layer in contact with and exchange-coupled to the ferromagnetic stripes of the patterned layer. The ferromagnetic stripes have a length-to-width aspect ratio of at least 2, which results in increased uniaxial anisotropy of the exchange-coupled unpatterned ferromagnetic layer. The stripes are oriented at an acute angle relative to the disk-facing surface of the sensor, and the stripes of the first free layer are generally orthogonal to the stripes of the second free layers. A hard magnet layer is magnetized in a direction orthogonal to the disk-facing surface for biasing the magnetization directions of the unpatterned ferromagnetic layers in the first and second free layers generally orthogonal to one another.
    Type: Grant
    Filed: February 11, 2013
    Date of Patent: March 11, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Patrick Mesquita Braganca, Jeffrey R. Childress, Yang Li, Neil Smith
  • Patent number: 8670216
    Abstract: A current-perpendicular-to-the-plane (CPP) magnetoresistive (MR) sensor has a reference layer formed as an exchange-coupled structure. The exchange-coupled structure includes a patterned layer formed of alternating stripes of ferromagnetic stripes and nonmagnetic stripes, and a continuous unpatterned ferromagnetic layer in contact with and exchange-coupled to the ferromagnetic stripes of the patterned layer. The ferromagnetic stripes have a length-to-width aspect ratio of at least 2, which results in increased uniaxial anisotropy of the exchange-coupled ferromagnetic layer.
    Type: Grant
    Filed: February 11, 2013
    Date of Patent: March 11, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Patrick Mesquita Braganca, Jeffrey R. Childress, Yang Li, Neil Smith
  • Patent number: 8654465
    Abstract: A method, apparatus, and system are provided for implementing spin-torque oscillator (STO) sensing with a demodulator for hard disk drives. The demodulator measures an instantaneous phase of the readback signal from a STO sensor and converts the readback signal into a signal that is proportional to the magnetic field affecting the STO frequency during a bit time. The converted signal is used for processing by conventional data detection electronics.
    Type: Grant
    Filed: December 9, 2011
    Date of Patent: February 18, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Patrick Mesquita Braganca, Richard Leo Galbraith, Bruce Alvin Gurney, Neil Smith, Bruce Wilson, Rehan Ahmed Zakai
  • Patent number: 8570677
    Abstract: A method, apparatus, and system are provided for implementing spin-torque oscillator sensing with an enhanced integrated demodulator for hard disk drives. The demodulator receives an input signal from a STO read sensor having an oscillation frequency ? related to the strength of the detected magnetic signal field. The demodulator includes a pair of mixers coupled to a quadrature reference oscillator with respective quadrature components cos(?0t), and sin(?0t) of the quadrature reference oscillator being mixed with a received input signal to form signals at the sum and difference frequencies, ?±?0. Each of these mixer products is lowpass filtered by a respective a lowpass filter to remove the sum frequency components for providing a demodulator output signal that is directly proportional the STO oscillation frequency ?. The demodulator output signal is used for processing by data detection electronics.
    Type: Grant
    Filed: December 9, 2011
    Date of Patent: October 29, 2013
    Assignee: HGST Netherlands B.V.
    Inventors: Patrick Mesquita Braganca, Richard Leo Galbraith, Bruce Alvin Gurney, Neil Smith, Bruce Wilson, Rehan Ahmed Zakai
  • Patent number: 8553346
    Abstract: A method, apparatus, and system for implementing spin-torque oscillator (STO) sensing with an enhanced delay control feedback circuit for hard disk drives. A detector receives an input signal from a STO read sensor having an oscillation frequency related to the strength of the detected magnetic signal field. The received input signal is mixed with a time delayed input signal for providing a detector output signal. A low frequency component signal of the detector output signal is monitored and a delay control feedback is applied to an adjustable time delay to bias the DC signal of the detector output signal.
    Type: Grant
    Filed: December 9, 2011
    Date of Patent: October 8, 2013
    Assignee: HGST Netherlands B.V.
    Inventors: Patrick Mesquita Braganca, Richard Leo Galbraith, Bruce Alvin Gurney, Neil Smith, Bruce Wilson, Rehan Ahmed Zakai
  • Publication number: 20130148224
    Abstract: A method, apparatus, and system are provided for implementing spin-torque oscillator sensing with an enhanced integrated demodulator for hard disk drives. The demodulator receives an input signal from a STO read sensor having an oscillation frequency ? related to the strength of the detected magnetic signal field. The demodulator includes a pair of mixers coupled to a quadrature reference oscillator with respective quadrature components cos(?0t), and sin(?0t) of the quadrature reference oscillator being mixed with a received input signal to form signals at the sum and difference frequencies, ?±?0. Each of these mixer products is lowpass filtered by a respective a lowpass filter to remove the sum frequency components for providing a demodulator output signal that is directly proportional the STO oscillation frequency ?. The demodulator output signal is used for processing by data detection electronics.
    Type: Application
    Filed: December 9, 2011
    Publication date: June 13, 2013
    Applicant: Hitachi Global Storage Technologies Netherlands. B.V.
    Inventors: Patrick Mesquita Braganca, Richard Leo Galbraith, Bruce Alvin Gurney, Neil Smith, Bruce Wilson, Rehan Ahmed Zakai
  • Publication number: 20130148223
    Abstract: A method, apparatus, and system are provided for implementing spin-torque oscillator (STO) sensing with a demodulator for hard disk drives. The demodulator measures an instantaneous phase of the readback signal from a STO sensor and converts the readback signal into a signal that is proportional to the magnetic field affecting the STO frequency during a bit time. The converted signal is used for processing by conventional data detection electronics.
    Type: Application
    Filed: December 9, 2011
    Publication date: June 13, 2013
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Patrick Mesquita Braganca, Richard Leo Galbraith, Bruce Alvin Gurney, Neil Smith, Bruce Wilson, Rehan Ahmed Zakai
  • Publication number: 20130148229
    Abstract: A method, apparatus, and system for implementing spin-torque oscillator (STO) sensing with an enhanced delay control feedback circuit for hard disk drives. A detector receives an input signal from a STO read sensor having an oscillation frequency related to the strength of the detected magnetic signal field. The received input signal is mixed with a time delayed input signal for providing a detector output signal. A low frequency component signal of the detector output signal is monitored and a delay control feedback is applied to an adjustable time delay to bias the DC signal of the detector output signal.
    Type: Application
    Filed: December 9, 2011
    Publication date: June 13, 2013
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Patrick Mesquita Braganca, Richard Leo Galbraith, Bruce Alvin Gurney, Neil Smith, Bruce Wilson, Rehan Ahmed Zakai
  • Patent number: 8462461
    Abstract: A spin-torque oscillator (STO) has increased magnetic damping of the oscillating free ferromagnetic layer. The Gilbert magnetic damping parameter (?) is at least 0.05, and preferably greater than 0.05. The free layer may be a any type of conventional ferromagnetic material, but contains one or more damping elements as a dopant. The damping element is selected from the group consisting of Pt, Pd and the 15 lanthanide elements. The free layer damping may also be increased by a damping layer adjacent the free layer. One type of damping layer may be an antiferromagnetic material, like a Mn alloy. As a modification to the antiferromagnetic damping layer, a bilayer damping layer may be formed of the antiferromagnetic layer and a nonmagnetic metal electrically conductive separation layer between the free layer and the antiferromagnetic layer. Another type of damping layer may be one formed of one or more of the elements selected from Pt, Pd and the lanthanides.
    Type: Grant
    Filed: July 5, 2011
    Date of Patent: June 11, 2013
    Assignee: HGST Netherlands B.V.
    Inventors: Patrick Mesquita Braganca, Bruce Alvin Gurney
  • Publication number: 20130063841
    Abstract: A “thermagnonic” spin-torque oscillator (STO) uses heat flow alone to cause the spin-torque (ST) effect and generate the persistent oscillation of the free layer magnetization. In addition to the conventional free and reference layers, the thermagnonic STO also includes a magnetic oxide layer having a fixed in-plane magnetization, a ferromagnetic metallic layer on one surface of the magnetic oxide layer, a nonmagnetic electrically conductive layer between the free layer and the metallic layer, and an electrically resistive heater on the other surface of the magnetic oxide layer. Due to the thermagnonic effect, heat flow from the magnetic oxide layer through the metallic layer, conductive layer and free layer ultimately results in a spin transfer torque (STT) to the free layer. Electrical sense current flowing in the opposite direction as the heat flow is used to monitor the frequency of oscillation of the free layer magnetization.
    Type: Application
    Filed: September 8, 2011
    Publication date: March 14, 2013
    Inventors: Patrick Mesquita Braganca, Bruce Alvin Gurney
  • Patent number: 8379352
    Abstract: A “thermagnonic” spin-torque oscillator (STO) uses heat flow alone to cause the spin-torque (ST) effect and generate the persistent oscillation of the free layer magnetization. In addition to the conventional free and reference layers, the thermagnonic STO also includes a magnetic oxide layer having a fixed in-plane magnetization, a ferromagnetic metallic layer on one surface of the magnetic oxide layer, a nonmagnetic electrically conductive layer between the free layer and the metallic layer, and an electrically resistive heater on the other surface of the magnetic oxide layer. Due to the thermagnonic effect, heat flow from the magnetic oxide layer through the metallic layer, conductive layer and free layer ultimately results in a spin transfer torque (STT) to the free layer. Electrical sense current flowing in the opposite direction as the heat flow is used to monitor the frequency of oscillation of the free layer magnetization.
    Type: Grant
    Filed: September 8, 2011
    Date of Patent: February 19, 2013
    Assignee: HGST Netherlands B.V.
    Inventors: Patrick Mesquita Braganca, Bruce Alvin Gurney
  • Publication number: 20130009712
    Abstract: A spin-torque oscillator (STO) has increased magnetic damping of the oscillating free ferromagnetic layer. The Gilbert magnetic damping parameter (a) is at least 0.05, and preferably greater than 0.05. The free layer may be a any type of conventional ferromagnetic material, but contains one or more damping elements as a dopant. The damping element is selected from the group consisting of Pt, Pd and the 15 lanthanide elements. The free layer damping may also be increased by a damping layer adjacent the free layer. One type of damping layer may be an antiferromagnetic material, like a Mn alloy. As a modification to the antiferromagnetic damping layer, a bilayer damping layer may be formed of the antiferromagnetic layer and a nonmagnetic metal electrically conductive separation layer between the free layer and the antiferromagnetic layer. Another type of damping layer may be one formed of one or more of the elements selected from Pt, Pd and the lanthanides.
    Type: Application
    Filed: July 5, 2011
    Publication date: January 10, 2013
    Inventors: Patrick Mesquita Braganca, Bruce Alvin Gurney