Having Tunnel Junction Effect Patents (Class 428/811.1)
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Patent number: 11705152Abstract: A magnetic head includes a first magnetic pole, a second magnetic pole, and a stacked body provided between the first and second magnetic poles. The stacked body includes a first magnetic member, a second magnetic member provided between the first magnetic member and the second magnetic pole, a first layer provided between the first and second magnetic members, and a second layer provided between the second magnetic member and the second magnetic pole. The first magnetic member includes first magnetic regions and a first nonmagnetic region. The first nonmagnetic region is between the one of the first magnetic regions and the other one of the first magnetic regions.Type: GrantFiled: August 5, 2022Date of Patent: July 18, 2023Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATIONInventors: Hitoshi Iwasaki, Naoyuki Narita, Hirofumi Suto, Masayuki Takagishi, Tazumi Nagasawa
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Patent number: 11239278Abstract: A dielectric spacer is formed laterally adjacent to a bottom conductive structure. The dielectric spacer is configured to limit the area in which a subsequently formed top contact structure can contact the bottom conductive structure. In some embodiments, only a topmost surface of the bottom conductive structure is contacted by the top contact structure. In other embodiments, a topmost surface and an upper sidewall surface of the bottom conductive structure is contacted by the top contact structure.Type: GrantFiled: February 4, 2020Date of Patent: February 1, 2022Assignee: International Business Machines CorporationInventors: Chih-Chao Yang, Baozhen Li, Theodorus E. Standaert, Koichi Motoyama
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Patent number: 10811068Abstract: Varying energy barriers of magnetic tunnel junctions (MTJs) in different magneto-resistive random access memory (MRAM) arrays in a semiconductor die to facilitate use of MRAM for different memory applications is disclosed. In one aspect, energy barriers of MTJs in different MRAM arrays are varied. The energy barrier of an MTJ affects its write performance as the amount of switching current required to switch the magnetic orientation of a free layer of the MTJ is a function of its energy barrier. Thus, by varying the energy barriers of the MTJs in different MRAM arrays in a semiconductor die, different MRAM arrays may be used for different types of memory provided in the semiconductor die while still achieving distinct performance specifications. The energy barrier of an MTJ can be varied by varying the materials, heights, widths, and/or other characteristics of MTJ stacks.Type: GrantFiled: January 14, 2019Date of Patent: October 20, 2020Assignee: Qualcomm IncorporatedInventors: Xia Li, Wei-Chuan Chen, Wah Nam Hsu, Seung Hyuk Kang
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Patent number: 10553642Abstract: A magnetic junction, a memory using the magnetic junction and method for providing the magnetic junction are described. The magnetic junction resides on a substrate and is usable in a magnetic device. The magnetic junction includes a reference layer, a nonmagnetic spacer layer and a M-containing oxide layer adjacent to the free layer. M includes at least one of Ti, Al, Hf, Zr, Mo, V and Nb. The free layer is switchable between a plurality of stable magnetic states when a write current is passed through the magnetic junction. The nonmagnetic spacer layer is between the reference layer and the free layer. The free layer is between the nonmagnetic spacer layer and the M-containing oxide layer.Type: GrantFiled: October 18, 2017Date of Patent: February 4, 2020Assignee: Samsung Electronics Co., Ltd.Inventors: Don Koun Lee, Mohamad Towfik Krounbi, Xueti Tang, Gen Feng, Ikhtiar
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Patent number: 10395707Abstract: A material layer stack for a magnetic tunneling junction, the material layer stack including a fixed magnetic layer; a dielectric layer; a free magnetic layer; and an amorphous electrically-conductive seed layer, wherein the fixed magnetic layer is disposed between the dielectric layer and the seed layer. A non-volatile memory device including a material stack including an amorphous electrically-conductive seed layer; and a fixed magnetic layer juxtaposed and in contact with the seed layer. A method including forming an amorphous seed layer on a first electrode of a memory device; forming a material layer stack on the amorphous seed layer, the material stack including a dielectric layer disposed between a fixed magnetic layer and a free magnetic layer, wherein the fixed magnetic layer.Type: GrantFiled: September 26, 2014Date of Patent: August 27, 2019Assignee: Intel CorporationInventors: Mark L. Doczy, Kaan Oguz, Brian S. Doyle, Charles C. Kuo, Robert S. Chau, Satyarth Suri
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Patent number: 10367137Abstract: Disclosed are an electronic device comprising a semiconductor memory. The semiconductor memory includes a variable resistance element including a free layer having a variable magnetization direction; a pinned layer having a fixed magnetization direction; and a tunnel barrier layer interposed between the free layer and the pinned layer, wherein the free layer includes: a first free layer adjacent to the tunnel barrier layer and having a perpendicular magnetic anisotropy at an interface with the tunnel barrier layer; and a second free layer spaced apart from the tunnel barrier layer by the first free layer and having a saturation magnetization lower than a saturation magnetization of the first free layer.Type: GrantFiled: March 24, 2017Date of Patent: July 30, 2019Assignee: SK hynix Inc.Inventors: Guk-Cheon Kim, Ki-Seon Park, Bo-Mi Lee, Won-Joon Choi, Yang-Kon Kim
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Patent number: 10366653Abstract: An organic light-emitting device including a magnetoresistive element including a first magnetic layer, a second magnetic layer, and a separation layer disposed between the first magnetic layer and the second magnetic layer, an organic light-emitting element electrically connected to the magnetoresistive element, wherein the organic light-emitting element comprises a first electrode, a second electrode, and an organic light-emission layer disposed between the first electrode and the second electrode, a magnetic field applying unit configured to apply a magnetic field to at least the magnetoresistive element, and optionally, to the organic light-emitting element, a power source configured to supply a current between the magnetoresistive element and the organic light-emitting element, and a current source configured to apply a current between both terminals of the organic light-emitting element, wherein light-emission characteristics of the organic light-emitting device are changed depending on a direction andType: GrantFiled: March 6, 2017Date of Patent: July 30, 2019Assignees: SAMSUNG ELECTRONICS CO., LTD., UNIVERSITY OF UTAH RESEARCH FOUNDATIONInventors: Ohyun Kwon, Youngjae Park, Hyun Koo, Byoungki Choi, Zeev Valentine Vardeny, Chuang Zhang, Dali Sun, Zhiyong Pang
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Patent number: 10042559Abstract: This technology provides an electronic device. An electronic device in accordance with an implementation of this document may include a semiconductor memory for storing data, and the semiconductor memory may include a free layer having a variable magnetization direction; a pinned layer having a pinned magnetization direction; a tunnel barrier layer interposed between the free layer and the pinned layer; and an interface enhancement layer interposed between the tunnel barrier layer and the pinned layer, wherein the interface enhancement layer may include an Fe-rich first layer; a Co-rich second layer formed over the first layer; and a metal layer formed over the second layer.Type: GrantFiled: January 30, 2017Date of Patent: August 7, 2018Assignee: SK hynix Inc.Inventors: Yang-Kon Kim, Guk-Cheon Kim, Ku-Youl Jung, Jong-Koo Lim, Won-Joon Choi
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Patent number: 9799842Abstract: Spin-polarized organic light-emitting diodes are provided. Such spin-polarized organic light-emitting diodes incorporate ferromagnetic electrodes and show considerable spin-valve magneto-electroluminescence and magneto-conductivity responses, with voltage and temperature dependencies that originate from the bipolar spin-polarized space charge limited current.Type: GrantFiled: July 3, 2013Date of Patent: October 24, 2017Assignee: University of Utah Research FoundationInventors: Zeev Valentine Vardeny, Tho Duc Nguyen, Eitan Avraham Ehrenfreund
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Patent number: 9472750Abstract: A magnetic junction and method for providing the magnetic junction are described. The magnetic junction includes free and pinned layers separated by a nonmagnetic spacer layer. The free layer is switchable between stable magnetic states when a write current is passed through the magnetic junction. The pinned layer has a perpendicular magnetic anisotropy (PMA) energy greater than its out-of-plane demagnetization energy. Providing the pinned layer includes providing a bulk PMA (B-PMA) layer, providing an interfacial PMA (I-PMA) layer on the B-PMA layer and then providing a sacrificial layer that is a sink for a constituent of the first I-PMA layer. An anneal is then performed. The sacrificial layer and part of the first I-PMA layer are removed after the anneal. Additional I-PMA layer(s) are provided after the removing. A remaining part of the first I-PMA layer and the additional I-PMA layer(s) have a thickness of not more than twenty Angstroms.Type: GrantFiled: December 21, 2015Date of Patent: October 18, 2016Assignee: SAMSUNG ELECTRONICS CO., LTD.Inventors: Xueti Tang, Dustin William Erickson, Jang-Eun Lee
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Patent number: 9178133Abstract: According to one embodiment, a magnetoresistive element includes a recording layer having magnetic anisotropy perpendicular to a film surface and having a variable magnetization direction, a reference layer having magnetic anisotropy perpendicular to a film surface and having an invariable magnetization direction, an intermediate layer provided between the recording layer and the reference layer, and a underlayer containing AlTiN and provided on an opposite side of a surface of the recording layer on which the intermediate layer is provided.Type: GrantFiled: January 21, 2014Date of Patent: November 3, 2015Assignee: Kabushiki Kaisha ToshibaInventors: Eiji Kitagawa, Tadashi Kai, Hiroaki Yoda
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Patent number: 9165627Abstract: Spin Torque Transfer (STT) memory cell structures and methods are described herein. One or more STT memory cell structures comprise an annular STT stack including a nonmagnetic material between a first ferromagnetic material and a second ferromagnetic material and a soft magnetic material surrounding at least a portion of the annular STT stack.Type: GrantFiled: June 25, 2013Date of Patent: October 20, 2015Assignee: Micron Technology, Inc.Inventors: Jun Liu, Gurtej S. Sandhu
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Patent number: 9040178Abstract: A TMR sensor that includes a free layer having at least one B-containing (BC) layer made of CoFeB, CoFeBM, CoB, COBM, or CoBLM, and a plurality of non-B containing (NBC) layers made of CoFe, CoFeM, or CoFeLM is disclosed where L and M are one of Ni, Ta, Ti, W, Zr, Hf, Tb, or Nb. One embodiment is represented by (NBC/BC)n where n?2. A second embodiment is represented by (NBC/BC)n/NBC where n?1. In every embodiment, a NBC layer contacts the tunnel barrier and NBC layers each with a thickness from 2 to 8 Angstroms are formed in alternating fashion with one or more BC layers each 10 to 80 Angstroms thick. Total free layer thickness is <100 Angstroms. The free layer configuration described herein enables a significant noise reduction (SNR enhancement) while realizing a high TMR ratio, low magnetostriction, low RA, and low Hc values.Type: GrantFiled: September 22, 2008Date of Patent: May 26, 2015Assignee: Headway Technologies, Inc.Inventors: Tong Zhao, Hui-Chuan Wang, Yu-Chen Zhou, Min Li, Kunliang Zhang
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Patent number: 9036308Abstract: Various embodiments may be generally directed to a magnetic sensor constructed with a decoupling layer that has a predetermined first morphology. A magnetic free layer can be deposited contactingly adjacent to the decoupling layer with the magnetic free layer configured to have at least a first sub-layer having a predetermined second morphology.Type: GrantFiled: September 21, 2011Date of Patent: May 19, 2015Assignee: Seagate Technology LLCInventors: Mark William Covington, Mark Thomas Kief, Wonjoon Jung
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Patent number: 9034491Abstract: A magnetic element may generally be configured at least with a magnetic stack having a multilayer barrier structure disposed between first and second ferromagnetic layers. The multilayer barrier structure can have a binary compound layer disposed between first and second alloy layers with the binary compound having a metal element and a second element where at least one alloy layer has the metal element and a third element dissimilar from the second element.Type: GrantFiled: November 30, 2012Date of Patent: May 19, 2015Assignee: Seagate Technology LLCInventors: Vijay Karthik Sankar, Mark William Covington
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Publication number: 20150109702Abstract: A tunnel magnetoresistance (TMR) read sensor having a tabbed AFM layer and an extended pinned layer and methods for making the same are provided. The TMR read sensor has an AFM layer recessed from the air bearing surface, providing a reduced shield-to-shield distance.Type: ApplicationFiled: March 31, 2014Publication date: April 23, 2015Applicant: Western Digital (Fremont), LLCInventors: SHAOPING LI, YUANKAI ZHENG, GERARDO A. BERTERO, QUNWEN LENG, MICHAEL L. MALLARY, RONGFU XIAO, MING MAO, ZHIHONG ZHANG, ANUP G. ROY, CHEN JUNG CHIEN, ZHITAO DIAO, LING WANG
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High thermal stability free layer with high out-of-plane anisotropy for magnetic device applications
Patent number: 8946834Abstract: A CoFeB or CoFeNiB magnetic layer wherein the boron content is 25 to 40 atomic % and with a thickness <20 Angstroms is used to achieve high perpendicular magnetic anisotropy and enhanced thermal stability in magnetic devices. A dusting layer made of Co, Ni, Fe or alloy thereof is added to top and bottom surfaces of the CoFeB layer to increase magnetoresistance as well as improve Hc and Hk. Another embodiment includes a non-magnetic metal insertion in the CoFeB free layer. The CoFeB layer with elevated B content may be incorporated as a free layer, dipole layer, or reference layer in STT-MRAM memory elements or in spintronic devices including a spin transfer oscillator. Thermal stability is increased such that substantial Hk is retained after annealing to at least 400° C. for 1 hour. Ku enhancement is achieved and the retention time of a memory cell for STT-MRAM designs is increased.Type: GrantFiled: March 1, 2012Date of Patent: February 3, 2015Assignee: Headway Technologies, Inc.Inventors: Yu-Jen Wang, Witold Kula, Guenole Jan -
Patent number: 8947835Abstract: The invention provides a tunneling magnetoresistance (TMR) read sensor with a long diffusion path and ex-situ interfaces in a sense layer structure. The sense layer structure comprises a first sense layer preferably formed of a ferromagnetic Co—Fe film, a second sense layer preferably formed of a ferromagnetic Co—Fe—B film, and a third sense layer preferably formed of a ferromagnetic Ni—Fe film. The sense layer structure has a long diffusion path (defined as a total thickness of the first and second sense layers) and ex-situ interfaces for suppressing unwanted diffusions of Ni atoms. Alternatively, the sense layer structure comprises a first sense layer preferably formed of a ferromagnetic Co—Fe film, a second sense layer preferably formed of a ferromagnetic Co—Fe—B film, a third sense layer preferably formed of a ferromagnetic Co—Fe—B—Hf film, and a fourth sense layer preferably formed of a ferromagnetic Ni—Fe film.Type: GrantFiled: December 22, 2011Date of Patent: February 3, 2015Assignee: HGST Netherlands B.V.Inventor: Tsann Lin
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Patent number: 8945730Abstract: A storage element including: a storage layer; a magnetization fixed layer; and an insulating layer, wherein by injecting spin-polarized electrons in a laminating direction of a layered structure that includes the storage layer, the insulating layer, and the magnetization fixed layer, the orientation of magnetization of the storage layer changes and recording of information is performed on the storage layer, and an Fe film and a film that includes Ni are formed in order from an interface side that is in contact with the insulating layer, and a graded composition distribution of Ni and Fe is formed after heating on at least one of the storage layer and the magnetization fixed layer.Type: GrantFiled: December 5, 2011Date of Patent: February 3, 2015Assignee: Sony CorporationInventors: Hiroyuki Ohmori, Masanori Hosomi, Kazuhiro Bessho, Yutaka Higo, Kazutaka Yamane, Hiroyuki Uchida, Tetsuya Asayama
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Patent number: 8920947Abstract: Perpendicular magnetic anisotropy and Hc are enhanced in magnetic devices with a Ta/M1/M2 seed layer where M1 is preferably Ti, and M2 is preferably Cu, and including an overlying (Co/Ni)X multilayer (x is 5 to 50) that is deposited with ultra high Ar pressure of >100 sccm to minimize impinging energy that could damage (Co/Ni)X interfaces. In one embodiment, the seed layer is subjected to one or both of a low power plasma treatment and natural oxidation process to form a more uniform interface with the (Co/Ni)X multilayer. Furthermore, an oxygen surfactant layer may be formed at one or more interfaces between adjoining (Co/Ni)X layers in the multilayer stack. Annealing at temperatures between 180° C. and 400° C. also increases Hc but the upper limit depends on whether the magnetic device is MAMR, MRAM, a hard bias structure, or a perpendicular magnetic medium.Type: GrantFiled: May 28, 2010Date of Patent: December 30, 2014Assignee: Headway Technologies, Inc.Inventors: Kunliang Zhang, Min Li, Yuchen Zhou
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Patent number: 8911888Abstract: Magnetic memories and methods are disclosed. A magnetic memory as described herein includes a plurality of stacked data storage layers to form a three-dimensional magnetic memory. The data storage layers are each formed from a multi-layer structure. At ambient temperatures, the multi-layer structures exhibit an antiparallel coupling state with a near zero net magnetic moment. At higher transition temperatures, the multi-layer structures transition from the antiparallel coupling state to a parallel coupling state with a net magnetic moment. At yet higher temperatures, the multi-layer structure transitions from the antiparallel coupling state to a receiving state where the coercivity of the multi-layer structures drops below a particular level so that magnetic fields from write elements or neighboring data storage layers may imprint data into the data storage layer.Type: GrantFiled: December 16, 2007Date of Patent: December 16, 2014Assignee: HGST Netherlands B.V.Inventors: Olav Hellwig, Bruce D. Terris, Jan-Ulrich Thiele
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Publication number: 20140363699Abstract: A current-perpendicular-to-plane magnetoresistive read sensor includes a stack of layers extending along a stacking direction, and an edge surface parallel to the stacking direction that forms at least part of a bearing surface of the read sensor, the bearing surface designed to face a recording medium. The stack of layers includes a first contact layer, a ferromagnetic free layer whose magnetic orientation varies according to an applied magnetic field, above the first contact layer, a non-magnetic layer above the ferromagnetic layer, a ferromagnetic spin injection layer above the non-magnetic layer, and a second contact layer above the spin injection layer, such that a current can flow between the second contact layer and the first contact layer along a current-perpendicular-to-plane direction, parallel to the stacking direction. The stack of layers further includes a series of structures extending along a direction parallel to the bearing surface and perpendicular to the stacking direction.Type: ApplicationFiled: June 2, 2014Publication date: December 11, 2014Applicant: International Business Machines CorporationInventors: Giovanni Cherubini, Simeon Furrer, Jens Jelitto, Mark A. Lantz
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Publication number: 20140356648Abstract: A stack having a seed layer structure with a first part having a first cross-track width and a free layer deposited over the seed layer structure and with a second cross-track width, wherein the first cross-track width is greater than the second cross-track width. In one implementation, the seed layer structure further comprises an antiferromagnetic (AFM) layer and a synthetic antiferromagnetic (SAF) layer. In one alternate implementation, the cross-track width of the seed layer structure is substantially equal to the combined cross-track width of the free layer and cross-track width of two permanent magnets.Type: ApplicationFiled: August 19, 2014Publication date: December 4, 2014Applicant: SEAGATE TECHNOLOGY LLCInventors: Eric Walter Singleton, Jae-Young Yi, Konstantin Nikolaev, Victor Boris Sapozhnikov, Stacey Christine Wakeham, Shaun Eric McKinlay
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Publication number: 20140313617Abstract: A tunneling magnetoresistive sensor has an extended pinned layer wherein both the MgO spacer layer and the underlying ferromagnetic pinned layer extend beyond the back edge of the ferromagnetic free layer in the stripe height direction and optionally also beyond the side edges of the free layer in the trackwidth direction. A patterned photoresist layer with a back edge is formed on the sensor stack and a methanol (CH3OH)-based reactive ion etching (RIE) removes the unprotected free layer, defining the free layer back edge. The methanol-based RIE terminates at the MgO spacer layer without damaging the underlying reference layer. A second patterned photoresist layer may be deposited and a second methanol-based RIE may be performed if it is desired to have the reference layer also extend beyond the side edges of the free layer in the trackwidth direction.Type: ApplicationFiled: April 23, 2013Publication date: October 23, 2014Applicant: HGST Netherlands B.V.Inventor: Jordan Asher Katine
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Patent number: 8865326Abstract: A layered ferromagnetic structure is composed of a first ferromagnetic layer positioned over a substrate; a second ferromagnetic layer positioned over the first ferromagnetic layer; and a first non-magnetic layer placed between the first and second ferromagnetic layers. The top surface of the first ferromagnetic layer is in contact with the first non-magnetic layer. The first ferromagnetic layer includes a first orientation control buffer that exhibits an effect of enhancing crystalline orientation of a film formed thereon.Type: GrantFiled: July 12, 2010Date of Patent: October 21, 2014Assignee: NEC CorporationInventors: Yoshiyuki Fukumoto, Chuuji Igarashi
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Patent number: 8852761Abstract: Provided is a magnetic anisotropy multilayer including a plurality of CoFeSiB/Pt layers used in a magnetic random access memory. The magnetic anisotropy multilayer includes a first Pt/CoFeSiB layer, and a second Pt/CoFeSiB layer formed on the first Pt/CoFeSiB layer.Type: GrantFiled: April 29, 2013Date of Patent: October 7, 2014Assignee: Korea University FoundationInventors: Young Keun Kim, You-Song Kim, Byong-Sun Chun, Seung-Youb Han, Jang-Roh Rhee
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Patent number: 8852760Abstract: A boron or boron containing dusting layer such as CoB or FeB is formed along one or both of top and bottom surfaces of a free layer at interfaces with a tunnel barrier layer and capping layer to improve thermal stability while maintaining other magnetic properties of a MTJ stack. Each dusting layer has a thickness from 0.2 to 20 Angstroms and may be used as deposited, or at temperatures up to 400° C. or higher, or following a subsequent anneal at 400° C. or higher. The free layer may be a single layer of CoFe, Co, CoFeB or CoFeNiB, or may include a non-magnetic insertion layer. The resulting MTJ is suitable for STT-MRAM memory elements or spintronic devices. Perpendicular magnetic anisotropy is maintained in the free layer at temperatures up to 400° C. or higher. Ku enhancement is achieved and the retention time of a memory cell for STT-MRAM designs is increased.Type: GrantFiled: April 17, 2012Date of Patent: October 7, 2014Assignee: Headway Technologies, Inc.Inventors: Yu-Jen Wang, Witold Kula, Ru-Ying Tong, Guenole Jan
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Publication number: 20140287267Abstract: A TMR sensor with a free layer having a FL1/FL2/FL3 configuration is disclosed in which FL1 is FeCo or a FeCo alloy with a thickness between 2 and 15 Angstroms. The FL2 layer is made of CoFeB or a CoFeB alloy having a thickness from 2 to 10 Angstroms. The FL3 layer is from 10 to 100 Angstroms thick and has a negative ? to offset the positive ? from FL1 and FL2 layers and is comprised of CoB or a CoBQ alloy where Q is one of Ni, Mn, Tb, W, Hf, Zr, Nb, and Si. Alternatively, the FL3 layer may be a composite such as CoB/CoFe, (CoB/CoFe)n where n is ?2 or (CoB/CoFe)m/CoB where m is ?1. The free layer described herein affords a high TMR ratio above 60% while achieving low values for ? (<5×10?6), RA (1.5 ohm/?m2), and Hc (<6 Oe).Type: ApplicationFiled: June 6, 2014Publication date: September 25, 2014Inventors: Hui-Chuan Wang, Tong Zhao, Min Li, Kunliang Zhang
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Patent number: 8830735Abstract: A magnetic memory includes: a magnetization fixed layer having perpendicular magnetic anisotropy, a magnetization direction of the magnetization fixed layer being fixed; an interlayer dielectric; an underlayer formed on upper faces of the magnetization fixed layer and the interlayer dielectric; and a data recording layer formed on an upper face of the underlayer and having perpendicular magnetic anisotropy. The underlayer includes: a first magnetic underlayer; and a non-magnetic underlayer formed on the first magnetic underlayer. The first magnetic underlayer is formed with such a thickness that the first magnetic underlayer does not exhibit in-plane magnetic anisotropy in a portion of the first magnetic underlayer formed on the interlayer dielectric.Type: GrantFiled: November 23, 2011Date of Patent: September 9, 2014Assignee: Renesas Electronics CorporationInventors: Eiji Kariyada, Katsumi Suemitsu, Hironobu Tanigawa, Kaoru Mori, Tetsuhiro Suzuki, Kiyokazu Nagahara, Yasuaki Ozaki, Norikazu Ohshima
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Publication number: 20140242418Abstract: One embodiment of a magnetoresistive element comprises: a free ferromagnetic layer comprising a reversible magnetization direction directed substantially perpendicular to a film surface in its equilibrium state; a pinned ferromagnetic layer comprising a fixed magnetization direction directed substantially perpendicular to the film surface; a nonmagnetic tunnel barrier layer disposed between the free ferromagnetic layer and the pinned ferromagnetic layer and having a direct contact with the free and pinned ferromagnetic layers; a first nonmagnetic conductive layer disposed adjacent to and having a direct contact with a side of a free ferromagnetic layer opposite to the tunnel barrier layer; and a second nonmagnetic conductive layer disposed adjacent to a side of the pinned ferromagnetic layer opposite to the tunnel barrier layer, wherein the free ferromagnetic layer and the pinned ferromagnetic layers comprise at least one element selected from the group consisting of Fe, Co, and Ni, at least one element selecType: ApplicationFiled: May 8, 2014Publication date: August 28, 2014Inventor: Alexander Mikhailovich Shukh
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Publication number: 20140220385Abstract: The performance of an MR device has been improved by inserting one or more Magneto-Resistance Enhancing Layers (MRELs) into approximately the center of one or more of the magnetic layers such as an inner pinned (AP1) layer, spin injection layer (SIL), field generation layer (FGL), and a free layer. An MREL is a layer of a low band gap, high electron mobility semiconductor such as ZnO or a semimetal such as Bi. The MREL may further comprise a first conductive layer that contacts a bottom surface of the semiconductor or semimetal layer, and a second conductive layer that contacts a top surface of the semiconductor or semimetal layer.Type: ApplicationFiled: April 4, 2014Publication date: August 7, 2014Applicant: Headway Technologies, Inc.Inventors: Kunliang Zhang, Min Li, Yuchen Zhou
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Patent number: 8795856Abstract: A nickel thin film is formed, for example, to a thickness of 2 nm or more on a polyethylene naphthalate substrate by a vacuum evaporation method. A magnetoresistance effect element using ferromagnetic nano-junction is comprised by using two laminates each comprising a nickel thin film formed on a polyethylene naphthalate substrate, and joining these two laminates so that the nickel thin films cross to each other in such a manner that edges of the nickel thin films face each other.Type: GrantFiled: August 28, 2008Date of Patent: August 5, 2014Assignees: National University Corporation, Hokkaido UniversityInventors: Hideo Kaiju, Manabu Ishimaru, Yoshihiko Hirotsu, Akito Ono, Akira Ishibashi
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Patent number: 8790798Abstract: A magnetoresistive element (and method of fabricating the magnetoresistive element) that includes a free ferromagnetic layer comprising a first reversible magnetization direction directed substantially perpendicular to a film surface, a pinned ferromagnetic layer comprising a second fixed magnetization direction directed substantially perpendicular to the film surface, and a nonmagnetic insulating tunnel barrier layer disposed between the free ferromagnetic layer and the pinned ferromagnetic layer, wherein the free ferromagnetic layer, the tunnel barrier layer, and the pinned ferromagnetic layer have a coherent body-centered cubic (bcc) structure with a (001) plane oriented, and a bidirectional spin-polarized current passing through the coherent structure in a direction perpendicular to the film surface reverses the magnetization direction of the free ferromagnetic layer.Type: GrantFiled: April 12, 2012Date of Patent: July 29, 2014Inventor: Alexander Mikhailovich Shukh
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Patent number: 8790797Abstract: The spin injection source comprises a nonmagnetic conductor, an MgO film, and a ferromagnet, and injects spin from the ferromagnet to the nonmagnetic conductor. The MgO film is annealed at temperature of between 300° C. and 500° C. The annealing duration is preferably between 30 and 60 minutes. By annealing, the oxygen vacancies increases and the electric resistance of MgO film decreases. And thus the spin injection efficiency in the spin injection source improves.Type: GrantFiled: September 1, 2011Date of Patent: July 29, 2014Assignee: RIKENInventors: Yasuhiro Fukuma, Yoshichika Otani
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Publication number: 20140205862Abstract: Provided are a magneto resistive effect element with a stable magnetization direction perpendicular to a film plane and with a controlled magnetoresistance ratio, and a magnetic memory using the magneto resistive effect element. Ferromagnetic layers 106 and 107 of the magneto resistive effect element are formed from a ferromagnetic material containing at least one type of 3d transition metal such that the magnetoresistance ratio is controlled, and the film thickness of the ferromagnetic layers is controlled on an atomic layer level such that the magnetization direction is changed from a direction in the film plane to a direction perpendicular to the film plane.Type: ApplicationFiled: March 25, 2014Publication date: July 24, 2014Applicant: Tohoku UniversityInventors: Hideo Ohno, Shoji Ikeda, Fumihiro Matsukura, Masaki Endoh, Shun Kanai, Hiroyuki Yamamoto, Katsuya Miura
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Patent number: 8778515Abstract: Embodiments of the present invention provide a practical magneto-resistive effect element for CPP-GMR, which exhibits appropriate resistance-area-product and high magnetoresistance change ratio, and meets the demand for a narrow read gap. Certain embodiments of a magneto-resistive effect element in accordance with the present invention include a pinned ferromagnetic layer containing a first ferromagnetic film having a magnetization direction fixed in one direction, a free ferromagnetic layer containing a second ferromagnetic film having a magnetization direction varying in response to an external magnetic field, an intermediate layer provided between the pinned ferromagnetic layer and the free ferromagnetic layer, and a current confinement layer for confining a current. At least one of the pinned ferromagnetic layer or the free ferromagnetic layer includes a highly spin polarized layer.Type: GrantFiled: November 21, 2008Date of Patent: July 15, 2014Assignee: HGST Netherlands B.V.Inventors: Yo Sato, Katsumi Hoshino, Hiroyuki Hoshiya
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Patent number: 8766382Abstract: A free ferromagnetic data storage layer of an MRAM cell is coupled to a free ferromagnetic stabilization layer, which stabilization layer is directly electrically coupled to a contact electrode, on one side, and is separated from the free ferromagnetic data storage layer, on an opposite side, by a spacer layer. The spacer layer provides for the coupling between the two free layers, which coupling is one of: a ferromagnetic coupling and an antiferromagnetic coupling.Type: GrantFiled: January 27, 2011Date of Patent: July 1, 2014Assignee: Seagate Technology LLCInventors: Haiwen Xi, Kaizhong Gao, Dimitar V. Dimitrov, Song S. Xue
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Patent number: 8758909Abstract: A magnetoresistive element that includes a free ferromagnetic layer comprising a reversible magnetization directed substantially perpendicular to a film surface, a pinned ferromagnetic layer comprising a fixed magnetization directed substantially perpendicular to the film surface, and a tunnel barrier layer disposed between the free and pinned ferromagnetic layers, wherein the free and pinned layers contain at least one element selected from the group consisting of Fe, Co, and Ni, at least one element selected from the group consisting of V, Cr, and Mo, and at least one element selected from the group consisting of B, P, C, and Si, and wherein the free layer, the tunnel barrier layer, and the pinned layer have a coherent body-centered cubic structure with a (001) plane oriented, and a bidirectional spin-polarized current passing through the coherent structure in a direction perpendicular to the film surface reverses a magnetization direction of the free layer.Type: GrantFiled: April 20, 2012Date of Patent: June 24, 2014Inventor: Alexander Mikhailovich Shukh
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Patent number: 8758850Abstract: A spin transfer torque magnetic random access memory (STTMRAM) element and a method of manufacturing the same is disclosed having a free sub-layer structure with enhanced internal stiffness. A first free sub-layer is deposited, the first free sub-layer being made partially of boron (B), annealing is performed of the STTMRAM element at a first temperature after depositing the first free sub-layer to reduce the B content at an interface between the first free sub-layer and the barrier layer, the annealing causing a second free sub-layer to be formed on top of the first free sub-layer and being made partially of B, the amount of B of the second free sub-layer being greater than the amount of B in the first free sub-layer.Type: GrantFiled: September 21, 2011Date of Patent: June 24, 2014Assignee: Avalanche Technology, Inc.Inventors: Yuchen Zhou, Yiming Huai
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Publication number: 20140154529Abstract: A magnetic read transducer including a magnetoresistive sensor is described, as well as a fabrication method thereof. The magnetoresistive sensor includes a cap layer overlaying a free layer. The cap layer is situated with a first thickness to absorb boron from the free layer. The magnetoresistive sensor is annealed, and boron is diffused from the free layer and absorbed by the cap layer, improving the magnetic performance of the free layer. The cap layer thickness is then reduced to a second thickness, thereby reducing the shield-to-shield (SS) stack spacing of the magnetoresistive sensor and allowing for increased areal recording density.Type: ApplicationFiled: November 30, 2012Publication date: June 5, 2014Applicant: Western Digital (Fremont), LLCInventor: Western Digital (Fremont), LLC
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Publication number: 20140154528Abstract: A magnetic element may generally be configured at least with a magnetic stack having a multilayer barrier structure disposed between first and second ferromagnetic layers. The multilayer barrier structure can have a binary compound layer disposed between first and second alloy layers with the binary compound having a metal element and a second element where at least one alloy layer has the metal element and a third element dissimilar from the second element.Type: ApplicationFiled: November 30, 2012Publication date: June 5, 2014Applicant: SEAGATE TECHNOLOGY LLCInventors: Vijay Karthik Sankar, Mark William Covington
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Patent number: 8722211Abstract: A magnetic memory device may include a first ferromagnetic layer, a second ferromagnetic layer, and a tunnel barrier layer arranged on a substrate. The tunnel barrier layer may include a crystal structure and may be arranged between the first ferromagnetic layer and the second ferromagnetic layer. At least the first ferromagnetic layer may include a first layer in contact with the tunnel barrier layer and a second layer in contact with the first layer, and an orientation of the first layer with respect to the tunnel barrier layer may be greater than an orientation of the second layer with respect to the tunnel barrier layer.Type: GrantFiled: January 19, 2010Date of Patent: May 13, 2014Assignee: Samsung Electronics Co., Ltd.Inventors: Woojin Kim, Jangeun Lee, Sechung Oh, KyungTae Nam, Dae Kyom Kim, Junho Jeong
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Patent number: 8679577Abstract: A magnetic tunnel junction cell having a free layer, a ferromagnetic pinned layer, and a barrier layer therebetween. The free layer has a central ferromagnetic portion and a stabilizing portion radially proximate the central ferromagnetic portion. The construction can be used for both in-plane magnetic memory cells where the magnetization orientation of the magnetic layer is in the stack film plane and out-of-plane magnetic memory cells where the magnetization orientation of the magnetic layer is out of the stack film plane, e.g., perpendicular to the stack plane.Type: GrantFiled: September 12, 2012Date of Patent: March 25, 2014Assignee: Seagate Technology LLCInventors: Kaizhong Gao, Haiwen Xi
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Publication number: 20140063648Abstract: In a Spin Torque Oscillator (STO) comprising an underlayer, a first magnetic layer disposed on the underlayer, a non-magnetic intermediate layer disposed on the first magnetic layer, and a second magnetic layer disposed on the non-magnetic intermediate layer, the non-magnetic intermediate layer is a non-magnetic alloy containing 50 at % or more of at least one kind of element selected from a first group consisting of Cu, Ag, and Au, and further at least 0.1 at % or more in total of at least one kind of element selected from a second group consisting of Cu, Ag, Au, Cr, Ti, Zr, Hf, V, Nb, Ta, Ru, Os, Pd, Pt, Rh, and Ir that does not overlap with the element from the first group.Type: ApplicationFiled: August 6, 2013Publication date: March 6, 2014Applicant: HITACHI, LTD.Inventors: Yoshihiro SHIROISHI, Katsuro WATANABE, Yo SATO
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Patent number: 8623452Abstract: A spin toque transfer magnetic random access memory (STTMRAM) element and a method of manufacturing the same is disclosed having a free sub-layer structure with enhanced internal stiffness. A first free sub-layer is deposited, the first free sub-layer being made partially of boron (B), annealing is performed of the STTMRAM element at a first temperature after depositing the first free sub-layer to reduce the B content at an interface between the first free sub-layer and the barrier layer, the annealing causing a second free sub-layer to be formed on top of the first free sub-layer and being made partially of B, the amount of B of the second free sub-layer being greater than the amount of B in the first free sub-layer.Type: GrantFiled: December 10, 2010Date of Patent: January 7, 2014Assignee: Avalanche Technology, Inc.Inventor: Yuchen Zhou
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Patent number: 8625237Abstract: A magnetic reproduction head includes a lower magnetic shield layer, an upper magnetic shield layer, a magnetoresistive film formed between the lower and the upper magnetic shield layers, a refill film in an element height direction disposed in contact with a surface opposite a floating surface of the magnetoresistive film, and a refill film in a track width direction disposed on a side wall surface of the magnetoresistive film. The magnetoresistive film is a tunneling magnetoresistive film including a free layer, an insulating barrier layer, and a fixed layer. The insulating barrier layer is one of a magnesium oxide film, an aluminum oxide film, and a titanium oxide film which contains at least one of nitrogen and silicon.Type: GrantFiled: November 17, 2008Date of Patent: January 7, 2014Assignee: Hitachi, Ltd.Inventor: Tomio Iwasaki
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Patent number: 8609262Abstract: 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: GrantFiled: July 17, 2009Date of Patent: December 17, 2013Assignee: MagIC Technologies, Inc.Inventors: Cheng T. Horng, Ru-Ying Tong, Guangli Liu, Robert Beach, Witold Kula, Tai Min
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Patent number: 8586216Abstract: A large spin-polarized current can be provided. A single crystal MgO layer is grown on an Si single crystal substrate, being lattice-matched. Thereon, a ferromagnetic metal layer is grown. Growth plane of MgO layer formed on (100) plane of Si single crystal substrate is (100) plane. At interface between Si single crystal substrate and MgO layer, Si (100) [110] and MgO (100) [100] directions are parallel. FIG. 2(A) shows Si (100) plane, FIG. 2(B) MgO (100) plane, and FIG. 2(C) the state of these two planes being lattice-matched. Si (100) plane in FIG. 2(A) is constituted by Si atoms 111 alone, while MgO (100) plane in FIG. 2(B) is constituted by Mg atoms 121 and oxygen (O) atoms 122. MgO (100) plane is grown on Si (100) plane, and as shown in FIG. 2(C), Si (100) [110] and MgO (100) [100] directions are parallel at the interface.Type: GrantFiled: December 13, 2011Date of Patent: November 19, 2013Assignees: Akita Prefecture, TDK CorporationInventor: Toshio Suzuki
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Publication number: 20130288076Abstract: A stack having a seed layer structure with a first part having a first cross-track width and a free layer deposited over the seed layer structure and with a second cross-track width, wherein the first cross-track width is greater than the second cross-track width. In one implementation, the seed layer structure further comprises an antiferromagnetic (AFM) layer and a synthetic antiferromagnetic (SAF) layer. In one alternate implementation, the cross-track width of the seed layer structure is substantially equal to the combined cross-track width of the free layer and cross-track width of two permanent magnets.Type: ApplicationFiled: April 30, 2012Publication date: October 31, 2013Applicant: SEAGATE TECHNOLOGY LLCInventors: Eric Walter Singleton, Jae-Young Yi, Konstantin Nikolaev, Victor Boris Sapozhnikov, Stacey Christine Wakeham, Shaun Eric McKinlay
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Patent number: 8557407Abstract: A high performance TMR sensor is fabricated by incorporating a tunnel barrier having a Mg/MgO/Mg configuration. The 4 to 14 Angstroms thick lower Mg layer and 2 to 8 Angstroms thick upper Mg layer are deposited by a DC sputtering method while the MgO layer is formed by a NOX process involving oxygen pressure from 0.1 mTorr to 1 Torr for 15 to 300 seconds. NOX time and pressure may be varied to achieve a MR ratio of at least 34% and a RA value of 2.1 ohm-um2. The NOX process provides a more uniform MgO layer than sputtering methods. The second Mg layer is employed to prevent oxidation of an adjacent ferromagnetic layer. In a bottom spin valve configuration, a Ta/Ru seed layer, IrMn AFM layer, CoFe/Ru/CoFeB pinned layer, Mg/MgO/Mg barrier, CoFe/NiFe free layer, and a cap layer are sequentially formed on a bottom shield in a read head.Type: GrantFiled: August 6, 2010Date of Patent: October 15, 2013Assignee: Headway Technologies, Inc.Inventors: Tong Zhao, Kunliang Zhang, Hui Chuan Wang, Yu-Hsia Chen, Min Li