Patents by Inventor Daniel C. Worledge

Daniel C. Worledge 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: 8836058
    Abstract: A magnetic device includes a first electrode portion, a free layer portion arranged on the first electrode portion, the free layer portion including a magnetic insulating material, a reference layer portion contacting the free layer portion, the reference layer portion including a magnetic metallic layer, and a second electrode portion arranged on the reference layer portion.
    Type: Grant
    Filed: November 29, 2012
    Date of Patent: September 16, 2014
    Assignee: International Business Machines Corporation
    Inventors: Marcin J. Gajek, Daniel C. Worledge
  • Publication number: 20140217524
    Abstract: A magnetic logic cell includes a first electrode portion, a magnetic portion arranged on the first electrode, the magnetic portion including an anti-ferromagnetic material or a ferrimagnetic material, a dielectric portion arranged on the magnetic portion, and a second electrode portion arranged on the dielectric portion.
    Type: Application
    Filed: February 7, 2013
    Publication date: August 7, 2014
    Applicants: THE BOARD OF TRUSTEES OF THE UNIVERSITY OF ALABAMA, INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Marcin J. Gajek, Daniel C. Worledge, William H. Butler
  • Patent number: 8796045
    Abstract: A method of forming a magnetic random access memory (MRAM) device includes forming at least one write line, forming a first insulating layer over the at least one write line and forming a heating line on the first insulating layer. The method includes forming at least one tunnel junction above the at least one write line, the at least one tunnel junction connected to the heating line, forming a second insulating layer on the heating line and forming heat current supply vias at each end of the current line. The method further includes forming heat current supply lines connected to each heat current supply via and forming at least one read line above the at least one tunnel junction and physically connected to the at least one tunnel junction.
    Type: Grant
    Filed: November 29, 2012
    Date of Patent: August 5, 2014
    Assignee: International Business Machines Corporation
    Inventor: Daniel C. Worledge
  • Publication number: 20140169082
    Abstract: A thermal spin torque transfer magnetoresistive random access memory (MRAM) apparatus includes a magnetic tunnel junction and a tunnel junction programming circuit. The magnetic tunnel junction includes a reference layer having a fixed magnetic polarity, a tunnel barrier layer, and a free layer on an opposite side of the tunnel barrier layer from the reference layer. The free layer includes a first layer having a first Curie temperature and a second layer having a second Curie temperature different from the first Curie temperature. The tunnel junction programming circuit is configured to apply a current through the magnetic tunnel junction to generate a write temperature in the magnetic tunnel junction and to write to the free layer of the magnetic tunnel junction.
    Type: Application
    Filed: August 16, 2013
    Publication date: June 19, 2014
    Applicant: International Business Machines Corporation
    Inventors: Daniel C. Worledge, Guohan Hu
  • Publication number: 20140169080
    Abstract: A thermal spin torque transfer magnetoresistive random access memory (MRAM) apparatus includes a magnetic tunnel junction and a tunnel junction programming circuit. The magnetic tunnel junction includes a reference layer having a fixed magnetic polarity, a tunnel barrier layer, and a free layer on an opposite side of the tunnel barrier layer from the reference layer. The free layer includes a first layer having a first Curie temperature and a second layer having a second Curie temperature different from the first Curie temperature. The tunnel junction programming circuit is configured to apply a current through the magnetic tunnel junction to generate a write temperature in the magnetic tunnel junction and to write to the free layer of the magnetic tunnel junction.
    Type: Application
    Filed: December 17, 2012
    Publication date: June 19, 2014
    Applicant: International Business Machines Corporation
    Inventors: Daniel C. Worledge, Guohan Hu
  • Publication number: 20140151620
    Abstract: A method for fabricating a spintronic cell includes forming a cavity in a substrate, forming a wire in the cavity, depositing a spacer layer over exposed portions of the substrate and the conductive field line, depositing a layer of conductive material on a portion of the spacer layer, removing portions of the layer of conductive material to define a conductive strap portion, wherein the conductive strap portion has a first distal region a second distal region and a medial region arranged therebetween, wherein the medial region has a cross sectional area that is less than a cross sectional area of the first distal region and a cross sectional area of the second distal region, and forming an spintronic device stack on the conductive strap portion above the conductive field line.
    Type: Application
    Filed: August 6, 2013
    Publication date: June 5, 2014
    Applicant: International Business Machines Corporation
    Inventors: David W. Abraham, Philip L. Trouilloud, Daniel C. Worledge
  • Publication number: 20140145278
    Abstract: A magnetic device includes a first electrode portion, a free layer portion arranged on the first electrode portion, the free layer portion including a magnetic insulating material, a reference layer portion contacting the free layer portion, the reference layer portion including a magnetic metallic layer, and a second electrode portion arranged on the reference layer portion.
    Type: Application
    Filed: November 29, 2012
    Publication date: May 29, 2014
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Marcin J. Gajek, Daniel C. Worledge
  • Publication number: 20140124880
    Abstract: A magnetic random access memory (MRAM) device includes at least one read line, at least one write line and a tunnel junction extending from the at least one read line toward the at least one write line. A heating line is connected to an opposite end of the tunnel junction from the at least one read line. The heating line is configured to supply heat to the tunnel junction to heat the tunnel junction based on current flowing through the heating line.
    Type: Application
    Filed: November 6, 2012
    Publication date: May 8, 2014
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventor: Daniel C. Worledge
  • Publication number: 20140127831
    Abstract: A method of forming a magnetic random access memory (MRAM) device includes forming at least one write line, forming a first insulating layer over the at least one write line and forming a heating line on the first insulating layer. The method includes forming at least one tunnel junction above the at least one write line, the at least one tunnel junction connected to the heating line, forming a second insulating layer on the heating line and forming heat current supply vias at each end of the current line. The method further includes forming heat current supply lines connected to each heat current supply via and forming at least one read line above the at least one tunnel junction and physically connected to the at least one tunnel junction.
    Type: Application
    Filed: November 29, 2012
    Publication date: May 8, 2014
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventor: Daniel C. Worledge
  • Publication number: 20140037990
    Abstract: A synthetic antiferromagnetic device includes a reference layer having a first and second ruthenium layer, a magnesium oxide spacer layer disposed on the reference layer, a cobalt iron boron layer disposed on the magnesium oxide spacer layer and a third ruthenium layer disposed on the cobalt iron boron layer, the third ruthenium layer having a thickness of approximately 0 angstroms to 18 angstroms.
    Type: Application
    Filed: July 31, 2012
    Publication date: February 6, 2014
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: David W. Abraham, Michael C. Gaidis, Janusz J. Nowak, Daniel C. Worledge
  • Publication number: 20140038309
    Abstract: A method for fabricating a synthetic antiferromagnetic device, includes depositing a magnesium oxide spacer layer on a reference layer having a first and second ruthenium layer, depositing a cobalt iron boron layer on the magnesium oxide spacer layer; and depositing a third ruthenium layer on the cobalt iron boron layer, the third ruthenium layer having a thickness of approximately 0-18 angstroms.
    Type: Application
    Filed: August 3, 2012
    Publication date: February 6, 2014
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: David W. Abraham, Michael C. Gaidis, Janusz J. Nowak, Daniel C. Worledge
  • Patent number: 8536668
    Abstract: A magnetic layer that includes a seed layer comprising at least tantalum and a free magnetic layer comprising at least iron. The free magnetic layer is grown on top of the seed layer and the free magnetic layer is perpendicularly magnetized. The magnetic layer may be included in a magnetic tunnel junction (MTJ) stack.
    Type: Grant
    Filed: August 9, 2012
    Date of Patent: September 17, 2013
    Assignee: International Business Machines Corporation
    Inventor: Daniel C. Worledge
  • Patent number: 8482968
    Abstract: An example embodiment is an apparatus for controlling a magnetic direction of a magnetic free layer. The apparatus includes a writer with a first magnetic write layer and a second magnetic write layer. Applying a write voltage across first and second magnetic write layers causes a magnetic anisotropy of one of the magnetic write layers to switch from parallel to the plane of the magnetic write layers to orthogonal to the plane of the magnetic write layers. The magnetic write layer with the magnetic anisotropy parallel to the plane of the magnetic write layers induces the magnetic direction in the magnetic free layer.
    Type: Grant
    Filed: November 13, 2010
    Date of Patent: July 9, 2013
    Assignee: International Business Machines Corporation
    Inventor: Daniel C. Worledge
  • Patent number: 8456895
    Abstract: A mechanism is provided for bidirectional writing. A structure includes a reference layer on top of a tunnel barrier, a free layer underneath the tunnel barrier, a metal spacer underneath the free layer, an insulating magnet underneath the metal spacer, and a high resistance layer underneath the insulating layer. The high resistance layer acts as a heater in which the heater heats the insulating magnet to generate spin polarized electrons. A magnetization of the free layer is destabilized by the spin polarized electrons generated from the insulating magnet. A voltage is applied to change the magnetization of the free layer when the magnetization is destabilized. A polarity of the voltage determines when the magnetization of the free layer is parallel and antiparallel to a magnetization of the reference layer.
    Type: Grant
    Filed: May 3, 2011
    Date of Patent: June 4, 2013
    Assignee: International Business Machines Corporation
    Inventors: David W. Abraham, Niladri N. Mojumder, Daniel C. Worledge
  • Publication number: 20130119495
    Abstract: Semiconductor stack structures such as magnetic tunnel junction structures having a magnetic free layer that is grown on composite, obliquely deposited seed layers to induce an increased in-plane magnetic anisotropy Hk of the magnetic free layer. In one aspect, a semiconductor device includes a composite seed layer formed on a substrate, and a magnetic layer formed on the composite seed layer. The composite seed layer includes a first seed layer obliquely formed with an incident angle from a surface normal of the substrate along a first direction of the substrate, and a second seed layer obliquely formed with the incident angle on the first seed layer along a second direction of the substrate, opposite the first direction.
    Type: Application
    Filed: November 11, 2011
    Publication date: May 16, 2013
    Applicant: International Business Machines Corporation
    Inventors: Francesco A. VetrĂ², Daniel C. Worledge
  • Patent number: 8406040
    Abstract: A magnetic tunnel junction stack including a pinned magnetic layer, a tunnel barrier layer formed of magnesium oxide (MgO), a free magnetic layer adjacent to the tunnel barrier layer, and a layer of vanadium (V) adjacent to the free magnetic layer.
    Type: Grant
    Filed: January 8, 2010
    Date of Patent: March 26, 2013
    Assignee: International Business Machines Corporation
    Inventors: Daniel C. Worledge, Guohan Hu, Jonathan Z. Sun
  • Patent number: 8370714
    Abstract: A method of reading and correcting data within a memory device that includes reading each data bit of a data word using a plurality of reference cells corresponding to each data bit, performing error detection on the read data bits, and correcting a read data bit when an error is detected using error correction code (ECC) and writing each corresponding reference cells to an original memory state thereof.
    Type: Grant
    Filed: January 8, 2010
    Date of Patent: February 5, 2013
    Assignee: International Business Machines Corporation
    Inventors: John K. DeBrosse, Daniel C. Worledge
  • Publication number: 20130005052
    Abstract: A magnetic tunnel junction (MTJ) for a magnetic random access memory (MRAM) includes a magnetic free layer having a variable magnetization direction; an iron (Fe) dusting layer formed on the free layer; an insulating tunnel barrier formed on the dusting layer; and a magnetic fixed layer having an invariable magnetization direction, disposed adjacent the tunnel barrier such that the tunnel barrier is located between the free layer and the fixed layer; wherein the free layer and the fixed layer have perpendicular magnetic anisotropy and are magnetically coupled through the tunnel barrier.
    Type: Application
    Filed: September 5, 2012
    Publication date: January 3, 2013
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Guohan Hu, Janusz J. Nowak, Philip L. Trouilloud, Daniel C. Worledge
  • Publication number: 20130005051
    Abstract: A magnetic tunnel junction (MTJ) includes a magnetic free layer, having a variable magnetization direction; an insulating tunnel barrier located adjacent to the free layer; a magnetic fixed layer having an invariable magnetization direction, the fixed layer disposed adjacent the tunnel barrier such that the tunnel barrier is located between the free layer and the fixed layer, wherein the free layer and the fixed layer have perpendicular magnetic anisotropy; and one or more of: a composite fixed layer, the composite fixed layer comprising a dusting layer, a spacer layer, and a reference layer; a synthetic antiferromagnetic (SAF) fixed layer structure, the SAF fixed layer structure comprising a SAF spacer located between the fixed layer and a second fixed magnetic layer; and a dipole layer, wherein the free layer is located between the dipole layer and the tunnel barrier.
    Type: Application
    Filed: September 4, 2012
    Publication date: January 3, 2013
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Guohan Hu, Janusz J. Nowak, Philip L. Trouilloud, Daniel C. Worledge
  • Publication number: 20120326250
    Abstract: Embodiments are directed to STT MRAM devices. One embodiment of an STT MRAM device includes a reference layer, a tunnel barrier layer, a free layer and one or more conductive vias. The reference layer is configured to have a fixed magnetic moment. In addition, the tunnel barrier layer is configured to enable electrons to tunnel between the reference layer and the free layer through the tunnel barrier layer. The free layer is disposed beneath the tunnel barrier layer and is configured to have an adaptable magnetic moment for the storage of data. The conductive via is disposed beneath the free layer and is connected to an electrode. Further, the conductive via has a width that is smaller than a width of the free layer such that a width of an active STT area for the storage of data in the free layer is defined by the width of the conductive via.
    Type: Application
    Filed: June 24, 2011
    Publication date: December 27, 2012
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: MICHAEL C. GAIDIS, JANUSZ J. NOWAK, DANIEL C. WORLEDGE