Patents by Inventor Stuart Parkin

Stuart Parkin 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: 20170338403
    Abstract: Example embodiments relate to magnetic memory devices and methods for manufacturing the same. The magnetic memory device includes a magnetic tunnel junction layer including a first magnetic layer, a second magnetic layer, and a first tunnel barrier layer between the first and second magnetic layers. The second magnetic layer is disposed on the first tunnel barrier layer and is in direct contact with the first tunnel barrier layer. The second magnetic layer includes cobalt-iron-beryllium (CoFeBe). A beryllium content of CoFeBe in the second magnetic layer ranges from about 2 at % to about 15 at %.
    Type: Application
    Filed: November 23, 2016
    Publication date: November 23, 2017
    Applicants: Samsung Electronics Co., Ltd., International Business Machines Corporation
    Inventors: Woojin KIM, Keewon KIM, S.P. Stuart PARKIN, Jaewoo JEONG, Mahesh Govind SAMANT
  • Patent number: 9825217
    Abstract: Example embodiments relate to magnetic memory devices and methods for manufacturing the same. The magnetic memory device includes a magnetic tunnel junction layer including a first magnetic layer, a second magnetic layer, and a first tunnel barrier layer between the first and second magnetic layers. The second magnetic layer is disposed on the first tunnel barrier layer and is in direct contact with the first tunnel barrier layer. The second magnetic layer includes cobalt-iron-beryllium (CoFeBe). A beryllium content of CoFeBe in the second magnetic layer ranges from about 2 at % to about 15 at %.
    Type: Grant
    Filed: November 23, 2016
    Date of Patent: November 21, 2017
    Assignees: Samsung Electronics Co., Ltd., International Business Machines Corporation
    Inventors: Woojin Kim, Keewon Kim, S. P. Stuart Parkin, Jaewoo Jeong, Mahesh Govind Samant
  • Patent number: 7760535
    Abstract: A method and structure for depinning a domain wall that is in spatial confinement by a pinning potential to within a local region of a magnetic device. At least one current pulse applied to the domain has a pulse length sufficiently close to a precession period of the domain wall motion and the current pulses are separated by a pulse interval sufficiently close to the precession period such that: the at least one current pulse causes a depinning of the domain wall such that the domain wall escapes the spatial confinement; and each current pulse has an amplitude less than the minimum amplitude of a direct current that would cause the depinning if the direct current were applied to the domain wall instead of the at least one current pulse. The pulse length and pulse interval may be in a range of 25% to 75% of the precession period.
    Type: Grant
    Filed: May 21, 2008
    Date of Patent: July 20, 2010
    Assignee: International Business Machines Corporation
    Inventors: Stuart Parkin, Luc Thomas
  • Publication number: 20100046268
    Abstract: A method for use with a magnetic racetrack device includes placing domain walls having a first structure and domain walls having a second, different structure along the racetrack at stable positions corresponding to different regions within the device. The domain walls having the first structure and the domain walls having the second structure occupy alternating positions along the racetrack. A current pulse is applied to the racetrack, so that each of the domain walls moves to an adjacent region. This results in a transformation of the domain walls having the first structure into domain walls having the second structure, and vice versa. The first structure may be a vortex structure and the second structure may be a transverse structure.
    Type: Application
    Filed: September 2, 2009
    Publication date: February 25, 2010
    Applicant: International Business Machines Corporation
    Inventors: Rai Moriya, Stuart Parkin, Luc Thomas
  • Patent number: 7667994
    Abstract: A method for use with a magnetic racetrack device includes placing domain walls having a first structure and domain walls having a second, different structure along the racetrack at stable positions corresponding to different regions within the device. The domain walls having the first structure and the domain walls having the second structure occupy alternating positions along the racetrack. A current pulse is applied to the racetrack, so that each of the domain walls moves to an adjacent region. This results in a transformation of the domain walls having the first structure into domain walls having the second structure, and vice versa. The first structure may be a vortex structure and the second structure may be a transverse structure.
    Type: Grant
    Filed: September 2, 2009
    Date of Patent: February 23, 2010
    Assignee: International Business Machines Corporation
    Inventors: Rai Moriya, Stuart Parkin, Luc Thomas
  • Patent number: 7626844
    Abstract: A racetrack memory device facilitates the manipulation of a series of domain walls along the racetrack. The racetrack is designed so that the domain wall energy increases and decreases in a continuous fashion between adjacent pinning sites, so that a domain wall does not become stuck between them. The variation in the domain wall energy along the racetrack can be provided by continuous variations of the racetrack's width (while maintaining constant thickness) and/or cross-sectional area (in which the racetrack dimensions are varied in both directions perpendicular to the length of the racetrack). Alternatively, this variation in domain wall energy may be provided by varying the magnetic properties of the racetrack along the racetrack while otherwise keeping the shape and size of the racetrack unchanged. In addition, variations of the racetrack's composition and/or shape can be used.
    Type: Grant
    Filed: August 22, 2008
    Date of Patent: December 1, 2009
    Assignee: International Business Machines Corporation
    Inventors: Rai Moriya, Stuart Parkin, Luc Thomas
  • Publication number: 20090103347
    Abstract: A method and structure for depinning a domain wall that is in spatial confinement by a pinning potential to within a local region of a magnetic device. At least one current pulse applied to the domain has a pulse length sufficiently close to a precession period of the domain wall motion and the current pulses are separated by a pulse interval sufficiently close to the precession period such that: the at least one current pulse causes a depinning of the domain wall such that the domain wall escapes the spatial confinement; and each current pulse has an amplitude less than the minimum amplitude of a direct current that would cause the depinning if the direct current were applied to the domain wall instead of the at least one current pulse. The pulse length and pulse interval may be in a range of 25% to 75% of the precession period.
    Type: Application
    Filed: May 21, 2008
    Publication date: April 23, 2009
    Inventors: Stuart Parkin, Luc Thomas
  • Patent number: 7492622
    Abstract: A method and structure for depinning a domain wall that is in spatial confinement by a pinning potential to within a local region of a magnetic device. At least one current pulse applied to the domain has a pulse length sufficiently close to a precession period of the domain wall motion and the current pulses are separated by a pulse interval sufficiently close to the precession period such that: the at least one current pulse causes a depinning of the domain wall such that the domain wall escapes the spatial confinement; and each current pulse has an amplitude less than the minimum amplitude of a direct current that would cause the depinning if the direct current were applied to the domain wall instead of the at least one current pulse. The pulse length and pulse interval may be in a range of 25% to 75% of the precession period.
    Type: Grant
    Filed: January 12, 2007
    Date of Patent: February 17, 2009
    Assignee: International Business Machines Corporation
    Inventors: Stuart Parkin, Luc Thomas
  • Publication number: 20080253161
    Abstract: A method and structure for depinning a domain wall that is in spatial confinement by a pinning potential to within a local region of a magnetic device. At least one current pulse applied to the domain has a pulse length sufficiently close to a precession period of the domain wall motion and the current pulses are separated by a pulse interval sufficiently close to the precession period such that: the at least one current pulse causes a depinning of the domain wall such that the domain wall escapes the spatial confinement; and each current pulse has an amplitude less than the minimum amplitude of a direct current that would cause the depinning if the direct current were applied to the domain wall instead of the at least one current pulse. The pulse length and pulse interval may be in a range of 25% to 75% of the precession period.
    Type: Application
    Filed: January 12, 2007
    Publication date: October 16, 2008
    Inventors: Stuart Parkin, Luc Thomas
  • Publication number: 20080025082
    Abstract: A spin-current switchable magnetic memory element (and method of fabricating the memory element) includes a plurality of magnetic layers having a perpendicular magnetic anisotropy component, at least one of the plurality of magnetic layers including an alloy of a rare-earth metal and a transition metal, and at least one barrier layer formed adjacent to at least one of the plurality of magnetic layers.
    Type: Application
    Filed: October 9, 2007
    Publication date: January 31, 2008
    Inventors: Jonathan Sun, Stuart Parkin
  • Publication number: 20070297218
    Abstract: A semiconductor device formed between a wordline and a bitline comprises a growth layer, an antiferromagnetic layer formed on the growth layer, a pinned layer formed on the antiferromagnetic layer, a tunnel barrier layer formed on the pinned layer, and a free layer formed on the tunnel barrier. The wordline and bitline are arranged substantially orthogonal to one another. The growth layer, in turn, comprises tantalum and has a thickness greater than about 75 Angstroms. Moreover, the pinned layer comprises one or more pinned ferromagnetic sublayers. The tunnel barrier comprises magnesium oxide. Finally, the free layer comprises two or more free ferromagnetic sublayers, each free ferromagnetic sublayer having a magnetic anisotropy axis that is oriented about 45 degrees from the wordline and bitline. The semiconductor device may comprise, for example, a magnetic tunnel junction for use in magnetoresistive random access memory (MRAM) circuitry.
    Type: Application
    Filed: June 14, 2006
    Publication date: December 27, 2007
    Applicant: International Business Machines Corporation
    Inventors: David Abraham, Stephen Brown, Stuart Parkin, Daniel Worledge
  • Publication number: 20070087454
    Abstract: A magnetic data track used in a magnetic shift register memory system may be fabricated by forming a multilayered stack of alternating dielectric and/ or silicon layers. A trench is etched in the multi-layer stack structure. A selective etching process is used to corrugate the walls of trench. A seed layer is applied to the walls and bottom of the trench; the seed layer is covered with a magnetic layer. The trench is filled with an insulating material. A patterned layer is applied and portions of insulating material exposed by the pattern are removed, forming holes. Magnetic material and seed layer exposed in holes is selectively removed. The holes are filled with insulating material and connecting leads are attached to data tracks.
    Type: Application
    Filed: October 17, 2005
    Publication date: April 19, 2007
    Inventors: Tze-chiang Chen, Stuart Parkin
  • Publication number: 20060255383
    Abstract: A tunnel barrier in proximity with a layer of a rare earth element-transition metal (RE-TM) alloy forms a device that passes negatively spin-polarized current. The rare earth element includes at least one element selected from the group consisting of Gd, Tb, Dy, Ho, Er, Tm, and Yb. The RE and TM have respective sub-network moments such that the absolute magnitude of the RE sub-network moment is greater than the absolute magnitude of the TM sub-network moment. An additional layer of magnetic material may be used in combination with the tunnel barrier and the RE-TM alloy layer to form a magnetic tunnel junction. Still other layers of tunnel barrier and magnetic material may be used in combination with the foregoing to form a flux-closed double tunnel junction device.
    Type: Application
    Filed: May 16, 2005
    Publication date: November 16, 2006
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Christian Kaiser, Stuart Parkin
  • Publication number: 20060120132
    Abstract: A magnetic shift register utilizes a data column comprising a thin wire of magnetic material. A writing element selectively changes the direction of the magnetic moment in the magnetic domains to write the data to the data column. Associated with each domain wall are large magnetic fringing fields concentrated in a very small space. These magnetic fringing fields write to and read from the magnetic shift register. When the domain wall is moved close to another magnetic material, the fringing fields change the direction of the magnetic moment in the magnetic material, effectively “writing” to the magnetic material. A reading element similar to a tunneling junction comprises a free layer and a pinned layer of magnetic material. Fringing fields change the direction of the magnetic moment in the free layer with respect to the pinned layer, changing electrical resistance of the reading element and “reading” data stored in the magnetic shift register.
    Type: Application
    Filed: December 4, 2004
    Publication date: June 8, 2006
    Applicant: International Business Machines Corporation
    Inventor: Stuart Parkin
  • Publication number: 20060098354
    Abstract: Magnetic tunnel junctions are constructed from a MgO or Mg—ZnO tunnel barrier and amorphous magnetic layers in proximity with, and on respective sides of, the tunnel barrier. The amorphous magnetic layer preferably includes Co and at least one additional element selected to make the layer amorphous, such as boron. Magnetic tunnel junctions formed from the amorphous magnetic layers and the tunnel barrier have tunneling magnetoresistance values of up to 200% or more.
    Type: Application
    Filed: November 10, 2004
    Publication date: May 11, 2006
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventor: Stuart Parkin
  • Publication number: 20060093862
    Abstract: Magnetic material, which is not normally bcc-structured under ambient conditions, is induced into becoming bcc as a result of its proximity to a suitable templating material, such as a bcc-structured underlayer that is in contact with the magnetic material. The magnetic material, in combination with a tunnel barrier and other elements, forms a magnetic tunneling device, such as a magnetic tunnel junction that may have a tunneling magnetoresistance of 100% or more. Suitable tunnel barriers include MgO and Mg—ZnO, and the magnetic material may be Co. The templating material may include such elements as V, Cr, Nb, Mo, and W, or the tunnel barrier MgO may itself serve as the templating material.
    Type: Application
    Filed: October 29, 2004
    Publication date: May 4, 2006
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventor: Stuart Parkin
  • Publication number: 20060028866
    Abstract: A data storage device includes a unpatterned magnetic film having data regions in which to store data. A track is disposed in proximity to the magnetic film, such that the track selectively defines a shiftable magnetic domain wall. In order to select a data bit that is stored in one of the data regions of the magnetic film, a fringing field of the magnetic domain wall in the track is used to selectively change a direction of a magnetic moment in the data region.
    Type: Application
    Filed: October 3, 2005
    Publication date: February 9, 2006
    Inventor: Stuart Parkin
  • Publication number: 20060012926
    Abstract: Magnetic tunneling devices are formed from a first body centered cubic (bcc) magnetic layer and a second bcc magnetic layer. At least one spacer layer of bcc material between these magnetic layers exchange couples the first and second bcc magnetic layers. A tunnel barrier in proximity with the second magnetic layer permits spin-polarized current to pass between the tunnel barrier and the second layer; the tunnel barrier may be either MgO and Mg—ZnO. The first magnetic layer, the spacer layer, the second magnetic layer, and the tunnel barrier are all preferably (100) oriented. The MgO and Mg—ZnO tunnel barriers are prepared by first depositing a metallic layer on the second magnetic layer (e.g., a Mg layer), thereby substantially reducing the oxygen content in this magnetic layer, which improves the performance of the tunnel barriers.
    Type: Application
    Filed: July 15, 2004
    Publication date: January 19, 2006
    Inventor: Stuart Parkin
  • Publication number: 20060003185
    Abstract: A magnetic tunneling element is constructed from a MgO or Mg—ZnO tunnel barrier and an amorphous magnetic layer in proximity with the tunnel barrier. The amorphous magnetic layer includes Co and at least one additional element selected to make the layer amorphous. Magnetic tunnel junctions formed from the amorphous magnetic layer, the tunnel barrier, and an additional ferromagnetic layer have tunneling magnetoresistance values of up to 200% or more.
    Type: Application
    Filed: July 2, 2004
    Publication date: January 5, 2006
    Inventor: Stuart Parkin
  • Publication number: 20050226043
    Abstract: A magnetic tunnel element that can be used, for example, as part of a read head or a magnetic memory cell, includes a first layer formed from an amorphous material, an amorphous tunnel barrier layer, and an interface layer between the first layer and the tunnel barrier layer. The interface layer is formed from a material that is crystalline when the material is in isolation from both the first layer and the tunnel barrier layer. Alternatively, the thickness of the interface layer is selected so that the interface layer is not crystalline. The first layer is formed from at least one material selected from the group consisting of amorphous ferromagnetic material, amorphous ferrimagnetic materials, and amorphous non-magnetic materials. The interface layer is formed from a material selected from the group consisting of a ferromagnetic material and a ferrimagnetic material.
    Type: Application
    Filed: June 13, 2005
    Publication date: October 13, 2005
    Applicant: International Business Machines Corporation
    Inventors: Stuart Parkin, Mahesh Samant