Detail Of Pinned Film Or Additional Film For Affecting Or Biasing The Pinned Film Patents (Class 360/324.11)
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Patent number: 7499247Abstract: A magnetoresistive sensor comprises stacked layers. The stacked layers comprises a first magnetic layer, a second non-magnetic intermediate layer, and a second magnetic layer in which a direction of magnetization is variable depending on an external magnetic field. The first magnetic layer, the second non-magnetic intermediate layer, and the second magnetic layer are stacked in this order to form the stacked layers. The first magnetic layer has a first ferromagnetic layer in which a direction of magnetization is pinned relative to the external magnetic field, a first non-magnetic intermediate layer, and a second ferromagnetic layer in which a direction of magnetization is pinned in a direction opposite to the direction of magnetization of the first ferromagnetic layer. The first ferromagnetic layer, the first non-magnetic intermediate layer, and the second ferromagnetic layer are stacked in this order. A sense current flows through the stacked layers substantially in the direction of stacking.Type: GrantFiled: February 4, 2005Date of Patent: March 3, 2009Assignee: TDK CorporationInventors: Daisuke Miyauchi, Tomohito Mizuno
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Patent number: 7495868Abstract: A magnetic sensing element and exchange coupling film is disclosed. The magnetic sensing element has a free magnetic layer, nonmagnetic material layers disposed on the top and bottom of the free magnetic layer, pinned magnetic layers disposed on the top of one nonmagnetic material layer and on the bottom of the other nonmagnetic material layer, and antiferromagnetic layers containing IrMn disposed on the top of one pinned magnetic layer and on the bottom of the other pinned magnetic layer. The magnetization of the free magnetic layer is aligned in a direction orthogonal to the magnetization direction of the pinned magnetic layers. The exchange coupling film is formed by the antiferromagnetic layer and the pinned magnetic layer above the free magnetic layer. At least an interfacial portion of the ferromagnetic layer which is adjacent to the antiferromagnetic layer contains Co100-xFex wherein 30%?x?90% in atomic percent.Type: GrantFiled: July 12, 2005Date of Patent: February 24, 2009Assignee: Alps Electric Co., Ltd.Inventors: Takuya Seino, Fumihito Koike, Naoya Hasegawa
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Patent number: 7495867Abstract: A magnetoresistive read head includes a spin valve having at least one free layer spaced apart from at least one pinned layer by a spacer. The free layer includes a cobalt compound as a thin film including at least one of Co—X, CoFe—X and CoNi—X, where X is an element from the lanthanoid family (a 4-f element). The content of Co is higher than 80 percent, and the content of the lanthanoid element is less than 10 percent. The film may comprise the entire free layer, or be positioned adjacent to one or more conventional free layer films. The pinned layer is a conventional single layer, or a synthetic multi-layered structure having a spacer between sub-layers. Because the spin valve structure has a high exchange stiffness and damping factor, spin transfer effect is reduced and a high-speed dynamic response is provided.Type: GrantFiled: April 4, 2004Date of Patent: February 24, 2009Assignee: TDK CorporationInventors: Rachid Sbiaa, Isamu Sato
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Publication number: 20090046397Abstract: A synthetic antiferromagnet (SAF) structure includes a bottom ferromagnetic layer, a coupling layer formed over the bottom ferromagnetic layer, and a top ferromagnetic layer formed over the coupling layer. One of the top and bottom ferromagnetic layers comprises an amorphous alloy characterized by (Co100-aFea)100-zBz, where a is less than approximately 10 atomic percent, and z is greater than approximately 20 atomic percent. In general, a magnetic device includes at least one magnetic layer comprising an amorphous CoFeB alloy characterized by (Co100-aFea)100-zBz, where a is less than approximately 10 atomic percent, and z is greater than approximately 20 atomic percent.Type: ApplicationFiled: August 15, 2007Publication date: February 19, 2009Applicant: FREESCALE SEMICONDUCTOR, INC.Inventors: Jijun Sun, Renu W. Dave, Jon M. Slaughter
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Publication number: 20090034134Abstract: A magnetoresistance effect element includes a magnetoresistance effect film including a magnetically pinned layer having a magnetic material film whose direction of magnetization is pinned substantially in one direction, a magnetically free layer having a magnetic material film whose direction of magnetization changes in response to an external magnetic field, and a nonmagnetic metal intermediate layer located between said pinned layer and said free layer. The element also includes a pair of electrodes electrically connected to the magnetoresistance effect film to supply a sense current perpendicularly to a film plane of the magnetoresistance effect film. At least one of the pinned layer and the free layer may include a thin-film insertion layer.Type: ApplicationFiled: September 23, 2008Publication date: February 5, 2009Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Hiromi Yuasa, Yuzo Kamiguchi, Masatoshi Yoshikawa, Katsuhiko Koul, Hitoshi Iwasaki, Tomohiko Nagata, Takeo Sakakubo, Masashi Sahashi
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Patent number: 7486487Abstract: A magneto-resistive element employs a CPP structure and includes an antiferromagnetic layer, a pinned magnetization layer, a nonmagnetic intermediate layer and a free magnetization layer that are successively stacked. The pinned magnetization layer includes a first pinned magnetization layer, a nonmagnetic coupling layer and a second pinned magnetization layer that are successively stacked on the antiferromagnetic layer, and the first and second pinned magnetization layers are antiferromagnetically exchange-coupled. One of the first and second pinned magnetization layer is formed by a ferromagnetic layer made of a ferromagnetic material at least including one element or alloy selected from a group consisting of Co, Fe, Ni and alloys thereof, and the other is formed by a resistance control layer made of a conductive ferromagnetic oxide.Type: GrantFiled: May 25, 2005Date of Patent: February 3, 2009Assignee: Fujitsu LimitedInventors: Hirotaka Oshima, Reiko Kondo, Arata Jogo, Yutaka Shimizu, Atsushi Tanaka
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Publication number: 20090027812Abstract: The magnetic signal reproduction system comprises a magnetic recording medium comprising a magnetic layer comprising a ferromagnetic powder and a binder on a nonmagnetic support and a reproduction head, wherein a number of protrusions equal to or greater than 10 nm in height on the magnetic layer surface, as measured by an atomic force microscope, ranges from 50 to 2500/10,000 ?m2, a quantity of lubricant on the magnetic layer surface, denoted as a surface lubricant index, ranges from 0.5 to 5.0, a surface abrasive occupancy of the magnetic layer ranges from 2 to 20 percent, the reproduction head is a magnetoresistive magnetic head comprising a spin-valve layer, the spin-valve layer comprises a magnetization free layer, a magnetization pinned layer and an antiferromagnetic layer, and the antiferromagnetic layer is comprised of alloy comprising iridium and manganese, and the reproduction head comes in sliding contact with the magnetic recording medium during signal reproduction.Type: ApplicationFiled: July 28, 2008Publication date: January 29, 2009Applicants: FUJIFILM Corporation, TDK CorporationInventors: Hitoshi Noguchi, Yasushi Endo, Osamu Shimizu, Makoto Yoshida, Kazuhiko Maejima, Mitsuyoshi Kawai
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Patent number: 7483246Abstract: A magnetoresistive sensor having a novel seed layer that allows a bias layer formed there over to have exceptional hard magnetic properties when deposited over a crystalline structure such as an AFM layer of in a partial mill sensor design. The seed layer structure may be a CrMo/Si/CrMo sandwich or may also be a CrMo/Si/Cr sandwich and interrupts the epitaxial growth of an underlying crystalline structure, allowing a hard magnetic material formed over the seed layer to have a desired grain structure that is different from that of the underlying crystalline layer.Type: GrantFiled: September 29, 2004Date of Patent: January 27, 2009Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventor: Mustafa Michael Pinarbasi
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Patent number: 7483245Abstract: There is provided a practical magnetoresistance effect element which has an appropriate value of resistance, which can be sensitized and which has a small number of magnetic layers to be controlled, and a magnetic head and magnetic recording and/or reproducing system using the same. In a magnetoresistance effect element wherein a sense current is caused to flow in a direction perpendicular to the plane of the film, if a pinned layer and a free layer have a stacked construction of a magnetic layer and a non-magnetic layer or a stacked construction of a magnetic layer and a magnetic layer, it is possible to provide a practical magnetoresistance effect element which has an appropriate value of resistance, which can be sensitized and which has a small number of magnetic layers, while effectively utilizing the scattering effect depending on spin.Type: GrantFiled: March 4, 2008Date of Patent: January 27, 2009Assignee: Kabushiki Kaisha ToshibaInventors: Yuuzo Kamiguchi, Hiromi Yuasa, Tomohiko Nagata, Hiroaki Yoda
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Publication number: 20090021870Abstract: A magnetic head having a CPP read head sensor that includes a layered sensor stack including an antiferromagnetic (AFM) layer, a pinned magnetic layer, and a free magnetic layer. The pinned magnetic layer is comprised of a high, positive magnetostriction material and has a thickness t and a height (H), such that the ratio (t/H) of the thickness t to the height H of the pinned magnetic layer is fabricated to be within the range of from approximately 1/10 to approximately 1/500. Ion milling is conducted at a grazing angle to the surface of the layer upon which the pinned magnetic layer is fabricated, where the ion beam is oriented in the direction of the desired magnetization of the pinned magnetic layer.Type: ApplicationFiled: July 17, 2007Publication date: January 22, 2009Inventor: Mustafa Michael Pinarbasi
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Publication number: 20090015972Abstract: The present invention relates to a magnetoresistive sensor comprising a first pinned-magnetization magnetic layer (410) and a second free-magnetization magnetic layer (430), called sensitive layer, separated by first separating layer (420) for magnetic uncoupling. The sensor further comprises a second pinned-magnetization magnetic layer (450), separated from said sensitive layer by a second separating layer (440) for magnetic uncoupling, the first and second separating layers being located on either side of said sensitive layer, and the respective magnetizations of the first pinned-magnetization magnetic layer and of the sensitive layer, in the absence of an external field, being substantially orthogonal. The orientation of the magnetization of the second pinned layer is selected.Type: ApplicationFiled: May 19, 2008Publication date: January 15, 2009Applicant: COMMISSARIAT A L'ENERGIE ATOMIQUEInventors: Bernard Dieny, Claire Baraduc, Sebastien Petit, Christophe Thirion
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Patent number: 7477491Abstract: It has been found that the insertion of a copper laminate within CoFe, or a CoFe/NiFe composite, leads to higher values of CPP GMR and DRA. However, this type of structure exhibits very negative magnetostriction, in the range of high ?10?6 to ?10?5. This problem has been overcome by giving the copper laminates an oxygen exposure treatment When this is done, the free layer is found to have a very low positive magnetostriction constant. Additionally, the value of the magnetostriction constant can be adjusted by varying the thickness of the free layer and/or the position and number of the oxygen treated copper laminates.Type: GrantFiled: November 7, 2005Date of Patent: January 13, 2009Assignee: Headway Technologies, Inc.Inventors: Min Li, Kunliang Zhang, Masashi Sano, Koichi Terunuma, Simon Liao, Kochan Ju
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Patent number: 7475471Abstract: A GMR read head for a magnetic head, in which the hard bias layers are fabricated immediately next to the side edges of the free magnetic layer, and such that the midplane of the hard bias layer and the midplane of the free magnetic layer are approximately coplanar. The positioning of the hard bias layer is achieved by depositing a thick hard bias seedlayer, followed by an ion milling step is to remove seed layer sidewall deposits. Thereafter, the hard bias layer is deposited on top of the thick seed layer. Alternatively, a first portion of the hard bias seed layer is deposited, followed by an ion milling step to remove sidewall deposits. A thin second portion of the seed layer is next deposited, and the hard bias layer is then deposited.Type: GrantFiled: November 13, 2006Date of Patent: January 13, 2009Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventor: Mustafa Michael Pinarbasi
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Publication number: 20090009915Abstract: A method of generating a thin film for use in a spin valve of a magnetoresistive (MR) sensor having a nano-constricted spacer is provided. The bottom portion of the spin valve is deposited up to the pinned layer, a deposition chamber is provided, and the spacer layer is sputtered thereon. A main ion beam generates ions onto a composite surface including magnetic chips and insulator material. Simultaneously, an assisted ion beam provides ions directly to the substrate, thus improving the softness of the free layer and smoothness of the spacer layer. Neutralizers are also provided to prevent ion repulsion and improve ion beam focus. As a result, a thin film spacer can be formed, and the nano-constricted MR spin valve having low free layer coercivity and low interlayer coupling between the free layer and pinned layer is formed.Type: ApplicationFiled: July 24, 2008Publication date: January 8, 2009Inventors: Rachid Sbiaa, Isamu Sato, Haruyuki Morita
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Patent number: 7472469Abstract: A method is disclosed for fabricating a read sensor for a magnetic head for a hard disk drive having a read sensor stack and two lateral stacks. The method of fabrication includes forming lateral stacks on a gap layer, surrounding a groove to form a template. The read sensor stack is then formed in the groove, which defines the lateral dimensions of the read sensor stack, and lead layers are then formed on the lateral stacks. Also disclosed is a read head for a disk drive having a sensor stack defined by pre-established lateral stacks, and a disk drive having the read head.Type: GrantFiled: September 20, 2005Date of Patent: January 6, 2009Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: David Eugene Heim, Kim Y. Lee, Tsann Lin, Jih-Shiuan Luo, Chun-Ming Wang
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Patent number: 7471492Abstract: A magnetoresistive element has a first magnetic layer and a second magnetic layer separate from each other, the first magnetic layer and the second magnetic layer each having a magnetization whose direction is substantially pinned, and a non-magnetic conductive layer formed in contact with the first magnetic layer and the second magnetic layer and electrically connecting the first and second magnetic layers, the non-magnetic conductive layer forming a path of spin-polarized electrons from one of the magnetic layer to the other magnetic layer, the non-magnetic conductive layer comprising a portion located between the first magnetic layer and the second magnetic layer, the portion being a sensing area.Type: GrantFiled: July 22, 2004Date of Patent: December 30, 2008Assignee: Kabushiki Kaisha ToshibaInventors: Hideaki Fukuzawa, Hiromi Yuasa, Susumu Hashimoto, Hitoshi Iwasaki
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Publication number: 20080316657Abstract: An insertion layer is provided between an AFM layer and an AP2 pinned layer in a GMR or TMR element to improve exchange coupling properties by increasing Hex and the Hex/Hc ratio without degrading the MR ratio. The insertion layer may be a 1 to 15 Angstrom thick amorphous magnetic layer comprised of at least one element of Co, Fe, or Ni, and at least one element having an amorphous character selected from B, Zr, Hf, Nb, Ta, Si, or P, or a 1 to 5 Angstrom thick non-magnetic layer comprised of Cu, Ru, Mn, Hf, or Cr. Preferably, the content of the one or more amorphous elements in the amorphous magnetic layer is less than 40 atomic %. Optionally, the insertion layer may be formed within the AP2 pinned layer. Examples of an insertion layer are CoFeB, CoFeZr, CoFeNb, CoFeHf, CoFeNiZr, CoFeNiHf, and CoFeNiNbZr.Type: ApplicationFiled: June 19, 2007Publication date: December 25, 2008Inventors: Kunliang Zhang, Hui-Chuan Wang, Tong Zhao, Min Li
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Patent number: 7466524Abstract: In one illustrative example, a spin valve (SV) sensor of the self-pinned type includes a free layer; an antiparallel (AP) self-pinned layer structure; and a non-magnetic electrically conductive spacer layer in between the free layer and the AP self-pinned layer structure. The AP self-pinned layer structure includes a first AP pinned layer having a first thickness; a second AP pinned layer having a second thickness; and an antiparallel coupling (APC) layer formed between the first and the second AP pinned layers. The first thickness is slightly greater than the second thickness. Configured as such, the AP pinned layer structure provides for a net magnetic moment that is in the same direction as a magnetic field produced by the sense current flow, which reduces the likelihood of amplitude flip in the SV sensor.Type: GrantFiled: December 13, 2005Date of Patent: December 16, 2008Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: James Mac Freitag, Hardayal Singh Gill, Jih-Shiuan Luo, Mustafa Michael Pinarbasi
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Patent number: 7463458Abstract: A magnetic disk apparatus having a highly sensitive reproducing head and a method for manufacturing the magnetic disk apparatus are disclosed. A spin-valve-type multilayer film composed of an antiferromagnetic layer, a ferromagnetic layer, a nonmagnetic layer and a free magnetic layer is used as a magnetoresistive-effect device for the reproducing head. An antiferromagnetic reaction layer is formed between the antiferromagnetic layer and the ferromagnetic layer. The antiferromagnetic reaction layer is formed of a metallic compound containing oxygen.Type: GrantFiled: October 30, 2007Date of Patent: December 9, 2008Assignee: Panasonic CorporationInventor: Akifumi Aono
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Patent number: 7463457Abstract: A CPP giant magnetoresistive element includes a multilayer film including a lower pinned magnetic layer having a laminated ferrimagnetic structure including a lower first pinned magnetic sublayer, a lower nonmagnetic intermediate sublayer, and a lower second pinned magnetic sublayer; a lower nonmagnetic layer; a free magnetic layer; an upper nonmagnetic layer; and an upper pinned magnetic layer having a laminated ferrimagnetic structure including an upper second pinned magnetic sublayer, an upper nonmagnetic intermediate sublayer, and an upper first pinned magnetic sublayer disposed in that order. Each of the free magnetic layer and the lower and upper second pinned magnetic sublayers is composed of a NiFeX alloy or NiFeCoX alloy, X being an element which decreases the saturation magnetization of a NiFe or NiFeCo base.Type: GrantFiled: May 8, 2007Date of Patent: December 9, 2008Assignee: TDK CorporationInventors: Naoya Hasegawa, Masamichi Saito
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Patent number: 7463456Abstract: A spin valve type magnetoresistive effect element for vertical electric conduction includes a magnetoresistive effect film in which a resistance adjustment layer made of a material containing conductive carriers not more than 1022/cm3 is inserted. Thus the resistance value of a portion in change of spin-relied conduction is raised to an adequate valve, thereby to increase the resistance variable amount.Type: GrantFiled: April 9, 2007Date of Patent: December 9, 2008Assignee: Kabushiki Kaisha ToshibaInventors: Hiromi Yuasa, Masatoshi Yoshikawa, Katsuhiko Koui, Hitoshi Iwasaki, Masashi Sahashi
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Publication number: 20080297954Abstract: A magnetic sensor includes a plurality of giant magnetoresistive elements, each of which includes a free layer, a conductive layer, and a pin layer sequentially laminated on a substrate, wherein the pin layer formed by sequentially laminating a first magnetic layer, an Ru layer, a second magnetic layer, and an antiferromagnetic layer is subjected to magnetization heat treatment so as to fix the magnetization direction thereof. The first and second magnetic layers differ from each other in thickness and magnetic moment thereof, and the thickness of the Ru layer ranges from 4 ? to 10 ?. The magnetization heat treatment is performed so as to maintain an anti-parallel state between the first and second magnetic layers. In order to detect magnetic fields in three-axial directions, one giant magnetoresistive element is formed using a planar surface, and the other giant magnetoresistive elements are formed using respective slopes on the substrate.Type: ApplicationFiled: April 18, 2008Publication date: December 4, 2008Applicant: YAMAHA CORPORATIONInventor: Kokichi Aiso
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Publication number: 20080291586Abstract: A tunneling magnetic sensor includes a platinum layer between a pinned magnetic layer and an insulating barrier layer. The platinum layer can probably vary the barrier height (potential height) and barrier width (potential width) of the insulating barrier layer to reduce the absolute value of VCR, thus providing higher operating stability than known tunneling magnetic sensors. In addition, the insulating barrier layer can achieve increased flatness at its bottom interface (where the insulating barrier layer starts to be formed). The tunneling magnetic sensor can therefore provide a higher rate of resistance change (?R/R) at low RA than known tunneling magnetic sensors.Type: ApplicationFiled: August 3, 2007Publication date: November 27, 2008Inventors: Masahiko Ishizone, Naoya Hasegawa, Masamichi Saito, Yosuke Ide, Ryo Nakabayashi, Kazumasa Nishimura
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Publication number: 20080291585Abstract: It is made possible to provide a magnetoresistive effect element that can reverse magnetization direction with a low current, having low areal resistance (RA) and a high TMR ratio. A magnetoresistive effect element includes: a film stack that includes a magnetization free layer including a magnetic layer in which magnetization direction is changeable, a magnetization pinned layer including a magnetic layer in which magnetization direction is pinned, and an intermediate layer provided between the magnetization free layer and the magnetization pinned layer, the intermediate layer being an oxide containing boron (B) and an element selected from the group consisting of Ca, Mg, Sr, Ba, Ti, and Sc. Current is applied bidirectionally between the magnetization pinned layer and the magnetization free layer through the intermediate layer, so that the magnetization of the magnetization free layer is reversible.Type: ApplicationFiled: August 23, 2007Publication date: November 27, 2008Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Masatoshi Yoshikawa, Tadashi Kai, Toshihiko Nagase, Eiji Kitagawa, Tatsuya Kishi, Hiroaki Yoda
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Publication number: 20080285181Abstract: A method for providing a giant magneto-resistive (GMR) sensor for use in sensing magnetic flux is provided. The method comprises positioning a layer of Cu material between first and second layers of a specified ferromagnetic material. The respective end surfaces of the Cu layer and the first and second layers are initially located in a common plane and in a co-planar relationship with one another. The method further comprises removing an amount of material from the copper layer to form a new end surface thereof that is selectively spaced apart from the common plane and applying a protective coating to the new end surface of the Cu layer to inhibit corrosion of the Cu layer.Type: ApplicationFiled: June 5, 2008Publication date: November 20, 2008Applicant: STORAGE TECHNOLOGY CORPORATIONInventors: John P. Nibarger, Herbert House
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Publication number: 20080285182Abstract: An anti-parallel pinned sensor is provided with a spacer that increases the anti-parallel coupling strength of the sensor. The anti-parallel pinned sensor is a GMR or TMR sensor having a pure ruthenium or ruthenium alloy spacer. The thickness of the spacer is less than 0.8 nm, preferably between 0.1 and 0.6 nm. The spacer is also annealed in a magnetic field that is 1.5 Tesla or higher, and preferably greater than 5 Tesla. This design yields unexpected results by more than tripling the pinning field over that of typical AP-pinned GMR and TMR sensors that utilize ruthenium spacers which are 0.8 nm thick and annealed in a relatively low magnetic field of approximately 1.3 Tesla.Type: ApplicationFiled: July 11, 2008Publication date: November 20, 2008Inventors: Wen-Yaung Lee, Jinshan Li, Daniele Mauri, Koichi Nishioka, Yasunari Tajima
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Publication number: 20080285183Abstract: An area of an element can be made small and fluctuation in area can be reduced. A magneto-resistance effect element is provided with a first electrode with an end face; a magneto-resistance effect film which is formed such that a surface thereof comes in contact with the end face of the first electrode; and a second electrode which is formed on another surface of the magneto-resistance effect element opposed from the surface coming in contact with the surface of the first electrode. The magneto-resistance effect film includes a magnetization pinned layer whose magnetization direction is pinned, a magnetization free layer whose magnetization direction is changeable, and a first non-magnetic layer which is provided between the magnetization pinned layer and the magnetization free layer.Type: ApplicationFiled: July 22, 2008Publication date: November 20, 2008Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Hideyuki Sugiyama, Yoshiaki Saito
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Publication number: 20080278863Abstract: A tunneling magnetic sensing element includes: a pinned magnetic layer whose direction of magnetization is pinned in one direction; an insulating barrier layer; and a free magnetic layer whose direction of magnetization changes in response to an external magnetic field. The pinned magnetic layer, the insulating barrier layer and the free magnetic layer are deposited in the named order. A first protective layer composed of a platinum-group element is disposed on the free magnetic layer, and a second protective layer composed of Ti is disposed on the first protective layer.Type: ApplicationFiled: May 9, 2008Publication date: November 13, 2008Inventors: Kazumasa Nishimura, Masamichi Saito, Yoshihiro Nishiyama, Hidekazu Kobayashi, Naoya Hasegawa
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Patent number: 7450350Abstract: A current-perpendicular-to-the-plane spin-valve (CPP-SV) magnetoresistive sensor has an improved antiparallel (AP) pinned structure, i.e., a structure with first (AP1) and second (AP2) ferromagnetic layers separated by a nonmagnetic antiparallel coupling (APC) layer with the magnetization directions of AP1 and AP2 oriented substantially antiparallel. The AP2 ferromagnetic layer (the layer in contact with the SV spacer layer) is an alloy of a ferromagnetic material and one or more additive elements of Cu, Au and Ag. The additive elements reduce the magnetic moment of the AP2 layer, which enables its thickness to be increased so that its magnetic moment remains close to the magnetic moment of the AP1 ferromagnetic layer. The thicker AP2 layer allows for more bulk spin-dependent scattering of electrons which increases the magnetoresistance of the sensor.Type: GrantFiled: August 30, 2005Date of Patent: November 11, 2008Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Matthew J. Carey, Jeffrey R. Childress, Stefan Maat
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Publication number: 20080273279Abstract: A magnetoresistive assembly includes at least a first and a second magnetoresistive element formed on a common substrate, the at least first magnetoresistive element comprising a first pinned ferromagnetic layer being magnetized in a first direction, the at least second magnetoresistive element comprising a second pinned ferromagnetic layer being magnetized in a second direction different than the first direction.Type: ApplicationFiled: July 16, 2008Publication date: November 6, 2008Inventors: Johannes Paul, Rolf Schaefer
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Patent number: 7446983Abstract: An MR element comprises: a nonmagnetic conductive layer having two surfaces facing toward opposite directions; a free layer disposed adjacent to one of the surfaces of the nonmagnetic conductive layer, wherein the direction of magnetization in the free layer changes in response to an external magnetic field; and a pinned layer disposed adjacent to the other of the surfaces of the nonmagnetic conductive layer, wherein the direction of magnetization in the pinned layer is fixed. The pinned layer incorporates a first pinned layer, a coupling layer and a second pinned layer. The second pinned layer incorporates first to third magnetic layers each of which is made of a magnetic material. Layered structures each made up of a Cu film, a magnetic film and a Cu film are inserted between the first magnetic layer and the second magnetic layer, and between the second magnetic layer and the third magnetic layer, respectively.Type: GrantFiled: December 3, 2004Date of Patent: November 4, 2008Assignee: TDK CorporationInventors: Daisuke Miyauchi, Tomohito Mizuno
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Patent number: 7446984Abstract: A Magnetic Random Access Memory (MRAM) cell and array for storing data. The MRAM array includes a memory cell having a magnetic pinned layer, a magnetic free layer and a non-magnetic spacer or barrier layer sandwiched between the pinned and free layer. The pinned layer has magnetization that is pinned, and the free layer has a magnetization that is free to rotate but is stable in directions that are parallel or antiparallel with the magnetization of the pinned layer. The free layer has a magnetic anisotropy the maintains the stability of the free layer magnetization. The free layer anisotropy is induced by a surface roughness either in the surface of the free layer itself, or in the surface of the underling barrier/spacer layer. This anisotropic roughness is induced by an angled direct ion milling.Type: GrantFiled: October 2, 2006Date of Patent: November 4, 2008Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Matthew Joseph Carey, Jeffrey Robinson Childress, Stefan Maat
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Patent number: 7446986Abstract: A magnetoresistive sensor having an in stack bias structure. The sensor includes a bias spacer that allows biasing of free layer magnetic moment in a direction orthogonal to the magnetic moment of the biasing layer.Type: GrantFiled: August 31, 2004Date of Patent: November 4, 2008Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Satoru Araki, Jeffrey Robinson Childress, Stefan Maat, Daniele Mauri, Matthew Joseph Carey
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Patent number: 7446982Abstract: A magnetoresistive sensor having a trilayer structure for improved pinning. The pinned layer is exchange coupled with a IrMnCr AFM layer, and has a three ferromagnetic layer, the center one comprising Co50Fe50 and V.Type: GrantFiled: July 1, 2004Date of Patent: November 4, 2008Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventor: Hardayal Singh Gill
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Publication number: 20080266725Abstract: A tunnel junction TMR magnetoresistive sensor formed on layers having nitrogen interspersed therein. The nitrogenation of the layers on which the sensor is deposited allows the sensor layers to have very smooth, uniform surfaces. This greatly improves sensor performance by, for example, providing a very uniform barrier layer thickness.Type: ApplicationFiled: May 23, 2008Publication date: October 30, 2008Inventors: Thomas E. Shatz, Dulip Ajantha Welipitiya, Brian R. York
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Patent number: 7443638Abstract: Disclosed herein is a magnetoresistive structure, for example useful as a spin-valve or GMR stack in a magnetic sensor, and a fabrication method thereof. The magnetoresistive structure uses twisted coupling to induce a perpendicular magnetization alignment between the free layer and the pinned layer. Ferromagnetic layers of the free and pinned layers are exchange-coupled using antiferromagnetic layers having substantially parallel exchange-biasing directions. Thus, embodiments can be realized that have antiferromagnetic layers formed of a same material and/or having a same blocking temperature. At least one of the free and pinned layers further includes a second ferromagnetic layer and an insulating layer, such as a NOL, between the two ferromagnetic layers. The insulating layer causes twisted coupling between the two ferromagnetic layers, rotating the magnetization direction of one 90 degrees relative to the magnetization direction of the other.Type: GrantFiled: April 22, 2005Date of Patent: October 28, 2008Assignee: Taiwan Semiconductor Manufacturing Company Ltd.Inventors: Yu-Jen Wang, Chih-Huang Lai, Wen-Chin Lin, Denny Tang, Chao-Hsiung Wang
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Patent number: 7441326Abstract: In a magnetic sensor, a lower terminal layer, a magnetosensitive layer, and a cover film are simultaneously patterned into substantially the same size. The opposing surface of the lower terminal layer, which opposes the magnetosensitive film is substantially superposed on one opposing surface of the magnetosensitive film. The opposing surface of the upper terminal layer, which opposes the magnetosensitive film is formed into a shape smaller than and included in the other opposing surface of the magnetosensitive film. This implements a magnetic sensor which uses a CPP structure and is yet readily processible and which includes a substantially accurate fine CPP structure in accordance with a desired output.Type: GrantFiled: August 17, 2006Date of Patent: October 28, 2008Assignee: Fujitsu LimitedInventors: Yoshihiko Seyama, Atsushi Tanaka
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Patent number: 7443637Abstract: A giant magnetoresistance (GMR) sensor with side longitudinal bias (LB) stacks is proposed for magnetic recording at ultrahigh densities. The GMR sensor extends from a read region into two side regions. The side LB stacks overlies the GMR sensor in the two side regions, rigidly pinning sense layers through antiparallel coupling across an antiparallel coupling spacer layer. Magnetostatic interactions occur in the sense layers between the read and side regions, thereby stabilizing the sense layers in the read region.Type: GrantFiled: July 11, 2005Date of Patent: October 28, 2008Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventor: Tsann Lin
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Patent number: 7440239Abstract: It is possible to obtain sensitivity which can achieve an excellent error rate with a high recording density. There are provided a magnetization free layer which has two opposed main surfaces, one of which is set to be generally parallel to an air bearing surface; an intermediate layer which is formed on an opposite side face of the magnetization free layer from a medium to come in contact with the magnetization free layer; and a pair of magnetization pinned layers which are formed on an opposite side face of the intermediate layer from the magnetization free layer to come in contact with the intermediate layer and extend outwardly. A sense current flows from one magnetization pinned layer to the other magnetization pinned layer through the magnetization free layer.Type: GrantFiled: September 29, 2003Date of Patent: October 21, 2008Assignee: Kabushiki Kaisha ToshibaInventors: Yuzo Kamiguchi, Masayuki Takagishi, Yuichi Ohsawa
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Patent number: 7436637Abstract: A magnetoresistive sensor having a hard magnetic layer extending from the stripe height of the pinned layer to assist in pinning the pinned layer. The pinned layer extends beyond the stripe height of the free layer so that the back stripe height edge of the pinned layer is significantly beyond the stripe height edge of the free layer. The pinned layer is preferably constructed to have a net magnetic moment such that magnetostatic coupling between the hard magnetic layer and the pinned layer pins the moment of the layers. The hard magnetic layer can be used in addition to or in lieu of an AFM pinning layer.Type: GrantFiled: October 5, 2005Date of Patent: October 14, 2008Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventor: Mustafa Michael Pinarbasi
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Patent number: 7436638Abstract: A CPP magnetic sensor is disclosed with a ferromagnetic layer that extends in a first direction a first distance; a nonferromagnetic spacer layer that adjoins the ferromagnetic layer and extends in the first direction a second distance that is substantially equal to the first distance; and a ferromagnetic structure that is separated from the ferromagnetic layer by the spacer layer, the ferromagnetic structure having a first section that extends in the first direction a third distance that is substantially equal to the second distance, the ferromagnetic structure having a second section that is disposed further than the first section from the spacer layer, the second section extending at least twice as far as the first section in the first direction. The ferromagnetic structure can be used for in-stack bias or pinning of free or pinned layers, respectively, and side shields can be provided for high areal density.Type: GrantFiled: September 18, 2007Date of Patent: October 14, 2008Assignee: Western Digital (Fremont), LLCInventor: Tao Pan
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Publication number: 20080247097Abstract: A magnetoresistance effect element has a lamination structure comprising a free layer including two ferromagnetic layers, a pinned layer including two ferromagnetic layers, and at least one nano-contact portion composed of a single ferromagnetic layer and disposed at least one portion between the free layer and the pinned layer. A distance between the free layer and the pinned layer, i.e., thickness of the nano-contact portion in the lamination direction, is not more than Fermi length, preferably less than 100 nm.Type: ApplicationFiled: February 27, 2007Publication date: October 9, 2008Applicant: TDK CORPORATIONInventors: Isamu SATO, Rachid SBIAA
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Patent number: 7433161Abstract: A nonmagnetic material-noncontact layer forming a fixed magnetic layer is formed using CoFe, a nonmagnetic material-contact layer is formed using Co, and an NOL (Nano-Oxide Layer) is provided between the nonmagnetic material-noncontact layer and the nonmagnetic material-contact layer. In addition, the average film thickness of the nonmagnetic material-contact layer is set in the range of 16 to 19 ?. Accordingly, compared to a three-layered structure composed of CoFe, an NOL, and CoFe or a three-layered structure composed of Co, an NOL, and Co, which has been conventionally used, the rate (?R/R) of change in resistance and the unidirectional exchange bias magnetic field (Hex*) can both be improved.Type: GrantFiled: January 12, 2005Date of Patent: October 7, 2008Assignee: Alps Electric Co., Ltd.Inventors: Kazuaki Ikarashi, Naoya Hasegawa, Fumihito Koike, Eiji Umetsu
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Patent number: 7433162Abstract: An antiferromagnetically exchange-coupled structure for use in a magnetic device, such as a magnetoresistive sensor, includes an enhancement layer formed of a chemically-ordered tetragonal-crystalline alloy, a chemically-ordered tetragonal-crystalline Mn-alloy antiferromagnetic layer in contact with the enhancement layer, and a ferromagnetic layer exchange-coupled with the antiferromagnetic layer. The enhancement layer is an alloy selected from the group consisting of alloys of AuCu, FePt, FePd, AgTi3, Pt Zn, PdZn, IrV, CoPt and PdCd, and the antiferromagnetic layer is an alloy of Mn with Pt, Ni, Ir, Pd or Rh. The enhancement layer enhances the transformation of the Mn alloy from the chemically-disordered phase to the chemically-ordered phase.Type: GrantFiled: February 16, 2006Date of Patent: October 7, 2008Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Matthew J. Carey, Brian R. York
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Publication number: 20080232003Abstract: An underlying layer (2) made of NiFeN is disposed over the principal surface of a substrate. A pinning layer (3) made of antiferromagnetic material containing Ir and Mn is disposed on the underlying layer. A reference layer (4c) made of ferromagnetic material whose magnetization direction is fixed through exchange-coupling with the pinning layer directly or via another ferromagnetic material layer, is disposed over the pinning layer. A nonmagnetic layer (7) made of nonmagnetic material is disposed over the reference layer. A free layer (8) made of ferromagnetic material whose magnetization direction changes in dependence upon an external magnetic field, is disposed over the nonmagnetic layer.Type: ApplicationFiled: March 3, 2008Publication date: September 25, 2008Applicant: FUJITSU LIMITEDInventors: Takahiro IBUSUKI, Masashige SATO, Shinjiro UMEHARA
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Patent number: 7428128Abstract: A magnetic sensing element has pinned magnetic layers disposed on the two sides of a free magnetic layer in the track width direction with nonmagnetic conductive layers therebetween, and an electric current flows through these layers in parallel to the surfaces. The back end of the free magnetic layer in the track width direction extends in parallel to the track width direction. The back ends of the nonmagnetic conductive layers are coincident with the reference line drawn by extending the back end of the free magnetic layer. At least part of the back ends of the pinned magnetic layers is coincident with the reference line. Each pinned magnetic layer is shaped so that the region near the nonmagnetic conductive layer and the free magnetic layer has a smaller length in the height direction to achieve higher current density.Type: GrantFiled: January 12, 2004Date of Patent: September 23, 2008Assignee: TDK CorporationInventors: Naoya Hasegawa, Masamichi Saito
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Patent number: 7428127Abstract: A CPP magnetoresistive effect element includes a free magnetization layer, a fixed magnetization layer, and a plurality of conductive non-magnetic intermediate layers formed between the free magnetization layer and the fixed magnetization layer. An insulating layer and a magnetic layer including magnetic atoms are provided between any two of the non-magnetic intermediate layers.Type: GrantFiled: January 25, 2005Date of Patent: September 23, 2008Assignee: Fujitsu LimitedInventors: Keiichi Nagasaka, Yoshihiko Seyama, Hirotaka Oshima, Yutaka Shimizu, Atsushi Tanaka
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Patent number: 7426097Abstract: An enhanced giant magnetoresistive device, and a method of manufacturing the same. The enhanced giant magnetoresistive (GMR) device includes a substrate over which is formed a seed layer. A buffer-oxide layer is formed over the seed layer. Formed over the buffer-oxide layer is a GMR stack. The GMR stack is formed as a three layer sandwich in which the two outside layers are fabricated from ferromagnetic materials, and the inner layer or spacer layer is formed from non-magnetic, conducting materials. The GMR stack may also take the form of spin valves, and/or other GMR stacks. The buffer-oxide layer may be various thicknesses and provide desirable texturing or non-waviness, both of which may allow for a thin spacer layer. Further, the buffer-oxide layer may be configured to prevent Néel-type-orange-peel coupling from dominating RKKY coupling in the GMR device, which may allow for a thin spacer layer.Type: GrantFiled: July 19, 2002Date of Patent: September 16, 2008Assignee: Honeywell International, Inc.Inventors: Joel Drewes, William Witcraft
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Publication number: 20080218914Abstract: A read sensor with a uniform longitudinal bias (LB) stack is proposed. The read sensor is a giant magnetoresistance (GMR) sensor used in a current-in-plane (CIP) or a current-perpendicular-to-plane (CPP) mode, or a tunneling magnetoresistance (TMR) sensor used in the CPP mode. The transverse pinning layer of the read sensor is made of an antiferromagnetic Pt—Mn, Ir—Mn or Ir—Mn—Cr film. In one embodiment of this invention, the uniform LB stack comprises a longitudinal pinning layer, preferable made of an antiferromagnetic Ir—Mn—Cr or Ir—Mn film, in direct contact with and exchange-coupled to sense layers of the read sensor. In another embodiment of the present invention, the uniform LB stack comprises the Ir—Mn—Cr or Ir—Mn longitudinal pinning layer exchange coupled to a ferromagnetic longitudinal pinned layer, and a nonmagnetic antiparallel-coupling spacer layer sandwiched between and the ferromagnetic longitudinal pinned layer and the sense layers.Type: ApplicationFiled: May 28, 2008Publication date: September 11, 2008Inventor: Tsann Lin
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Patent number: 7423848Abstract: A CPP-GMR spin value sensor structure with an improved MR ratio and increased resistance is disclosed. All layers except certain pinned layers, copper spacers, and a Ta capping layer are oxygen doped by adding a partial O2 pressure to the Ar sputtering gas during deposition. Oxygen doped CoFe free and pinned layers are made slightly thicker to offset a small decrease in magnetic moment caused by the oxygen dopant. Incorporating oxygen in the MnPt AFM layer enhances the exchange bias strength. An insertion layer such as a nano-oxide layer is included in one or more of the free, pinned, and spacer layers to increase interfacial scattering. The thickness of all layers except the copper spacer may be increased to enhance bulk scattering. A CPP-GMR single or dual spin valve of the present invention has up to a threefold increase in resistance and a 2 to 3% increase in MR ratio.Type: GrantFiled: July 27, 2007Date of Patent: September 9, 2008Assignee: Headway Technologies, Inc.Inventors: Cheng T. Horng, Ru-Ying Tong