Detail Of Free Layer Or Additional Film For Affecting Or Biasing The Free Layer Patents (Class 360/324.12)
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Patent number: 8427790Abstract: A thin film magnetic head includes a magnetoresistive element having a recording-medium-facing-surface which is to be faced with a magnetic recording medium; a magnetic bias layer located on a side opposite to the recording-medium-facing-surface of the magnetoresistive element, and applying a bias magnetic field to the magnetoresistive element in a direction orthogonal to the recording-medium-facing-surface; and a resistive film pattern having the recording-medium-facing-surface, the resistive film pattern being located side by side with the magnetoresistive element in a track-width direction.Type: GrantFiled: June 30, 2008Date of Patent: April 23, 2013Assignee: TDK CorporationInventors: Kei Hirata, Kazuki Sato, Yohei Koyanagi, Takayasu Kanaya, Takeo Kagami
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Patent number: 8421545Abstract: Oscillators and methods of operating the same, the oscillators include a pinned layer having a fixed magnetization direction, a first free layer over the pinned layer, and a second free layer over the first free layer. The oscillators are configured to generate a signal using precession of a magnetic moment of at least one of the first and second free layers.Type: GrantFiled: May 3, 2011Date of Patent: April 16, 2013Assignee: Samsung Electronics Co., Ltd.Inventors: Kwang-seok Kim, Sung-chul Lee, Kee-won Kim, Sun-ae Seo, Ung-hwan Pi
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Patent number: 8402635Abstract: A method of manufacturing a magnetic head, including a magneto resistance effect (MR) element that reads a magnetic recording medium, is disclosed. A multilayer film is formed on a shield layer. Unnecessary portions of the multilayer film are removed from both sides of the MR element in a first direction orthogonal to a lamination direction of the multilayer film and parallel to the MR element surface facing the magnetic recording medium. An insulating layer is formed on a surface exposed by removal of the unnecessary portions. An integrated soft magnetic layer covering both sides of the MR element in the first direction and an upper side of the MR element is formed, thereby configuring a second shield layer. An anisotropy application layer is formed on the second shield layer, thereby providing exchange anisotropy to the soft magnetic layer, and magnetizing the soft magnetic layer in a predetermined direction.Type: GrantFiled: March 21, 2011Date of Patent: March 26, 2013Assignee: TDK CorporationInventors: Naomichi Degawa, Takumi Yanagisawa, Satoshi Miura, Yoshikazu Sawada, Takahiko Machita, Kenzo Makino, Takekazu Yamane, Shohei Kawasaki
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Patent number: 8400738Abstract: An apparatus and associated method may be used to provide a data sensing element capable of detecting changes in magnetic states. Various embodiments of the present invention are generally directed to a magnetically responsive lamination of layers and [a] means for generating a high magnetic moment region proximal to an air bearing surface (ABS) and a low magnetic moment region proximal to a hard magnet.Type: GrantFiled: April 25, 2011Date of Patent: March 19, 2013Assignee: Seagate Technology LLCInventors: Mark William Covington, Qing He, Thomas Roy Boonstra
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Patent number: 8395867Abstract: A magnetic sensor has at least a free sub-stack, a reference sub-stack and a front shield. The free sub-stack has a magnetization direction substantially perpendicular to the planar orientation of the layer and extends to an air bearing surface. The reference sub-stack has a magnetization direction substantially perpendicular to the magnetization direction of the free sub-stack. The reference sub-stack is recessed from the air bearing surface and a front shield is positioned between the reference sub-stack and the air bearing surface.Type: GrantFiled: March 16, 2009Date of Patent: March 12, 2013Inventors: Dimitar Velikov Dimitrov, Zheng Gao, Wonjoon Jung, Sharat Batra, Olle Gunnar Heinonen
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Patent number: 8385025Abstract: A current-perpendicular-to-the-plane (CPP) magnetoresistive (MR) sensor has an improved seed layer structure for the ferromagnetic hard (high coercivity) bias layer that is used to longitudinally bias the sensor's free ferromagnetic layer. The seed layer structure is a trilayer consisting of a first seed layer of tantalum (Ta), a second seed layer of one or both titanium (Ti) and Ti-oxide on and in contact with the Ta layer, and a third seed layer of tungsten (W) on and in contact with the second seed layer.Type: GrantFiled: December 15, 2010Date of Patent: February 26, 2013Assignee: HGST Netherlands B.V.Inventors: Stefan Maat, Alexander M. Zeltser
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Patent number: 8385027Abstract: A composite free layer having a FL1/insertion/FL2 configuration is disclosed for achieving high dR/R, low RA, and low ? in TMR or GMR sensors. Ferromagnetic FL1 and FL2 layers have (+) ? and (?) ? values, respectively. FL1 may be CoFe, CoFeB, or alloys thereof with Ni, Ta, Mn, Ti, W, Zr, Hf, Tb, or Nb. FL2 may be CoFe, NiFe, or alloys thereof with Ni, Ta, Mn, Ti, W, Zr, Hf, Tb, Nb, or B. The thin insertion layer includes at least one magnetic element such as Co, Fe, and Ni, and at least one non-magnetic element selected from Ta, Ti, W, Zr, Hf, Nb, Mo, V, Cr, or B. In a TMR stack with a MgO tunnel barrier, dR/R>60%, ?˜1×10?6, and RA=1.2 ohm-um2 when FL1 is CoFe/CoFeB/CoFe, FL2 is CoFe/NiFe/CoFe, and the insertion layer is CoTa or CoFeBTa.Type: GrantFiled: October 19, 2011Date of Patent: February 26, 2013Assignee: Headway Technologies, Inc.Inventors: Tong Zhao, Hui-Chuan Wang, Min Li, Kunliang Zhang
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Patent number: 8379351Abstract: An example magneto-resistance effect element includes a fixed magnetization layer of which a magnetization is substantially fixed in one direction; a free magnetization layer of which a magnetization is rotated in accordance with an external magnetic field and which is formed opposite to the fixed magnetization layer; and a spacer layer including a current confining layer with an insulating layer and a conductor to pass a current through the insulating layer in a thickness direction thereof and which is located between the fixed magnetization layer and the free magnetization layer. A thin film layer is located on a side opposite to the spacer layer relative to the free magnetization layer and a functional layer containing at least one element selected from the group consisting of Si, Mg, B, Al is formed in or on at least one of the fixed magnetization layer, the free magnetization layer and the thin film layer.Type: GrantFiled: March 11, 2008Date of Patent: February 19, 2013Assignees: Kabushiki Kaisha Toshiba, TDK CorporationInventors: Yoshihiko Fuji, Hideaki Fukuzawa, Hiromi Yuasa, Kunliang Zhang, Min Li, Michiko Hara, Yoshinari Kurosaki
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Patent number: 8375565Abstract: A method fabricates a transducer having an air-bearing surface (ABS). The method includes providing at least one near-field transducer (NFT) film and providing an electronic lapping guide (ELG) film substantially coplanar with a portion of the at least one NFT film. The method also includes defining a disk portion of an NFT from the portion of the at least one NFT film and at least one ELG from the ELG film. The disk portion corresponds to a critical dimension of the NFT from an ABS location. The method also includes lapping the at least one transducer. The lapping is terminated based on a signal from the ELG.Type: GrantFiled: May 28, 2010Date of Patent: February 19, 2013Assignee: Western Digital (Fremont), LLCInventors: Yufeng Hu, Zhongyan Wang, Jinshan Li
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Patent number: 8347487Abstract: A fabricating method of a magnetoresistance sensor is provided with cost effective and process flexibility features. Firstly, a substrate is provided. Then, at least one magnetoresistance structure and at least one bonding pad are formed over the substrate, wherein the bonding pad is electrically connected with the magnetoresistance structure. Then, a passivation layer is formed over the magnetoresistance structure and the bonding pad. Then, a magnetic shielding and concentrator structure is formed over the passivation layer at a location corresponding to the magnetoresistance structure. Finally, bonding pad openings is formed on the passivation layer by patterned polyimide, thereby exposing the bonding pad. After bonding pad was opened, the patterned polyimide can be removed or retained as an additional protection layer.Type: GrantFiled: June 30, 2011Date of Patent: January 8, 2013Assignee: Voltafield Technology CorporationInventors: Fu-Tai Liou, Chih-Chien Liang, Chien-Min Lee
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Patent number: 8351164Abstract: An example magnetoresistive element includes a first magnetic layer whose magnetization direction is substantially pinned toward one direction; a second magnetic layer whose magnetization direction is changed in response to an external magnetic field; and a spacer layer. At least one of the first magnetic layer and the second magnetic layer includes a magnetic compound layer including a magnetic compound that is expressed by M1aM2bOc (where 5?a?68, 10?b?73, and 22?c?85). M1 is at least one element selected from the group consisting of Co, Fe, and Ni. M2 is at least one element selected from the group consisting of Ti, V, and Cr.Type: GrantFiled: April 24, 2012Date of Patent: January 8, 2013Assignee: Kabushiki Kaisha ToshibaInventors: Yoshihiko Fuji, Hideaki Fukuzawa, Hiromi Yuasa
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Patent number: 8351165Abstract: A current-perpendicular-to-the-plane spin-valve (CPP-SV) magnetoresistive sensor has a ferromagnetic alloy comprising Co, Fe and Ge in the sensor's free layer and/or pinned layer and a spacer layer of Ag, Cu or a AgCu alloy between the free and pinned layers. The sensor may be a simple pinned structure, in which case the pinned layer may be formed of the CoFeGe ferromagnetic alloy. Alternatively, the sensor may have an AP-pinned layer structure, in which case the AP2layer may be formed of the CoFeGe ferromagnetic alloy. The Ge-containing alloy comprises Co, Fe and Ge, wherein Ge is present in the alloy in an amount between about 20 and 40 atomic percent, and wherein the ratio of Co to Fe in the alloy is between about 0.8 and 1.2.Type: GrantFiled: October 13, 2010Date of Patent: January 8, 2013Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Matthew J. Carey, Jeffrey R. Childress, Stefan Maat
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Patent number: 8345389Abstract: A magnetoresistive element includes a first ferromagnetic layer, a second ferromagnetic layer, a nonmagnetic layer, a first metal layer, a second metal layer, a first electrode, and a second electrode. The nonmagnetic layer is provided between the first ferromagnetic layer and the second ferromagnetic layer. The first metal layer includes Au and is provided so that the first ferromagnetic layer is sandwiched between the nonmagnetic layer and the first metal layer. The second metal layer includes a CuNi alloy, and is provided so that the first metal layer is sandwiched between the first ferromagnetic layer and the second metal layer. In addition, magnetization of either one of the first ferromagnetic layer and the second ferromagnetic layer is fixed in a direction. Magnetization of the other is variable in response to an external field. At least one of the first ferromagnetic layer and the second ferromagnetic layer includes a half metal.Type: GrantFiled: September 10, 2010Date of Patent: January 1, 2013Assignee: Kabushiki Kaisha ToshibaInventors: Hiromi Yuasa, Shuichi Murakami, Yoshihiko Fuji, Hideaki Fukuzawa
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Patent number: 8345390Abstract: An MR element according to the present invention has the superior effects that further improve an MR ratio because a structure of a spacer layer 40 is configured of a certain three-layer structure with certain materials, and at least one of a first ferromagnetic layer 30 and a second ferromagnetic layer 50 contains a certain amount of an element selected from the group of nitrogen (N), carbon (C), and oxygen (O).Type: GrantFiled: February 26, 2009Date of Patent: January 1, 2013Assignee: TDK CorporationInventors: Yoshihiro Tsuchiya, Shinji Hara, Tsutomu Chou, Hironobu Matsuzawa
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Patent number: 8339752Abstract: In one embodiment, a magnetic head includes a magnetoresistive free layer, wherein a width of the free layer nearest an air bearing surface (ABS) is less than a width of the free layer at a point away from the ABS in a track width direction, with the magnetic head being configured to pass a sense current in a direction perpendicular to a plane of deposition of the free layer. In another embodiment, a method includes forming a magnetoresistive film above a shield, forming a masking layer above the magnetoresistive film, patterning the masking layer such that it exposes portions of the magnetoresistive film, wherein the masking layer defines an area which is narrow near an area that forms an ABS side of a free layer and wider at an area away from the ABS, and removing the exposed portions of the magnetoresistive film to form the free layer.Type: GrantFiled: September 26, 2011Date of Patent: December 25, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Masashi Hattori, Koichi Nishioka, Koji Sakamoto, Tsutomu Yasuda, Hideki Mashima
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Patent number: 8336194Abstract: A method of fabricating a tunneling magnetoresistance (TMR) reader is disclosed. A TMR structure comprising at least one ferromagnetic layer and at least one nonmagnetic insulating layer is provided. A first thermal annealing process on the TMR structure is performed. A reader pattern definition process performed on the TMR structure to obtain a patterned TMR reader. A second thermal annealing process is performed on the patterned TMR reader.Type: GrantFiled: November 3, 2009Date of Patent: December 25, 2012Assignee: Western Digital (Fremont), LLCInventors: Lu Yuan, Jian X. Shen, Geoffrey W. Anderson, Christopher Ng
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Patent number: 8339750Abstract: A magnetic sensor comprises a nonmagnetic conductive layer, a free magnetization layer disposed on a first part of the nonmagnetic conductive layer, a fixed magnetization layer disposed on a second part of the nonmagnetic conductive layer different from the first part, upper and lower first magnetic shield layers opposing each other through the nonmagnetic conductive layer and free magnetization layer interposed therebetween, upper and lower second magnetic shield layers opposing each other through the nonmagnetic conductive layer and fixed magnetization layer interposed therebetween, and an electrically insulating layer disposed between the lower second magnetic shield layer and the nonmagnetic conductive layer, while the lower first magnetic shield layer is arranged closer to the nonmagnetic conductive layer than is the lower second magnetic shield layer.Type: GrantFiled: May 26, 2009Date of Patent: December 25, 2012Assignee: TDK CorporationInventor: Tomoyuki Sasaki
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Patent number: 8339753Abstract: A magnetic read head having a novel magnetic bias structure that provides improved magnetic biasing for improved free layer robustness and reduced Barkhausen noise. The bias structure includes hard magnetic layer formed over first and second under-layers. At least a portion of the first under-layer is formed as discrete islands of material, and the second under-layer is formed over the first under-layer. The first under-layer has a thickness of 0.25 to 0.75 nm. The novel seed layer structure causes hard magnetic layer to have a magnetic anisotropy that is substantially parallel with the free layer of the sensor stack even in regions adjacent to the sensor stack.Type: GrantFiled: October 11, 2011Date of Patent: December 25, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Norihiro Okawa, Koji Sakamoto, Koji Okazaki
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Patent number: 8338004Abstract: The present invention provides a magnetic tunnel junction structure, including a first magnetic layer having a fixed magnetization direction and a second magnetic layer having a reversible magnetization direction. A non-magnetic layer is formed between the first magnetic layer and the second magnetic layer and a third magnetic layer allows the magnetization direction of the second magnetic layer to be inclined with respect to a plane of the second magnetic layer by a magnetic coupling to the second magnetic layer with a vertical magnetic anisotropic energy thereof larger than a horizontal magnetic anisotropic energy thereof. A crystal-structure separation layer is formed between the second magnetic layer and the third magnetic layer for separating a crystal orientation between the second and the third magnetic layers.Type: GrantFiled: October 29, 2009Date of Patent: December 25, 2012Assignee: Korea Institute of Science and TechnologyInventors: Kyung Ho Shin, Byoung Chul Min
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Patent number: 8335058Abstract: A magnetic sensor includes a reference layer having a first magnetization direction and a free layer assembly having an effective magnetization direction substantially perpendicular to the first magnetization direction and substantially perpendicular to a plane of each layer of the free layer assembly. A spacer layer is between the reference layer and the free layer, and a signal enhancement layer is exchange coupled to the free layer assembly on a side opposite the spacer layer.Type: GrantFiled: March 15, 2011Date of Patent: December 18, 2012Assignee: Seagate Technology LLCInventors: Song S. Xue, Zheng Gao, Shaoping Li, Kaizhong Gao, Dimitar V. Dimitrov, Konstantin Nikolaev, Patrick J. Ryan
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Patent number: 8335057Abstract: According to one embodiment, a CPP magnetoresistive head includes a magnetoresistive film comprising a free layer above a non-magnetic intermediate layer and a fixed layer below the non-magnetic intermediate layer, wherein the magnetoresistive film is between a lower magnetic shield layer and an upper magnetic shield layer. The CPP magnetoresistive head also includes a domain control film on each side of the magnetoresistive film, wherein a sense current flows through the magnetoresistive film between the upper magnetic shield layer and the lower magnetic shield layer. The CPP magnetoresistive head also includes a high heat conductivity layer, and a heat dissipation layer having a high heat conductivity and a low linear expansion coefficient, the heat dissipation layer being disposed at the back in a device height direction of the magnetoresistive film and on each side of the domain control film.Type: GrantFiled: August 5, 2009Date of Patent: December 18, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Masahiro Osugi, Takayoshi Ohtsu, Shigeo Fujita, Katsuro Watanabe, Koji Kataoka
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Patent number: 8335056Abstract: Read sensors and associated methods of fabrication are disclosed. A read sensor as disclosed herein includes a first shield, a sensor stack including an antiparallel (AP) free layer, and insulating material disposed on the sensor stack. A aperture is formed through the insulating material above the sensor stack so that a subsequently deposited second shield is electrically coupled to the sensor stack through the aperture. The width of the aperture controls the current density that is injected into the top of the sensor stack. Also, hard bias structures may be formed to be electrically coupled to the sensor stack. The electrical coupling of the sensor stack and the hard bias structures allows current to laterally spread out as it passes through the sensor stack, and hence, provides a non-uniform current density.Type: GrantFiled: December 16, 2007Date of Patent: December 18, 2012Assignee: HGST Netherlands, B.V.Inventors: Hamid Balamane, Jeffrey R. Childress, Robert E. Fontana, Jr., Jordan A. Katine, Neil Smith
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Patent number: 8331063Abstract: An MR element in a CPP-GMR structure includes a first ferromagnetic layer, a spacer layer that is epitaxially formed on the first ferromagnetic layer, a second ferromagnetic layer that is located on the spacer layer, and that is laminated with the first ferromagnetic layer to sandwich the spacer layer. A sense current flows along a lamination direction of the first and second ferromagnetic layers. Angle of magnetization directions of the first ferromagnetic layer and the second ferromagnetic layer relatively change due to an externally applied magnetic field.Type: GrantFiled: July 10, 2009Date of Patent: December 11, 2012Assignee: TDK CorporationInventors: Shinji Hara, Tsutomu Chou, Yoshihiro Tsuchiya, Hironobu Matsuzawa
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Patent number: 8316527Abstract: The method provides a magnetoresistive device. The magnetoresistive device is formed from a plurality of magnetoresistive layers. The method includes providing a mask. The mask covers a first portion of the magnetoresistive element layers in at least one device area. The magnetoresistive element(s) are defined using the mask. The method includes depositing hard bias layer(s). The method also includes providing a hard bias capping structure on the hard bias layer(s). The hard bias capping structure includes a first protective layer and a planarization stop layer. The first protective layer resides between the planarization stop layer and the hard bias layer(s). The method also includes performing a planarization. The planarization stop layer is configured for the planarization.Type: GrantFiled: April 1, 2008Date of Patent: November 27, 2012Assignee: Western Digital (Fremont), LLCInventors: Liubo Hong, Honglin Zhu
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Patent number: 8315019Abstract: A method and system for providing a magnetic transducer is described. The method and system include providing a magnetoresistive structure having a plurality of sides. At least one oxidation buffer layer covers at least the plurality of sides. The method and system also include providing at least one oxide layer after the oxidation buffer layer is provided. The oxide layer(s) reside between the sides and the oxidation buffer layer(s).Type: GrantFiled: March 31, 2009Date of Patent: November 20, 2012Assignee: Western Digital (Fremont), LLCInventors: Ming Mao, Wei Zhang, Mahendra Pakala
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Patent number: 8310792Abstract: A magnetoresistive element (MR element) for reading a change in a magnetic field of a magnetic recording medium includes first and second electrode layers for providing a sensing current, which are perpendicular to an air bearing surface (ABS) facing the magnetic recording medium, first and second free layers which have a magnetization direction which changes in accordance with an external magnetic field, and a spacer layer composed of non-magnetic material. A ratio of a representative width and a representative length of each of the first and second free layers is at least 2 to 1, to thereby provide initial magnetizations along a direction of the representative length of each of the first and second free layers.Type: GrantFiled: November 15, 2007Date of Patent: November 13, 2012Assignee: TDK CorporationInventors: Naoki Ohta, Hiroshi Yamazaki
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Patent number: 8307539Abstract: A method for modeling devices in a wafer comprises the step of providing the wafer comprising a first plurality of devices having a track width and a first stripe height, a second plurality of devices having the track width and a second stripe height, and a third plurality of devices having the track width and a third stripe height. The method further comprises the steps of measuring resistance values for the first, second and third plurality of devices to obtain a data set correlating a stripe height and a resistance value for each of the first, second and third plurality of devices, and estimating a linear relationship between resistance and inverse stripe height for the first, second and third plurality of devices based on the data set.Type: GrantFiled: September 30, 2009Date of Patent: November 13, 2012Assignee: Western Digital (Fremont), LLCInventors: Steven C. Rudy, Eric R. Mckie, Mark D. Moravec
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Patent number: 8310791Abstract: A magnetoresistive effect element is structured in the manner that the antiferromagnetic layer interposed between the upper and lower shields is eliminated and the antiferromagnetic layer is positioned in a so-called shield layer. Therefore, it is realized to solve a pin reversal problem and to allow narrower tracks and narrower read gaps.Type: GrantFiled: March 13, 2009Date of Patent: November 13, 2012Assignee: TDK CorporationInventors: Takahiko Machita, Tomohito Mizuno, Koji Shimazawa, Tsutomu Chou, Daisuke Miyauchi, Yoshihiro Tsuchiya, Shinji Hara, Toshiyuki Ayukawa
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Patent number: 8296930Abstract: A method for manufacturing a magnetoresistive sensor that results in the sensor having a very flat top magnetic shield. The process involves depositing a plurality of sensor layers and then depositing a thin high density carbon CMP stop layer over the sensor layers and forming a mask over the CMP stop layer. An ion milling is performed to define the sensor. Then a thin insulating layer and magnetic hard bias layer are deposited. A chemical mechanical polishing is performed to remove the mask and a reactive ion etching is performed to remove the remaining carbon CMP stop layer. Because the CMP stop layer is very dense and hard, it can be made very thin. This means that when it is removed by reactive ion etching, there is very little notching over the sensor, thereby allowing the upper shield to be very thin.Type: GrantFiled: December 22, 2009Date of Patent: October 30, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Shin Funada, Quang Le, Thomas L. Leong, Jui-Lung Li, Chang-Man Park, Ning Shi, Hicham M. Sougrati
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Patent number: 8295015Abstract: The invention is devised to provide a magnetoresistive element that is hardly susceptible to harmful influence of unnecessary magnetic fields and noise of heat even when reduction in size is achieved to be adaptable to higher recording density, and therefore that is excellent in operational reliability. The magnetoresistive element includes a stacked structure including, in order: a magnetically pinned layer whose magnetization direction is fixed in a given direction; a non-magnetic layer; a magnetically free layer whose magnetization direction changes according to an external magnetic field; and an antiferromagnetic bias layer exchange-coupled with the magnetically free layer. The exchange-coupling magnetic field between the magnetically free layer and the antiferromagnetic bias layer is smaller than a saturation magnetic field of the magnetically free layer.Type: GrantFiled: February 6, 2009Date of Patent: October 23, 2012Assignee: TDK CorporationInventors: Naoki Ohta, Hiroshi Yamazaki, Kosuke Tanaka, Takayasu Kanaya, Kei Hirata
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Patent number: 8289661Abstract: A CPP-GMR spin valve having a CoFe/NiFe composite free layer is disclosed in which Fe content of the CoFe layer ranges from 20 to 70 atomic % and Ni content in the NiFe layer varies from 85 to 100 atomic % to maintain low Hc and ?S values. A higher than normal Fe content in the CoFe layer improves the MR ratio by ?16% compared with conventional CoFe/NiFe free layers in which the Fe content in CoFe is typically <20 atomic % and the Ni content in NiFe is <85 atomic %. The CPP-GMR performance may also be optimized by incorporating a confining current path layer in the copper spacer between the pinned layer and free layer. For a pinned layer with an AP2/Ru/AP1 configuration, the spin valve performance is further improved by an AP1 layer comprised of a lamination of CoFe and Cu layers as in [CoFe/Cu]2/CoFe.Type: GrantFiled: April 4, 2011Date of Patent: October 16, 2012Assignee: Headway Technologies, Inc.Inventors: Kunliang Zhang, Min Li, Yu-Hsia Chen, Chyu-Jiuh Torng
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Patent number: 8288023Abstract: 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: December 23, 2010Date of Patent: October 16, 2012Assignee: Seagate Technology LLCInventors: Kaizhong Gao, Haiwen Xi
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Patent number: 8274764Abstract: A magneto-resistive effect (MR) element includes a first magnetic layer and a second magnetic layer in which a relative angle of magnetization directions of the first and second magnetic layers changes according to an external magnetic field; and a spacer layer that is provided between the first magnetic layer and the second magnetic layer. The spacer layer contains gallium nitride (GaN) as a main component.Type: GrantFiled: March 10, 2009Date of Patent: September 25, 2012Assignee: TDK CorporationInventors: Shinji Hara, Yoshihiro Tsuchiya, Tsutomu Chou, Hironobu Matsuzawa
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Patent number: 8270125Abstract: A magnetoresistive tunnel junction sensor having improved free layer stability, as well as improved free sensitivity. The free layer is constructed to have a low magnetic coercivity which improves free layer sensitivity. The free layer is also constructed to have a negative magnetostriction which improves free layer stability by preventing the free layer from having an easy axis that is oriented perpendicular to the air bearing surface.Type: GrantFiled: December 18, 2007Date of Patent: September 18, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventor: Hardayal Singh Gill
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Patent number: 8270126Abstract: A method and system for providing a hard bias structure include providing a seed layer for a hard bias structure. The seed layer has a lattice constant and a natural growth texture. The method and system further include depositing the hard bias layer for the hard bias structure on the seed layer. The natural growth texture of the seed layer corresponds to a texture for the hard bias layer. The hard bias layer has a bulk lattice constant. Providing the seed layer includes forming a first plasma of a first deposition gas configured to expand the seed layer lattice constant if the bulk lattice constant is greater than the seed layer constant. Depositing the hard bias layer further includes forming a second plasma of a second deposition gas configured to expand the bulk lattice constant if the seed layer lattice constant is greater than the bulk lattice constant.Type: GrantFiled: June 16, 2008Date of Patent: September 18, 2012Assignee: Western Digital (Fremont), LLCInventors: Anup G. Roy, Mahendra Pakala
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Patent number: 8256095Abstract: An example method for manufacturing a magneto-resistance effect element includes forming a free magnetization layer and forming a spacer layer. The spacer layer is formed, for example, by forming a non-magnetic first metallic layer and forming a second metallic layer on a surface of the non-magnetic first metallic layer. A first irradiating process includes irradiating, onto the second metallic layer, first ions or plasma including at least one of oxygen and nitrogen and at least one selected from the group consisting of Ar, Xe, He, Ne, Kr, so as to convert the second metallic layer into an insulating layer and to form a non-magnetic metallic path penetrating through the insulating layer and containing elements of the non-magnetic first metallic layer. A second irradiating process includes irradiating second ions or plasma onto the insulating layer. A non-magnetic third metallic layer is formed on the non-magnetic metallic path.Type: GrantFiled: August 30, 2010Date of Patent: September 4, 2012Assignee: Kabushiki Kaisha ToshibaInventors: Hiromi Yuasa, Hideaki Fukuzawa, Yoshihiko Fuji
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Patent number: 8259420Abstract: A composite free layer having a FL1/insertion/FL2 configuration where a top surface of FL1 is treated with a weak plasma etch is disclosed for achieving enhanced dR/R while maintaining low RA, and low ? in TMR or GMR sensors. The weak plasma etch removes less than about 0.2 Angstroms of FL1 and is believed to modify surface structure and possibly increase surface energy. FL1 may be CoFe, CoFe/CoFeB, or alloys thereof with Ni, Ta, Mn, Ti, W, Zr, Hf, Tb, or Nb having a (+) ? value. FL2 may be CoFe, NiFe, or alloys thereof having a (?) ? value. The thin insertion layer includes at least one magnetic element such as Co, Fe, and Ni, and at least one non-magnetic element selected from Ta, Ti, W, Zr, Hf, Nb, Mo, V, Cr, or B. When CoFeBTa is selected as insertion layer, the CoFeB:Ta ratio is from 1:1 to 4:1.Type: GrantFiled: February 1, 2010Date of Patent: September 4, 2012Assignee: Headway Technologies, Inc.Inventors: Tong Zhao, Hui Chuan Wang, Min Li, Kunliang Zhang
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Patent number: 8254066Abstract: A method for determining a magnetic anisotropy of a free layer of a magnetoresistive sensor. The method includes forming a functional magnetoresistive sensor and also a test sensor on a wafer. The test sensor has a sensor stack that is identical to that of the functional sensor, however the test head does not have a magnetic bias structure for biasing the free layer. A series of tests can be performed to construct a transfer curve for the test sensor. This can then be used to determine a magnetic anisotropy of the test head, which also corresponds to a magnetic anisotropy of the functional head.Type: GrantFiled: December 30, 2008Date of Patent: August 28, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Yimin Hsu, Arley Cleveland Marley
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Patent number: 8240026Abstract: A method for manufacturing a magneto-resistive device. The magneto-resistive device is for reducing the deterioration in the characteristics of the device due to annealing. The magneto-resistive device has a magneto-resistive layer formed on one surface side of a base, and an insulating layer formed of two layers and deposited around the magneto-resistive layer. The layer of the insulating layer closest to the base is made of a metal or semiconductor oxide. This layer extends over end faces of a plurality of layers made of different materials from one another, which make up the magneto-resistive device, and is in contact with the end faces of the plurality of layers with the same materials.Type: GrantFiled: September 24, 2008Date of Patent: August 14, 2012Assignee: TDK CorporationInventors: Takeo Kagami, Tetsuya Kuwashima, Norio Takahashi
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Patent number: 8243398Abstract: A magneto-resistive (MR) device for reading at least one of a legacy data and a present data magnetically recorded on at least one legacy track and a least one present track, respectively, is provided. The device comprises first and second MR elements, and first, second, and third permanent magnets. The first MR read element is positioned between the first and the second permanent magnets to stabilize the first MR read element while reading the legacy data from the media. The second MR element is positioned adjacent to the second permanent magnet and configured to read the present data from the media. The third permanent magnet is positioned adjacent to the second MR element and opposite to the second permanent magnet. The second and the third permanent magnets cooperate with each other to stabilize the second MR read element while reading the present data from the media.Type: GrantFiled: June 18, 2008Date of Patent: August 14, 2012Assignee: Oracle America, Inc.Inventors: Charles C. Partee, John P. Nibarger
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Patent number: 8238063Abstract: A magnetic sensor assembly including first and second shields, and a sensor stack between the first and second shields. The sensor stack includes a seed layer adjacent the first shield, a cap layer adjacent the second shield, and a magnetic sensor between the seed layer and the cap layer, wherein at least one of the seed layer and the cap layer has a synthetic antiferromagnetic structure.Type: GrantFiled: July 7, 2009Date of Patent: August 7, 2012Assignee: Seagate Technology LLCInventors: Jiaoming Qiu, Hao Meng, Yonghua Chen
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Patent number: 8225487Abstract: A method according to one embodiment includes forming a mask above a thin film sensor stack; forming an electrically insulating layer above the mask and sensor stack, the insulating layer having a portion extending along a nonhorizontal end of the mask; selectively removing the insulating layer except for the portion thereof extending along the nonhorizontal end of the mask; removing portions of the sensor stack that are not covered by the mask and the portion of the insulating layer, wherein an end of the portion of the insulating layer positioned away from the mask is about aligned with a back end of the sensor stack after removing the portions thereof; and removing the mask.Type: GrantFiled: July 25, 2008Date of Patent: July 24, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Ying Hong, Edward Hin Pong Lee, Aron Pentek, David John Seagle
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Patent number: 8225489Abstract: An MR element includes a first exchange coupling shield layer, an MR stack, and a second exchange coupling shield layer that are arranged in this order from the bottom, and a nonmagnetic layer surrounding the MR stack. The MR stack includes a first free layer, a spacer layer, a second free layer, and a magnetic cap layer that are arranged in this order from the bottom. In the step of forming the MR stack and the nonmagnetic layer, a protection layer is formed on a layered film that will be the MR stack later, and a mask is then formed on the protection layer. Next, the layered film and the protection layer are etched using the mask and then the nonmagnetic layer is formed. After removal of the mask, the protection layer is removed by wet etching.Type: GrantFiled: March 26, 2010Date of Patent: July 24, 2012Assignee: TDK CorporationInventors: Daisuke Miyauchi, Takahiko Machita, Keita Kawamori
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Patent number: 8227099Abstract: This radio-frequency oscillator includes a magnetoresistive device in which a spin-polarized electric current flows. This device comprises a stack of at least a first so-called “anchored” magnetic layer having a fixed magnetization direction, a second magnetic layer, an amagnetic layer inserted between the above-mentioned two layers, intended to ensure magnetic decoupling of said layers. The oscillator also comprises means of causing a flow of electrons in said layers perpendicular to these layers and, if applicable, of applying an external magnetic field to the structure. The second magnetic layer has an excitation damping factor at least 10% greater than the damping measured in a simple layer of the same material having the same geometry for magnetic excitation having wavelengths equal to or less than the extent of the cone or cylinder of current that flows through the stack that constitutes the magnetoresistive device.Type: GrantFiled: April 23, 2008Date of Patent: July 24, 2012Assignees: Commissariat a l'Energie Atomique, Centre National de la Recherche ScientifiqueInventors: Bernard Dieny, Alina-Maria Deac-Renner
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Patent number: 8228644Abstract: A CPP spin-valve magnetic head, according to one embodiment includes a ferromagnetic free layer having a bias-point magnetization nominally oriented in a first direction; a ferromagnetic reference layer film having a bias-point magnetization nominally oriented in a second direction that is not orthogonal to the said first direction; and a tunnel barrier layer between the free and reference layers.Type: GrantFiled: January 26, 2012Date of Patent: July 24, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Jeffrey Robinson Childress, Neil Smith
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Patent number: 8223463Abstract: A magnetoresistive head which has a high head SNR by reducing generated mag-noise without deteriorating an output comprises, according to one embodiment, a magnetoresistive sensor having a laminated structure which includes an antiferromagnetic layer, a magnetization pinned layer, a non-magnetic intermediate layer, a magnetization free layer, and a magnetization stable layer arranged adjacent to the magnetization free layer. The magnetization stable layer comprises non-magnetic coupling layer, a first ferromagnetic stable layer, an antiparallel coupling layer, and a second ferromagnetic stable layer. A magnetization quantity of a first ferromagnetic stable layer and a second ferromagnetic stable layer are substantially equal, and the magnetization of the first ferromagnetic stable layer and the second ferromagnetic stable layer are magnetically coupled in the antiparallel direction from each other.Type: GrantFiled: October 15, 2009Date of Patent: July 17, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Hiroyuki Katada, Masato Shiimoto, Hiroyuki Hoshiya
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Patent number: 8223464Abstract: In one embodiment, a differential-type magnetic read head includes a differential-type magneto-resistive-effect film formed on a substrate, and a pair of electrodes for applying current in a direction perpendicular to a film plane of the film. The film includes a first and second stacked film, each having a pinned layer, an intermediate layer, and a free layer, with the second stacked film being formed on the first stacked film. A side face in a track width direction of the film is shaped to have an inflection point at an intermediate position in a thickness direction of the film, and the side face is shaped to be approximately vertical to the substrate in an upward direction of the substrate from the inflection point. Also, the side face is shaped to be gradually increased in track width as approaching the substrate in a downward direction of the substrate from the inflection point.Type: GrantFiled: November 9, 2009Date of Patent: July 17, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Kan Yasui, Masato Shiimoto, Takeshi Nakagawa, Hiroyuki Katada, Nobuo Yoshida, Hiroyuki Hoshiya
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Patent number: 8218270Abstract: A hard magnet biasing structure for a CPP-GMR or CPP-TMR read head for a magnetic recording disk drive is located between the two sensor shields and abutting the side edges of the sensor free layer. An insulating layer is located between the biasing structure and the lower shield and the side edges of the free layer. The biasing structure includes a seed layer of either Ir or Ru, a layer of ferromagnetic chemically-ordered FePt alloy hard bias layer on the seed layer, and a Ru or Ru/Ir capping layer on the FePt alloy hard bias layer. The FePt alloy has a face-centered-tetragonal structure with its c-axis generally in the plane of the layer. The relatively thin seed layer and capping layer allow the biasing structure to be made very thin while still permitting the FePt alloy hard bias layer to have high coercivity (Hc), a high remanent magnetization-thickness product (Mrt) and a high squareness (S=Mrt/Ms).Type: GrantFiled: March 31, 2011Date of Patent: July 10, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Alexander M. Zeltser, Stefan Maat
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Patent number: 8216703Abstract: A magnetic tunnel junction (MTJ) (10) employing a dielectric tunneling barrier (16), useful in magnetoresistive random access memories (MRAMs) and other devices, has a synthetic antiferromagnet (SAF) structure (14, 16), comprising two ferromagnetic (FM) layers (26, 41; 51, 58; 61, 68) separated by a coupling layer (38, 56, 66). Improved magnetoresistance (MR) ratio is obtained by providing a further layer (44, 46, 46?, 47, 52, 62), e.g. containing Ta, preferably spaced apart from the coupling layer (38, 56, 66) by a FM layer (41, 30-2, 54). The further layer (44, 46, 46?, 47, 52, 62) may be a Ta dusting layer (44) covered by a FM layer (30-2), or a Ta containing FM alloyed layer (46), or a stack (46?) of interleaved FM and N-FM layers, or other combination (47, 62). Furthering these benefits, another FM layer, e.g., CoFe, NiFe, (30, 30-1, 51, 61) is desirably provided between the further layer (44, 46, 46?, 47, 52, 62) and the tunneling barrier (16).Type: GrantFiled: February 21, 2008Date of Patent: July 10, 2012Assignee: Everspin Technologies, Inc.Inventors: Jijun Sun, Jon M. Slaughter
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Patent number: 8213131Abstract: A system in one embodiment includes a magnetic sensor having a free magnetic layer, a nanocrystalline seed layer formed on an insulative amorphous material; a chromium-containing underlayer formed on the seed layer; and a hard bias layer formed on the underlayer and separated from the sensor by the insulative amorphous material. A method according to a further embodiment includes forming an amorphous insulative layer encapsulating a sensor stack; forming a nanocrystalline seed layer on the amorphous insulative material; forming a chromium-containing underlayer on the seed layer; and forming a hard bias layer on the underlayer. Additional systems and methods are presented.Type: GrantFiled: July 1, 2008Date of Patent: July 3, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Yongjian Sun, Brian R. York