Having Tunnel Junction Effect Patents (Class 360/324.2)
-
Patent number: 8068317Abstract: A magnetic tunnel transistor (MTT) having a pinned layer that has no antiferromagnetic material in an active area of the sensor. The MTT can include a layer of antiferromagnetic material that is exchange coupled with the pinned layer in an area outside of the active area of me sensor, such as outside the track-width, beyond the stripe height, or both outside the track-width and beyond the stripe height. The pinned layer can also be pinned without any exchange coupling at all. In that case, pinning can be assisted by shape enhanced magnetic anisotropy, by extending the pinned layer beyond the stripe height.Type: GrantFiled: April 9, 2008Date of Patent: November 29, 2011Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventor: Hardayal Singh Gill
-
Patent number: 8059372Abstract: Biasing schemes used for CIP GMR devices were previously thought to be impractical for CPP devices due to current shunting by the abutted hard magnets. In the present invention the CPP stripe is a narrow conductor directly above the free layer. The resistivity of the latter is made to be relatively high so the sensing current diverges very little as it passes through it. This makes it possible to use abutted hard magnets for longitudinal bias with virtually no loss of sensing current due to shunting by the magnets.Type: GrantFiled: July 24, 2007Date of Patent: November 15, 2011Assignee: Headway Technologies, Inc.Inventors: Yimin Guo, Li-Yan Zhu
-
Patent number: 8059374Abstract: 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: January 14, 2009Date of Patent: November 15, 2011Assignee: Headway Technologies, Inc.Inventors: Tong Zhao, Hui-Chuan Wang, Min Li, Kunliang Zhang
-
Patent number: 8058697Abstract: We describe a CPP MTJ MRAM element that utilizes transfer of spin angular momentum as a mechanism for changing the magnetic moment direction of a free layer. The device includes a tunneling barrier layer of MgO and a non-magnetic CPP layer of Cu or Cr and utilizes a novel synthetic free layer having three ferromagnetic layers mutually exchange coupled in pairwise configurations. The free layer comprises an inner ferromagnetic and two outer ferromagnetic layers, with the inner layer being ferromagnetically exchange coupled to one outer layer and anti-ferromagnetically exchange coupled to the other outer layer. The ferromagnetic coupling is very strong across an ultra-thin layer of Ta, Hf or Zr of thickness preferably less than 0.4 nm.Type: GrantFiled: March 26, 2007Date of Patent: November 15, 2011Assignee: MagIC Technologies, Inc.Inventors: Yimin Guo, Cheng Horng, Ru-Ying Tong
-
Patent number: 8054588Abstract: A tunnel magnetoresistive element includes a laminate including a pinned magnetic layer, an insulating barrier layer, and a free magnetic layer. The insulating barrier layer is composed of Ti—Mg—O or Ti—O. The free magnetic layer includes an enhancement sublayer, a first soft magnetic sublayer, a nonmagnetic metal sublayer, and a second soft magnetic sublayer. For example, the enhancement sublayer is composed of Co—Fe, the first soft magnetic sublayer and the second soft magnetic sublayer are composed of Ni—Fe, and the nonmagnetic metal sublayer is composed of Ta. The total thickness of the average thickness of the enhancement sublayer and the average thickness of the first soft magnetic sublayer is in the range of 25 to 80 angstroms. Accordingly, the tunneling magnetoresistive element can consistently have a higher rate of resistance change than before.Type: GrantFiled: February 11, 2011Date of Patent: November 8, 2011Assignee: Alps Electric Co., Ltd.Inventors: Kazumasa Nishimura, Ryo Nakabayashi, Yosuke Ide, Hasahiko Ishizone, Masamichi Saito, Naoya Hasegawa, Yoshihiro Nishiyana, Akio Hanada, Hidekezu Kobayashi
-
Patent number: 8045300Abstract: A free magnetic layer has a laminated structure in which a first magnetic sublayer composed of Co—Fe or Fe and a second magnetic sublayer composed of Co—Fe—B or Fe—B are formed, in that order, on an insulating barrier layer composed of Mg—O. This effectively improves the rate of change in resistance (?R/R) compared with the related art.Type: GrantFiled: February 25, 2008Date of Patent: October 25, 2011Assignee: TDK CorporationInventors: Kazumasa Nishimura, Yosuke Ide, Naoya Hasegawa, Masamichi Saito, Yoshihiro Nishiyama, Ryo Nakabayashi, Hidekazu Kobayashi
-
Patent number: 8043869Abstract: A magnetic memory device includes a common line; a first write-in diode, a readout diode and a second write-in diode being connected to the common line in parallel. The magnetic memory device further includes a magnetic tunnel junction structure connected to the readout diode, first and second write-in conductors disposed at both sides of the magnetic tunnel junction structure and connected to the first and second write-in diodes, respectively and a first write-in line, a readout line and a second write-in line, which are connected to the first write-in conductor, the magnetic tunnel injection structure, and the second write-in conductor, respectively.Type: GrantFiled: October 29, 2010Date of Patent: October 25, 2011Assignee: Samsung Electronics Co., Ltd.Inventors: Woo-Yeong Cho, Yun-Seung Shin, Hyun-Geun Byun, Choong-Keun Kwak
-
Patent number: 8045299Abstract: A method and apparatus for oxidizing conductive redeposition in TMR sensors is disclosed. A TMR stack having a first electrode that includes at least a pinned layer and an antiferromagnetic (AFM) layer, a second electrode that includes a free layer and a tunnel barrier is formed. The TMR barrier layer is etched. Redeposition material is oxidized and the barrier is healed using an oxidizing agent selected from the group consisting of ozone and water vapor.Type: GrantFiled: November 10, 2006Date of Patent: October 25, 2011Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Robert E. Fontana, Jr., Howard G. Zolla
-
Patent number: 8036024Abstract: In a ferromagnetic tunnel junction element, a recording layer is in a circular shape, which can suppress an increase in magnetization switching field due to miniaturization of the element. Further, the recording layer includes a first ferromagnetic layer, a first non-magnetic layer, a second ferromagnetic layer, a second non-magnetic layer, and a third ferromagnetic layer successively stacked. The first and second ferromagnetic layers, and the second and third ferromagnetic layers are coupled antiparallel to each other, so that it is possible to control the magnetization distribution of the recording layer in an approximately single direction.Type: GrantFiled: May 30, 2006Date of Patent: October 11, 2011Assignee: Renesas Electronics CorporationInventors: Takashi Takenaga, Takeharu Kuroiwa, Hiroshi Kobayashi, Sadeh Beysen
-
Patent number: 8035177Abstract: A magnetic stack having a ferromagnetic free layer, a metal oxide layer that is antiferromagnetic at a first temperature and non-magnetic at a second temperature higher than the first temperature, a ferromagnetic pinned reference layer, and a non-magnetic spacer layer between the free layer and the reference layer. During a writing process, the metal oxide layer is non-magnetic. For magnetic memory cells, such as magnetic tunnel junction cells, the metal oxide layer provides reduced switching currents.Type: GrantFiled: April 17, 2009Date of Patent: October 11, 2011Assignee: Seagate Technology LLCInventors: Xiaohua Lou, Yuankai Zheng, Wenzhong Zhu, Wei Tian, Zheng Gao
-
Patent number: 8035932Abstract: A Lorentz magnetoresistive sensor having integrated signal amplification. The sensor is constructed upon a substrate such as a semiconductor material, and an amplification circuit such as transistor is constructed directly into the substrate on which the magnetoresistive device is constructed. This integrated signal amplification greatly enhances sensor performance by eliminating a great deal of signal noise that would otherwise be added to the read signal.Type: GrantFiled: September 20, 2007Date of Patent: October 11, 2011Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Bruce Alvin Gurney, Ernesto E. Marinero, Andrew Stuart Troup, David Arfon Williams, Joerg Wunderlich
-
Patent number: 8035928Abstract: An apparatus includes a current perpendicular to the plane sensing element, a DC current source connected to the sensing element, a microwave AC current source connected to supply AC current to the sensing element, and a detector for measuring a voltage representative of phase difference between the AC current and AC voltage across the multilayer structure when the sensing element is subjected to a magnetic field. A method for sensing a magnetic field is also provided.Type: GrantFiled: January 9, 2009Date of Patent: October 11, 2011Assignee: Seagate Technology LLCInventor: Shehzaad Kaka
-
Patent number: 8035931Abstract: The conventional free layer in a TMR read head has been replaced by a composite of two or more magnetic layers, one of which is iron rich The result is an improved device that has a higher MR ratio than prior art devices, while still maintaining free layer softness and acceptable magnetostriction. A process for manufacturing the device is also described.Type: GrantFiled: May 28, 2010Date of Patent: October 11, 2011Assignee: Headway Technologies, Inc.Inventors: Tong Zhao, Hui-Chuan Wang, Chyu-Jiuh Torng
-
Publication number: 20110235217Abstract: Methods for forming a magnetic tunnel junction (MTJ) storage element and MTJ storage elements formed are disclosed. The MTJ storage element includes a MTJ stack having a pinned layer stack, a barrier layer and a free layer. An adjusting layer is formed on the free layer, such that the free layer is protected from process related damages. A top electrode is formed on the adjusting layer and the adjusting layer and the free layer are etched utilizing the top electrode as a mask. A spacer layer is then formed, encapsulating the top electrode, the adjusting layer and the free layer. The spacer layer and the remaining portions of the MTJ stack are etched. A protective covering layer is deposited over the spacer layer and the MTJ stack.Type: ApplicationFiled: March 29, 2010Publication date: September 29, 2011Applicant: QUALCOMM IncorporatedInventors: Wei-Chuan Chen, Seung H. Kang
-
Patent number: 8026563Abstract: A spin transistor comprises a spin injector for injecting, from a first nonmagnetic electrode carriers with a spin parallel to a spin band forming the band edge of a first ferromagnetic barrier layer, to a second nonmagnetic electrode layer, as hot carriers. It also comprises a spin analyzer whereby, due to spin-splitting at the band edge of a second ferromagnetic barrier layer, the spin-polarized hot carriers are transported to a third nonmagnetic electrode when the direction of the spin of the carriers injected into the second nonmagnetic electrode is parallel to that of the spin of the spin band at the band edge of the second ferromagnetic barrier layer, whereas the hot carriers are not transported to the third nonmagnetic electrode in the case of antiparallel spin. A memory element is also provided that comprises such a spin transistor.Type: GrantFiled: September 22, 2010Date of Patent: September 27, 2011Assignee: Japan Science and Technology AgencyInventors: Satoshi Sugahara, Masaaki Tanaka
-
Patent number: 8023233Abstract: A tunneling magnetic sensing element includes a pinned magnetic layer whose magnetization direction is pinned in one direction, an insulating barrier layer disposed on the pinned magnetic layer, a free magnetic layer whose magnetization direction varies in response to an external magnetic field disposed on the insulating barrier layer, and a first protective layer composed of iridium-manganese (IrMn) disposed on the free magnetic layer. Consequently, a high rate of change in resistance is obtained and the magnetostriction of the free magnetic layer is low, compared with a tunneling magnetic sensing element which is not provided with a first protective layer.Type: GrantFiled: November 27, 2007Date of Patent: September 20, 2011Assignee: TDK CorporationInventors: Kazumasa Nishimura, Ryo Nakabayashi, Naoya Hasegawa, Masamichi Saito, Yosuke Ide, Masahiko Ishizone
-
Patent number: 8018690Abstract: A CPP MTJ or GMR read sensor is provided in which the free layer is self-stabilized by a magnetization in a circumferential vortex configuration. This magnetization permits the pinned layer to be magnetized in a direction parallel to the ABS plane, which thereby makes the pinned layer directionally more stable as well. The lack of lateral horizontal bias layers or in-stack biasing allows the formation of closely configured shields, thereby providing protection against side-reading. The vortex magnetization is accomplished by first magnetizing the free layer in a uniform vertical field, then applying a vertical current while the field is still present.Type: GrantFiled: March 27, 2008Date of Patent: September 13, 2011Assignee: Headway Technologies, Inc.Inventors: Tai Min, Pokang Wang, Min Li, Otto Vogeli
-
Method for making a scissoring-type current-perpendicular-to-the-plane (CPP) magnetoresistive sensor
Patent number: 8015694Abstract: A “scissoring-type” current-perpendicular-to-the-plane (CPP) magnetoresistive sensor with dual ferromagnetic sensing or free layers separated by a nonmagnetic spacer layer has improved stability as a result of etch-induced uniaxial magnetic anisotropy in each of the free layers. Each of the two ferromagnetic free layers has an etch-induced uniaxial magnetic anisotropy and an in-plane magnetic moment substantially parallel to its uniaxial anisotropy in the quiescent state, i.e., the absence of an applied magnetic field. The etch-induced uniaxial anisotropy of each of the free layers is achieved either by direct ion etching of each of the free layers, and/or by ion etching of the layer on which each of the free layers is deposited. A strong magnetic anisotropy is induced in the free layers by the etching, which favors generally orthogonal orientation of the two free layers in the quiescent state.Type: GrantFiled: December 18, 2007Date of Patent: September 13, 2011Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Matthew J. Carey, Jeffrey R. Childress, Stefan Maat, Neil Smith -
Patent number: 8018693Abstract: A magnetic detector includes a magnetoresistive element and an impact sensor. The magnetoresistive element has a plurality of element-constituent layers that are stacked and include a free layer having a magnetization direction that changes in response to a magnetic field to be detected by the magnetic detector. The impact sensor has a plurality of sensor-constituent layers that are made of materials the same as those of the element-constituent layers and stacked in the same order as the element-constituent layers. The plurality of sensor-constituent layers include an impact detecting layer corresponding to the free layer and having a magnetization direction that changes by an inverse magnetostrictive effect in response to distortion created in the impact detecting layer by an impact received by the magnetic detector. The impact detecting layer exhibits a greater amount of change in magnetization direction when the magnetic detector receives an impact, compared with the free layer.Type: GrantFiled: January 21, 2009Date of Patent: September 13, 2011Assignee: TDK CorporationInventor: Takumi Yanagisawa
-
Patent number: 8013407Abstract: There is provided a magnetic memory device stable in write characteristics. The magnetic memory device has a recording layer. The planar shape of the recording layer has the maximum length in the direction of the easy-axis over a primary straight line along the easy-axis, and is situated over a length smaller than the half of the maximum length in the direction perpendicular to the easy-axis, and on the one side and on the other side of the primary straight line respectively, the planar shape has a first part situated over a length in the direction perpendicular to the easy-axis, and a second part situated over a length smaller than the length in the direction perpendicular to the easy-axis. The outer edge of the first part includes only a smooth curve convex outwardly of the outer edge.Type: GrantFiled: March 6, 2009Date of Patent: September 6, 2011Assignee: Renesas Electronics CorporationInventors: Takashi Takenaga, Takeharu Kuroiwa, Hiroshi Takada, Shuichi Ueno, Kiyoshi Kawabata
-
Patent number: 8014108Abstract: The invention provides a magnetoresistive device of the CPP (current perpendicular to plane) structure, comprising a magnetoresistive unit, and a first shield layer and a second shield layer which are located and formed such that the magnetoresistive unit is sandwiched between them from above and below, with a sense current applied in the stacking direction, wherein said magnetoresistive unit comprises a non-magnetic intermediate layer, and a first ferromagnetic layer and a second ferromagnetic layer stacked and formed such that said nonmagnetic intermediate layer is sandwiched between them.Type: GrantFiled: February 8, 2008Date of Patent: September 6, 2011Assignee: TDK CorporationInventors: Koji Shimazawa, Tsutomu Chou, Daisuke Miyauchi
-
Patent number: 8011084Abstract: A method for manufacturing a manufacturing a magnetoresistive sensor that allows the sensor to be constructed with a very narrow and well controlled track width. The method includes depositing a layer of diamond like carbon over a series of sensor layers. A first mask is then formed to define a sensor, and an ion milling is performed to remove sensor material not protected by the first mask. Then, a second mask is formed, and a hard bias layer is deposited to the thickness of the sensor layers. The second mask is then lifted off and a CMP is performed to remove the first mask structure. Because all areas other than the area directly over the sensor are substantially planar a quick, gentle CMP can be used to remove the first mask layer even if the first mask is small, such as for definition of a very narrow track-width sensor.Type: GrantFiled: July 31, 2008Date of Patent: September 6, 2011Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Quang Le, Jui-Lung Li
-
Patent number: 8013408Abstract: A magneto-resistive device has a magnetic free layer (33), a magnetic pinned layer (31) having a magnetic moment larger than that of the magnetic free layer, and an intermediate layer (32) provided between the magnetic free layer and the magnetic pinned layer. The negative-resistance device is characterized in that the negative-resistance device shows negative resistance by making the magnetic free layer continually change the magnetization direction along with the increase of the voltage which is applied to a magneto-resistive device so that electrons flow into the negative-resistance device from a magnetic free layer side.Type: GrantFiled: May 19, 2009Date of Patent: September 6, 2011Assignee: Canon Anelva CorporationInventors: Hiroki Maehara, Hitoshi Kubota, Akio Fukushima, Shinji Yuasa, Yoshishige Suzuki, Yoshinori Nagamine
-
Patent number: 7999338Abstract: A magnetic cell includes a ferromagnetic free layer having a free magnetization orientation direction and a first ferromagnetic pinned reference layer having a first reference magnetization orientation direction that is parallel or anti-parallel to the free magnetization orientation direction. A first oxide barrier layer is between the ferromagnetic free layer and the first ferromagnetic pinned reference layer. The magnetic cell further includes a second ferromagnetic pinned reference layer having a second reference magnetization orientation direction that is orthogonal to the first reference magnetization orientation direction. The ferromagnetic free layer is between the first ferromagnetic pinned reference layer and the second ferromagnetic pinned reference layer.Type: GrantFiled: July 13, 2009Date of Patent: August 16, 2011Assignee: Seagate Technology LLCInventors: Yuankai Zheng, Zheng Gao, Wenzhong Zhu, Wonjoon Jung, Haiwen Xi
-
Patent number: 8000065Abstract: A magnetoresistive element includes: a detection surface that receives a magnetic field to be detected; a free layer made of a ferromagnetic material, having an end face located in the detection surface, and exhibiting a change in magnetization direction in response to the magnetic field to be detected; a pinned layer made of a ferromagnetic material, disposed away from the detection surface, and having a fixed magnetization direction; and a coupling portion made of a nonmagnetic material and coupling the free layer to the pinned layer. The coupling portion includes a nonmagnetic conductive layer that allows electrons to be conducted while conserving their spins.Type: GrantFiled: January 28, 2009Date of Patent: August 16, 2011Assignee: TDK CorporationInventor: Hiroshi Yamazaki
-
Patent number: 8000066Abstract: The thickness of the semiconductor layer forming a part of the spacer layer is set in the thickness range for a transitional area showing conduction performance halfway between ohmic conduction and semi-conductive conduction in relation to the junction of the semiconductor layer with the first nonmagnetic metal layer and the second nonmagnetic metal layer. This permits the specific resistance of the spacer layer to be greater than that of an ohmic conduction area, so that spin scattering and diffusion depending on a magnetized state increases, resulting in an increase in the MR ratio. The CPP-GMR device can also have a suitable area resistivity (AR) value. If the device can have a suitable area resistivity and a high MR ratio, it is then possible to obtain more stable output power in low current operation. The device is also lower in resistance than a TMR device, so that significant noise reductions are achievable.Type: GrantFiled: November 5, 2007Date of Patent: August 16, 2011Assignee: TDK CorporationInventors: Tomohito Mizuno, Yoshihiro Tsuchiya, Kei Hirata
-
Patent number: 7999337Abstract: Apparatus and associated method for writing data to a non-volatile memory cell, such as spin-torque transfer random access memory (STRAM). In accordance with some embodiments, a resistive sense element (RSE) has a heat assist region, magnetic tunneling junction (MTJ), and pinned region. When a first logical state is written to the MTJ with a spin polarized current, the pinned and heat assist regions each have a substantially zero net magnetic moment. When a second logical state is written to the MTJ with a static magnetic field, the pinned region has a substantially zero net magnetic moment and the heat assist region has a non-zero net magnetic moment.Type: GrantFiled: July 13, 2009Date of Patent: August 16, 2011Assignee: Seagate Technology LLCInventors: Yuankai Zheng, Xiaohua Lou, Haiwen Xi, Michael Xuefei Tang
-
Patent number: 7989223Abstract: A spin injection device capable of spin injection magnetization reversal at low current density, a magnetic apparatus using the same, and magnetic thin film using the same, whereby the spin injection device (14) including a spin injection part (1) comprising a spin polarization part (9) including a ferromagnetic fixed layer (26) and an injection junction part (7) of nonmagnetic layer, and a ferromagnetic free layer (27) provided in contact with the spin injection part (1) is such that in which the nonmagnetic layer (7) is made of either an insulator (12) or a conductor (25), a nonmagnetic layer (28) is provided on the surface of the ferromagnetic free layer (27), electric current is flown in the direction perpendicular to the film surface of the spin injection device (14), and the magnetization of the ferromagnetic free layer (27) is reversed. This is applicable to such various magnetic apparatuses and magnetic memory devices as super gigabit large capacity, high speed, non-volatile MRAM and the like.Type: GrantFiled: February 2, 2009Date of Patent: August 2, 2011Assignee: Japan Science and Technology AgencyInventors: Kouichiro Inomata, Nobuki Tezuka
-
Patent number: 7986498Abstract: A high performance TMR element is fabricated by inserting an oxygen surfactant layer (OSL) between a pinned layer and AlOx tunnel barrier layer in a bottom spin valve configuration. The pinned layer preferably has a SyAP configuration with an outer pinned layer, a Ru coupling layer, and an inner pinned layer comprised of CoFeXBY/CoFeZ wherein x=0 to 70 atomic %, y=0 to 30 atomic %, and z=0 to 100 atomic %. The OSL is formed by treating the CoFeZ layer with oxygen plasma. The AlOx tunnel barrier has improved uniformity of about 2% across a 6 inch wafer and can be formed from an Al layer as thin as 5 Angstroms. As a result, the Hin value can be decreased by ? to about 32 Oe. A dR/R of 25% and a RA of 3 ohm-cm2 have been achieved for TMR read head applications.Type: GrantFiled: January 27, 2009Date of Patent: July 26, 2011Assignee: Headway Technologies, Inc.Inventors: Hui-Chuan Wang, Tong Zhao, Min Li, Kunliang Zhang
-
Patent number: 7986481Abstract: Provided is a magnetic reproducing method that enables a thin-film magnetic head including a head element for reading data signals which has a noise in its output due to a low temperature to bring out an excellent read characteristic in which the noise is suppressed even under the use environment with the low temperature. The magnetic reproducing method comprises the steps of: heating a head element for reading data signals which has a noise in its output due to a low temperature; and performing a read operation by using the head element for reading data signals under condition that the head element is increased in temperature.Type: GrantFiled: August 8, 2007Date of Patent: July 26, 2011Assignees: TDK Corporation, SAE Magnetics (H.K.) Ltd.Inventors: Noboru Yamanaka, Susumu Nagatsuka, Yoshihiro Kudo, Eric Cheuk Wing Leung, Chris Chiu Ming Leung, Leo Wai Kay Lau, Charles Kin Chiu Wong
-
Patent number: 7986497Abstract: The invention is a magnetoresistive read head with an MTJ configuration having an ultra-thin tunneling barrier layer with low resistance and high breakdown strength. The barrier layer is formed by natural oxidation of an ultra-thin (two atomic layers) Al or Hf—Al layer deposited on an electrode whose surface has first been treated to form an oxygen surfactant layer. The oxygen within the surfactant layer is first adsorbed within the ultra-thin layer and the layer is subsequently naturally oxidized to produce a uniform and stable Al2O3 stoichiometry (or HfO stoichiometry) in the tunneling barrier layer.Type: GrantFiled: September 4, 2007Date of Patent: July 26, 2011Assignee: Headway Technologies, Inc.Inventors: Cheng T. Horng, Ru-Ying Tong
-
Patent number: 7982996Abstract: A microwave-assisted magnetic recording (MAMR) write head and system has a spin-torque oscillator (STO) located between the write pole of the write head and a trailing shield that alters the write field from the write pole. The STO is a stack of layers whose planes lie generally parallel to the X-Y plane of an X-Y-Z coordinate system, the stack including a ferromagnetic polarizer layer, a free ferromagnetic layer, and a nonmagnetic electrically conductive spacer between the polarizer layer and the free layer. In the presence of the write field from the write pole the polarizer layer has its magnetization oriented at an angle between 20 and 80 degrees, preferably between 30 and 70 degrees, with the Z-axis. In the presence of a direct electrical current through the STO stack, the free layer magnetization rotates or precesses about the Z-axis with a non-zero angle to the Z-axis.Type: GrantFiled: December 7, 2009Date of Patent: July 19, 2011Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Neil Smith, Petrus Antonius VanDerHeijden
-
Patent number: 7978443Abstract: A TMR element includes a lower magnetic layer, an upper magnetic layer, and a tunnel barrier layer of crystalline insulation material sandwiched between the lower magnetic layer and the upper magnetic layer. The lower magnetic layer includes a first magnetic layer and a second magnetic layer sandwiched between the first magnetic layer and the tunnel barrier layer. The second magnetic layer is formed from a magnetic material containing at least one of Fe, Co and Ni.Type: GrantFiled: November 26, 2007Date of Patent: July 12, 2011Assignee: TDK CorporationInventors: Satoshi Miura, Takumi Yanagisawa
-
Patent number: 7978442Abstract: A novel CCP scheme is disclosed for a CPP-GMR sensor in which an amorphous metal/alloy layer such as Hf is inserted between a lower Cu spacer and an oxidizable layer such as Al, Mg, or AlCu prior to performing a pre-ion treatment (PIT) and ion assisted oxidation (IAO) to transform the amorphous layer into a first metal oxide template and the oxidizable layer into a second metal oxide template both having Cu metal paths therein. The amorphous layer promotes smoothness and smaller grain size in the oxidizable layer to minimize variations in the metal paths and thereby improves dR/R, R, and dR uniformity by 50% or more. An amorphous Hf layer may be used without an oxidizable layer, or a thin Cu layer may be inserted in the CCP scheme to form a Hf/PIT/IAO or Hf/Cu/Al/PIT/IAO configuration. A double PIT/IAO process may be used as in Hf/PIT/IAO/Al/PIT/IAO or Hf/PIT/IAO/Hf/PIT/IAO schemes.Type: GrantFiled: October 3, 2007Date of Patent: July 12, 2011Assignees: TDK Corporation, Kabushiki Kaisha ToshibaInventors: Kunliang Zhang, Min Li, Yue Liu, Hideaki Fukuzawa, Hiromi Yuasa
-
Publication number: 20110164338Abstract: A magnetic tunnel junction transistor (MTJT) device includes a source-drain region comprising a source electrode and a drain electrode, a double MTJ element formed between the source electrode and the drain electrode and comprising a free magnetic layer at a center region thereof, and a gate region adjacent to the source-drain region and comprising an insulating barrier layer formed on an upper layer of the double MTJ element and a gate electrode formed on the insulating barrier layer. The MTJT device switches a magnetization orientation of the free magnetic layer by application of a gate voltage to the gate electrode, thereby changing a resistance of the source-drain region.Type: ApplicationFiled: January 4, 2010Publication date: July 7, 2011Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventor: Daniel C. Worledge
-
Patent number: 7974048Abstract: The invention provides a magneto-resistive effect device of the CPP (current perpendicular to plane) structure, having a magneto-resistive effect unit, and a first shield layer and a second shield layer located and formed such that the magneto-resistive effect unit is sandwiched between them, with a sense current applied in a stacking direction.Type: GrantFiled: November 28, 2007Date of Patent: July 5, 2011Assignee: TDK CorporationInventors: Koji Shimazawa, Daisuke Miyauchi, Yoshihiro Tsuchiya, Takahiko Machita, Shinji Hara
-
Patent number: 7969693Abstract: A tunnel magnetoresistive sensor includes a pinned magnetic layer, an insulating barrier layer formed of Mg—O, and a free magnetic layer. A barrier-layer-side magnetic sublayer constituting at least part of the pinned magnetic layer and being in contact with the insulating barrier layer includes a first magnetic region formed of CoFeB or FeB and a second magnetic region formed of CoFe or Fe. The second magnetic region is disposed between the first magnetic region and the insulating barrier layer.Type: GrantFiled: September 19, 2007Date of Patent: June 28, 2011Assignee: Alps Electric Co., Ltd.Inventors: Kazuaki Ikarashi, Eiji Umetsu, Kenichi Tanaka, Kazumasa Nishimura, Masamichi Saito, Yosuke Ide, Ryo Nakabayashi, Yoshihiro Nishiyama, Hidekazu Kobayashi, Naoya Hasegawa
-
Publication number: 20110141613Abstract: According to one embodiment, a method for producing a Tunneling Magnetoresistance (TMR) read head includes forming a fixed layer, forming an insulating barrier layer above the fixed layer, forming a free layer above the insulating barrier layer, and annealing the free layer, the fixed layer, and the insulating barrier layer. The fixed layer includes a first ferromagnetic layer having a CoxFe (0?x?15) interface layer and a Co-based amorphous metallic layer between the CoxFe interface layer and the insulating barrier layer, an antiparallel coupling layer below the first ferromagnetic layer, and a second ferromagnetic layer below the antiparallel coupling layer. In another embodiment, a TMR read head includes the layers described above, and may be included in a magnetic data storage system.Type: ApplicationFiled: November 17, 2010Publication date: June 16, 2011Applicant: Hitachi Global Storage Technologies Netherlands B. V.Inventors: Koji Sakamoto, Koichi Nishioka
-
Patent number: 7961442Abstract: A tunneling magnetic detecting element includes an insulating barrier layer having a layered structure including a Ti—O sublayer and a Ta—O sublayer. The Ta concentration in the insulating barrier layer is set to be more than 0 at % but not more than about 7 at % with respect to a total of 100 at % of Ti and Ta constituting the insulating barrier layer.Type: GrantFiled: November 29, 2007Date of Patent: June 14, 2011Assignee: TDK CorporationInventors: Kazumasa Nishimura, Ryo Nakabayashi, Naoya Hasegawa, Masamichi Saito, Yosuke Ide, Masahiko Ishizone
-
Patent number: 7957109Abstract: A tunnel magnetoresistance effect magnetic head having between magnetic shield layers, an antiferromagnetic layer, a pinned layer which has the direction of magnetization pinned by exchange coupling with the antiferromagnetic layer, an insulating layer, and a free layer whose direction of magnetization rotates relatively to external magnetic fields, wherein the antiferromagnetic layer is of an antiferromagnetic substance composed mainly of IrMn, the pinned layer is made up of a first pinned layer of CoFe alloy in contact with the antiferromagnetic layer and a second pinned layer of CoFeB alloy which is antiferromagnetically coupled with the first pinned layer, and the first and second pinned layers have the amount of magnetization such that the difference M1?M2 is in the range of 0<M2?M1<0.5 (nm·T) and also have the magnetostriction constants such that the difference |?1??2| is no larger than 5.0×10?6.Type: GrantFiled: September 11, 2007Date of Patent: June 7, 2011Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Naoki Koyama, Koichi Nishioka, Kouji Okazaki, Shuichi Kojima, Azusa Hori, Satoshi Shigematsu, Yukimasa Okada
-
Patent number: 7957108Abstract: An MR element includes a free layer having a direction of magnetization that changes in response to an external magnetic field, a pinned layer having a fixed direction of magnetization, and a spacer layer disposed between these layers. The spacer layer includes a first region, a second region and a third region that are each in the form of a layer and that are arranged in a direction intersecting the plane of each of the foregoing layers. The second region is sandwiched between the first region and the third region. The first region and the third region are each composed of an oxide semiconductor, and the second region includes at least a nonmagnetic conductor phase.Type: GrantFiled: August 8, 2007Date of Patent: June 7, 2011Assignee: TDK CorporationInventors: Tsutomu Chou, Tomohito Mizuno
-
Patent number: 7950135Abstract: A manufacturing method of an MR element in which current flows in a direction perpendicular to layer planes, includes a step of forming on a lower electrode layer an MR multi-layered structure with side surfaces substantially perpendicular to the layer lamination plane, a step of forming a first insulation layer on at least the side surfaces of the formed MR multi-layered structure, a step of forming a second insulation layer and a magnetic domain control bias layer on the lower electrode layer, and a step of forming an upper electrode layer on the MR multi-layered structure and the magnetic domain control bias layer.Type: GrantFiled: May 31, 2007Date of Patent: May 31, 2011Assignee: TDK CorporationInventors: Takeo Kagami, Takayasu Kanaya
-
Patent number: 7948717Abstract: A magneto-resistance effect element includes a first magnetic layer of which a magnetization direction is fixed; a second magnetic layer of which a magnetization direction is fixed; an intermediate layer which is provided between the first magnetic layer and the second magnetic layer; and a pair of electrodes for flowing a current perpendicular to a film surface of the resultant laminated body comprised of the first magnetic layer, the second magnetic layer and the intermediate layer. The intermediate layer includes insulating portions and metallic portions containing at least one selected from the group consisting of Fe, Co, Ni, Cr and the metallic portions are contacted with the first magnetic layer and the second magnetic layer.Type: GrantFiled: September 7, 2007Date of Patent: May 24, 2011Assignee: Kabushiki Kaisha ToshibaInventors: Hiromi Yuasa, Hideaki Fukuzawa, Yoshihiko Fuji
-
Patent number: 7944736Abstract: The device comprises two magnetoresistive elements (10, 20) placed relative to each other in magnetostatic interaction in such a manner that a magnetic flux passing between these elements (10, 20) closes through soft ferromagnetic layers (26, 27) of said elements (10, 20). A write device (15) is associated with the elements (10, 20) to control the magnetization of each soft layer (26, 27). A read conductor line (11, 12, 13, 14) is associated with each magnetoresistive element (10, 20) to detect the magnetic state of the soft layer (26, 27) by measuring the corresponding magnetoresistance. The soft ferromagnetic layers (26, 27) of the elements (10, 20) remain oriented substantially in antiparallel relative to each other, while the hard ferromagnetic layers (24) of said elements (10, 20) are oriented substantially in parallel.Type: GrantFiled: July 26, 2006Date of Patent: May 17, 2011Assignee: Commissariat a l'Energie Atomique et aux Energies AlternativesInventors: Bernard Dieny, Virgile Javerliac
-
Patent number: 7939188Abstract: A magnetic stack having a free layer having a switchable magnetization orientation, a reference layer having a pinned magnetization orientation, and a barrier layer therebetween. The stack includes an annular antiferromagnetic pinning layer electrically isolated from the free layer and in physical contact with the reference layer. In some embodiments, the reference layer is larger than the free layer.Type: GrantFiled: July 13, 2009Date of Patent: May 10, 2011Assignee: Seagate Technology LLCInventors: Haiwen Xi, Antoine Khoueir, Brian Lee, Pat Ryan, Michael Tang, Insik Jin, Paul E. Anderson
-
Publication number: 20110102948Abstract: A method and system for providing a magnetic junction usable in a magnetic memory are described. The magnetic junction includes first and second pinned layers, first and second nonmagnetic spacer layers, and a free layer. The first pinned layer has a first pinned layer magnetic moment and is nonmagnetic layer-free. The first nonmagnetic spacer layer resides between the first pinned and free layers. The free layer resides between the first and second nonmagnetic spacer layers. The second pinned layer has a second pinned layer magnetic moment and is nonmagnetic layer-free. The second nonmagnetic spacer layer resides between the free and second pinned layers. The first and second pinned layer magnetic moments are antiferromagnetically coupled and self-pinned. The magnetic junction is configured to allow the free layer to be switched between stable magnetic states when a write current is passed through the magnetic junction.Type: ApplicationFiled: October 30, 2009Publication date: May 5, 2011Applicant: GRANDIS, INC.Inventors: Dmytro Apalkov, Vladimir Nikitin, David Druist, Steven M. Watts
-
Publication number: 20110102949Abstract: 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: ApplicationFiled: November 3, 2009Publication date: May 5, 2011Applicant: WESTERN DIGITAL (FREMONT), LLCInventors: LU YUAN, JIAN X. SHEN, GEOFFREY W. ANDERSON, CHRISTOPHER NG
-
Patent number: 7935435Abstract: A magnetic tunnel junction cell having a free layer, a ferromagnetic pinned layer, and a barrier layer therebetween. The free layer has a central ferromagnetic portion and a stabilizing portion radially proximate the central ferromagnetic portion. The construction can be used for both in-plane magnetic memory cells where the magnetization orientation of the magnetic layer is in the stack film plane and out-of-plane magnetic memory cells where the magnetization orientation of the magnetic layer is out of the stack film plane, e.g., perpendicular to the stack plane.Type: GrantFiled: September 19, 2008Date of Patent: May 3, 2011Assignee: Seagate Technology LLCInventors: Kaizhong Gao, Haiwen Xi
-
Publication number: 20110096443Abstract: A MTJ for a spintronic device is disclosed and includes a thin composite seed layer made of at least Ta and a metal layer having fcc(111) or hcp(001) texture as in Ta/Ti/Cu to enhance perpendicular magnetic anisotropy (PMA) in an overlying laminated layer with a (CoFe/Ni)X, (Co/NiFe)X, (Co/NiCo)X, (CoFe/NiFe)X, or (CoFe/NiCo)X composition where x is from 5 to 30. In one embodiment, a CPP-TMR spin valve has one or both of a laminated free layer and laminated reference layer with the aforementioned compositions. The MTJ includes an interfacial layer made of CoFeB, CoFeB/CoFe, or CoFe/CoFeB between each laminated structure and the tunnel barrier. The laminated layers are deposited by a low power and high Ar pressure process to avoid damaging interfaces between adjoining layers. Annealing occurs at 220° C. to 400° C. A laminated layer with high PMA may also be included in one or more layers of a spin transfer oscillator.Type: ApplicationFiled: October 26, 2009Publication date: April 28, 2011Inventors: Kunliang Zhang, Min Li, Pokang Wang, Yuchen Zhou, Cheng T. Horng, Ru-Ying Tong
-
Patent number: 7933100Abstract: A tunneling magnetic sensor includes a pinned magnetic layer of which the magnetization is pinned in one direction, an insulating barrier layer, and a free magnetic layer of which the magnetization is varied by an external magnetic field, these layers being arranged in that order from the bottom. A first protective layer made of magnesium (Mg) is disposed on the free magnetic layer. The tunneling magnetic sensor has a larger change in reluctance as compared to conventional magnetic sensors including no first protective layers or including first protective layers made of Al, Ti, Cu, or an Ir—Mn alloy. The free magnetic layer has lower magnetostriction as compared to free magnetic layers included in the conventional magnetic sensors.Type: GrantFiled: August 2, 2007Date of Patent: April 26, 2011Assignee: TDK CorporationInventors: Ryo Nakabayashi, Kazumasa Nishimura, Yosuke Ide, Masahiko Ishizone, Masamichi Saito, Naoya Hasegawa