Patents by Inventor Witold Kula

Witold Kula 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: 9373775
    Abstract: Methods of forming memory cells, magnetic memory cell structures, and arrays of magnetic memory cell structures are disclosed. Embodiments of the methods include patterning a precursor structure to form a stepped structure including at least an upper discrete feature section and a lower feature section with a broader width, length, or both than the upper discrete feature section. The method uses patterning acts directed along a first axis, e.g., an x-axis, and then along a second axis, e.g., a y-axis, that is perpendicular to or about perpendicular to the first axis. The patterning acts may therefore allow for more unifoimity between a plurality of formed, neighboring cell core structures, even at dimensions below about thirty nanometers. Magnetic memory structures and memory cell arrays are also disclosed.
    Type: Grant
    Filed: September 13, 2012
    Date of Patent: June 21, 2016
    Assignee: Micron Technology, Inc.
    Inventors: Gurtej S. Sandhu, Witold Kula, Wayne I. Kinney
  • Patent number: 9373778
    Abstract: A MTJ for a spintronic device includes a thin seed layer that enhances perpendicular magnetic anisotropy (PMA) in an overlying laminated layer with a (Co/Ni)n composition or the like where n is from 2 to 30. The seed layer is preferably NiCr, NiFeCr, Hf, or a composite thereof with a thickness from 10 to 100 Angstroms. Furthermore, a magnetic layer such as CoFeB may be formed between the laminated layer and a tunnel barrier layer to serve as a transitional layer between a (111) laminate and (100) MgO tunnel barrier. There may be a Ta insertion layer between the CoFeB layer and laminated layer to promote (100) crystallization in the CoFeB layer. The laminated layer may be used as a dipole layer in a MTJ. Annealing between 300° C. and 400° C. may be used to further enhance PMA in the laminated layer.
    Type: Grant
    Filed: October 31, 2014
    Date of Patent: June 21, 2016
    Assignee: Headway Technologies, Inc.
    Inventors: Guenole Jan, Witold Kula, Ru Ying Tong, Yu Jen Wang
  • Patent number: 9368714
    Abstract: A magnetic cell core includes at least one stressor structure proximate to a magnetic region (e.g., a free region or a fixed region). The magnetic region may be formed of a magnetic material exhibiting magnetostriction. During switching, the stressor structure may be subjected to a programming current passing through the magnetic cell core. In response to the current, the stressor structure may alter in size. Due to the size change, the stressor structure may exert a stress upon the magnetic region and, thereby, alter its magnetic anisotropy. In some embodiments, the MA strength of the magnetic region may be lowered during switching so that a lower programming current may be used to switch the magnetic orientation of the free region. In some embodiments, multiple stressor structures may be included in the magnetic cell core. Methods of fabrication and operation and related device structures and systems are also disclosed.
    Type: Grant
    Filed: July 1, 2013
    Date of Patent: June 14, 2016
    Assignee: Micron Technology, Inc.
    Inventors: Gurtej S. Sandhu, Witold Kula
  • Publication number: 20160163967
    Abstract: A magnetic tunnel junction includes a conductive first magnetic electrode that includes magnetic recording material. A conductive second magnetic electrode is spaced from the first electrode and includes magnetic reference material. A non-magnetic tunnel insulator material is between the first and second electrodes. The magnetic reference material of the second electrode includes a non-magnetic region comprising elemental iridium. The magnetic reference material includes a magnetic region comprising elemental cobalt or a cobalt-rich alloy between the non-magnetic region and the tunnel insulator material.
    Type: Application
    Filed: December 8, 2014
    Publication date: June 9, 2016
    Inventors: Wei Chen, Witold Kula, Jonathan D. Harms, Sunil S. Murthy
  • Patent number: 9356229
    Abstract: Memory cells are disclosed. Magnetic regions within the memory cells include an alternating structure of magnetic sub-regions and coupler sub-regions. The coupler material of the coupler sub-regions antiferromagnetically couples neighboring magnetic sub-regions and effects or encourages a vertical magnetic orientation exhibited by the neighboring magnetic sub-regions. Neighboring magnetic sub-regions, spaced from one another by a coupler sub-region, exhibit oppositely-directed magnetic orientations. The magnetic and coupler sub-regions may each be of a thickness tailored to form the magnetic region in a compact structure. Interference between magnetic dipole fields emitted from the magnetic region on switching of a free region in the memory cell may be reduced or eliminated. Also disclosed are semiconductor device structures, spin torque transfer magnetic random access memory (STT-MRAM) systems, and methods of fabrication.
    Type: Grant
    Filed: June 2, 2015
    Date of Patent: May 31, 2016
    Assignee: Micron Technology, Inc.
    Inventors: Wayne I. Kinney, Witold Kula, Stephen J. Kramer
  • Patent number: 9331269
    Abstract: Spin transfer torque memory cells and methods of forming the same are described herein. As an example, spin transfer torque memory cells may include an amorphous material, a storage material formed on the amorphous material, wherein the storage material is substantially boron free, an interfacial perpendicular magnetic anisotropy material formed on the storage material, a reference material formed on the interfacial perpendicular magnetic anisotropy material, wherein the reference material is substantially boron free, a buffer material formed on the reference material and a pinning material formed on the buffer material.
    Type: Grant
    Filed: July 31, 2014
    Date of Patent: May 3, 2016
    Assignee: Micron Technology, Inc.
    Inventors: Manzar Siddik, Witold Kula
  • Patent number: 9331271
    Abstract: A STT-RAM MTJ is disclosed with a MgO tunnel barrier formed by natural oxidation and containing an oxygen surfactant layer to form a more uniform MgO layer and lower breakdown distribution percent. A CoFeB/NCC/CoFeB composite free layer with a middle nanocurrent channel layer minimizes Jc0 while enabling thermal stability, write voltage, read voltage, and Hc values that satisfy 64 Mb design requirements. The NCC layer has RM grains in an insulator matrix where R is Co, Fe, or Ni, and M is a metal such as Si or Al. NCC thickness is maintained around the minimum RM grain size to avoid RM granules not having sufficient diameter to bridge the distance between upper and lower CoFeB layers. A second NCC layer and third CoFeB layer may be included in the free layer or a second NCC layer may be inserted below the Ru capping layer.
    Type: Grant
    Filed: December 6, 2013
    Date of Patent: May 3, 2016
    Assignee: Headway Technologies, Inc.
    Inventors: Cheng T. Horng, Ru-Ying Tong, Guangli Liu, Robert Beach, Witold Kula, Tai Min
  • Patent number: 9224940
    Abstract: A MTJ in an MRAM array is disclosed with a composite free layer having a lower crystalline layer contacting a tunnel barrier and an upper amorphous NiFeX layer for improved bit switching performance. The crystalline layer is Fe, Ni, or FeB with a thickness of at least 6 Angstroms which affords a high magnetoresistive ratio. The X element in the NiFeX layer is Mg, Hf, Zr, Nb, or Ta with a content of 5 to 30 atomic %. NiFeX thickness is preferably between 20 to 40 Angstroms to substantially reduce bit line switching current and number of shorted bits. In an alternative embodiment, the crystalline layer may be a Fe/NiFe bilayer. Optionally, the amorphous layer may have a NiFeM1/NiFeM2 configuration where M1 and M2 are Mg, Hf, Zr, Nb, or Ta, and M1 is unequal to M2. Annealing at 300° C. to 360° C. provides a high magnetoresistive ratio of about 150%.
    Type: Grant
    Filed: June 26, 2014
    Date of Patent: December 29, 2015
    Assignee: Headway Technologies, Inc.
    Inventors: Wei Cao, Cheng T. Horng, Witold Kula, Chyu Jiuh Torng
  • Publication number: 20150303374
    Abstract: Spin transfer torque memory cells and methods of forming the same are described herein. As an example, spin transfer torque memory cells may include an amorphous material, a storage material formed on the amorphous material, wherein the storage material is substantially boron free, an interfacial perpendicular magnetic anisotropy material formed on the storage material, a reference material formed on the interfacial perpendicular magnetic anisotropy material, wherein the reference material is substantially boron free, a buffer material formed on the reference material and a pinning material formed on the buffer material.
    Type: Application
    Filed: July 31, 2014
    Publication date: October 22, 2015
    Inventors: Manzar Siddik, Witold Kula
  • Patent number: 9159908
    Abstract: A magnetic tunneling junction (MTJ) in an MRAM array is disclosed with a composite free layer having a FL1/FL2/FL3 configuration where FL1 and FL2 are crystalline magnetic layers and FL3 is an amorphous NiFeX layer for improved bit switching performance. FL1 layer is CoFe which affords a high magnetoresistive (MR) ratio when forming an interface with a MgO tunnel barrier. FL2 is Fe to improve switching performance. NiFeX thickness where X is Hf is preferably between 20 to 40 Angstroms to substantially reduce bit line switching current and number of shorted bits. Annealing at 330° C. to 360° C. provides a high MR ratio of 190%. Furthermore, low Hc and Hk are simultaneously achieved with improved bit switching performance and fewer shorts without compromising other MTJ properties such as MR ratio. As a result of high MR ratio and lower bit-to-bit resistance variation, higher reading margin is realized.
    Type: Grant
    Filed: May 5, 2011
    Date of Patent: October 13, 2015
    Assignee: Headway Technologies, Inc.
    Inventors: Wei Cao, Witold Kula
  • Publication number: 20150263269
    Abstract: Memory cells are disclosed. Magnetic regions within the memory cells include an alternating structure of magnetic sub-regions and coupler sub-regions. The coupler material of the coupler sub-regions antiferromagnetically couples neighboring magnetic sub-regions and effects or encourages a vertical magnetic orientation exhibited by the neighboring magnetic sub-regions. Neighboring magnetic sub-regions, spaced from one another by a coupler sub-region, exhibit oppositely-directed magnetic orientations. The magnetic and coupler sub-regions may each be of a thickness tailored to form the magnetic region in a compact structure. Interference between magnetic dipole fields emitted from the magnetic region on switching of a free region in the memory cell may be reduced or eliminated. Also disclosed are semiconductor device structures, spin torque transfer magnetic random access memory (STT-MRAM) systems, and methods of fabrication.
    Type: Application
    Filed: June 2, 2015
    Publication date: September 17, 2015
    Inventors: Wayne I. Kinney, Witold Kula, Stephen J. Kramer
  • Publication number: 20150249202
    Abstract: A magnetic cell includes a magnetic region formed from a precursor magnetic material comprising a diffusible species and at least one other species. An oxide region is disposed between the magnetic region and another magnetic region, and an amorphous region is proximate to the magnetic region. The amorphous region comprises an attracter material that has a chemical affinity for the diffusible species that is higher than a chemical affinity of the at least one other species for the diffusible species. Thus, the diffusible species is transferred from the precursor magnetic material to the attracter material, forming a depleted magnetic material. The removal of the diffusible species and the amorphous nature of the region of the attracter material promotes crystallization of the depleted magnetic material, which enables high tunnel magnetoresistance and high magnetic anisotropy strength. Methods of fabrication and semiconductor devices are also disclosed.
    Type: Application
    Filed: February 28, 2014
    Publication date: September 3, 2015
    Applicant: Micron Technology, Inc.
    Inventors: Manzar Siddik, Witold Kula
  • Patent number: 9054030
    Abstract: Memory cells are disclosed. Magnetic regions within the memory cells include an alternating structure of magnetic sub-regions and coupler sub-regions. The coupler material of the coupler sub-regions antiferromagnetically couples neighboring magnetic sub-regions and effects or encourages a vertical magnetic orientation exhibited by the neighboring magnetic sub-regions. Neighboring magnetic sub-regions, spaced from one another by a coupler sub-region, exhibit oppositely-directed magnetic orientations. The magnetic and coupler sub-regions may each be of a thickness tailored to form the magnetic region in a compact structure. Interference between magnetic dipole fields emitted from the magnetic region on switching of a free region in the memory cell may be reduced or eliminated. Also disclosed are semiconductor device structures, spin torque transfer magnetic random access memory (STT-MRAM) systems, and methods of fabrication.
    Type: Grant
    Filed: June 19, 2012
    Date of Patent: June 9, 2015
    Assignee: Micron Technology, Inc.
    Inventors: Wayne I. Kinney, Witold Kula, Stephen J. Kramer
  • Patent number: 9048411
    Abstract: A magnetic element is disclosed that has a composite free layer with a FM1/moment diluting/FM2 configuration wherein FM1 and FM2 are magnetic layers made of one or more of Co, Fe, Ni, and B and the moment diluting layer is used to reduce the perpendicular demagnetizing field. As a result, lower resistance x area product and higher thermal stability are realized when perpendicular surface anisotropy dominates shape anisotropy to give a magnetization perpendicular to the planes of the FM1, FM2 layers. The moment diluting layer may be a non-magnetic metal like Ta or a CoFe alloy with a doped non-magnetic metal. A perpendicular Hk enhancing layer interfaces with the FM2 layer and may be an oxide to increase the perpendicular anisotropy field in the FM2 layer. A method for forming the magnetic element is also provided.
    Type: Grant
    Filed: October 7, 2013
    Date of Patent: June 2, 2015
    Assignee: Headway Technologies, Inc.
    Inventors: Guenole Jan, Ru Ying Tong, Witold Kula
  • Publication number: 20150137291
    Abstract: Methods of forming magnetic memory cells are disclosed. Magnetic and non-magnetic materials are formed into a primal precursor structure in an initial stress state of essentially no strain, compressive strain, or tensile strain. A stress-compensating material, e.g., a non-sacrificial, conductive material, is formed to be disposed on the primal precursor structure to form a stress-compensated precursor structure in a net beneficial stress state. Thereafter, the stress-compensated precursor structure may be patterned to form a cell core of a memory cell. The net beneficial stress state of the stress-compensated precursor structure lends to formation of one or more magnetic regions, in the cell core, exhibiting a vertical magnetic orientation without deteriorating a magnetic strength of the one or more magnetic regions. Also disclosed are memory cells, memory cell structures, semiconductor device structures, and spin torque transfer magnetic random access memory (STT-MRAM) systems.
    Type: Application
    Filed: December 24, 2014
    Publication date: May 21, 2015
    Inventors: Witold Kula, Gurtej S. Sandhu, Stephen J. Kramer
  • Patent number: 9006704
    Abstract: A magnetic element is disclosed wherein first and second interfaces of a free layer with a Hk enhancing layer and tunnel barrier, respectively, produce enhanced surface perpendicular anisotropy to lower switching current or increase thermal stability in a magnetic tunnel junction (MTJ). In a MTJ with a bottom spin valve configuration where the Hk enhancing layer is an oxide, the capping layer contacting the Hk enhancing layer is selected to have a free energy of oxide formation substantially greater than that of the oxide. The free layer may be a single layer or composite comprised of an Fe rich alloy such as Co20Fe60B20. With a thin free layer, the interfacial perpendicular anisotropy may dominate the shape anisotropy to generate a magnetization perpendicular to the planes of the layers. The magnetic element may be part of a spintronic device or serve as a propagation medium in a domain wall motion device.
    Type: Grant
    Filed: February 11, 2011
    Date of Patent: April 14, 2015
    Assignee: Headway Technologies, Inc.
    Inventors: Guenole Jan, Ru Ying Tong, Witold Kula, Cheng Horng
  • Publication number: 20150076485
    Abstract: A magnetic cell includes a free region between an intermediate oxide region (e.g., a tunnel barrier) and a secondary oxide region. Both oxide regions may be configured to induce magnetic anisotropy (“MA”) with the free region, enhancing the MA strength of the free region. A getter material proximate to the secondary oxide region is formulated and configured to remove oxygen from the secondary oxide region to reduce an oxygen concentration and, thus, an electrical resistance of the secondary oxide region. Thus, the secondary oxide region contributes only minimally to the electrical resistance of the cell core. Embodiments of the present disclosure therefore enable a high effective magnetoresistance, low resistance area product, and low programming voltage along with the enhanced MA strength. Methods of fabrication, memory arrays, memory systems, and electronic systems are also disclosed.
    Type: Application
    Filed: September 13, 2013
    Publication date: March 19, 2015
    Applicant: Micron Technology, Inc.
    Inventors: Gurtej S. Sandhu, Witold Kula
  • Publication number: 20150076633
    Abstract: A magnetic cell includes an attracter material proximate to a magnetic region (e.g., a free region). The attracter material is formulated to have a higher chemical affinity for a diffusible species of a magnetic material, from which the magnetic region is formed, compared to a chemical affinity between the diffusible species and at least another species of the magnetic material. Thus, the diffusible species is removed from the magnetic material to the attracter material. The removal accommodates crystallization of the depleted magnetic material. The crystallized, depleted magnetic material enables a high tunnel magneto resistance, high energy barrier, and high energy barrier ratio. The magnetic region may be formed as a continuous magnetic material, thus enabling a high exchange stiffness, and positioning the magnetic region between two magnetic anisotropy-inducing oxide regions enables a high magnetic anisotropy strength. Methods of fabrication and semiconductor devices are also disclosed.
    Type: Application
    Filed: September 18, 2013
    Publication date: March 19, 2015
    Applicant: Micron Technology
    Inventors: Manzar Siddik, Andy Lyle, Witold Kula
  • Patent number: 8981503
    Abstract: An STT MTJ cell is formed with a magnetic anisotropy of its free and reference layers that is perpendicular to their planes of formation. The reference layer of the cell is an SAF multilayered structure with a single magnetic domain to enhance the bi-stability of the magnetoresistive states of the cell. The free layer of the cell is etched back laterally from the reference layer, so that the fringing stray field of the reference layer is no more than 15% of the coercivity of the free layer and has minimal effect on the free layer.
    Type: Grant
    Filed: March 16, 2012
    Date of Patent: March 17, 2015
    Assignee: Headway Technologies, Inc.
    Inventors: Robert Beach, Guenole Jan, Yu-Jen Wang, Witold Kula, Po-Kang Wang
  • Publication number: 20150061055
    Abstract: A MTJ for a spintronic device is disclosed and includes a thin seed layer that enhances perpendicular magnetic anisotropy (PMA) in an overlying laminated layer with a (Co/Ni)n composition or the like where n is from 2 to 30. The seed layer is preferably NiCr, NiFeCr, Hf, or a composite thereof with a thickness from 10 to 100 Angstroms. Furthermore, a magnetic layer such as CoFeB may be formed between the laminated layer and a tunnel barrier layer to serve as a transitional layer between a (111) laminate and (100) MgO tunnel barrier. There may be a Ta insertion layer between the CoFeB layer and laminated layer to promote (100) crystallization in the CoFeB layer. The laminated layer may be used as a reference layer in a MTJ. Annealing between 300° C. and 400° C. may be used to further enhance PMA in the laminated layer.
    Type: Application
    Filed: October 31, 2014
    Publication date: March 5, 2015
    Inventors: Guenole Jan, Witold Kula, Ru Ying Tong, Yu Jen Wang