Ferromagnetic Patents (Class 204/192.2)
  • Publication number: 20080206600
    Abstract: An epitaxial Ni3FeN film with unique magnetic properties such as single magnetic domain (even in a large scale 0.5?×0.5?), which rotates coherently in response to the desired switching field with a very sharp transition is described. The magnetic hysteresis loop of this new magnetic nitride is close to the perfect ideal square with the same value of saturation magnetization, remnant magnetization, and magnetization right before switching (domain reversal). The switching field is tunable which make this material more attractive for magneto-resistive devices such as MRAM's, read heads and magnetic sensors.
    Type: Application
    Filed: February 26, 2008
    Publication date: August 28, 2008
    Applicant: Board of Trustees of Michigan State University
    Inventor: Reza Loloee
  • Patent number: 7413636
    Abstract: A dual spin valve (SV) sensor is provided with a longitudinal bias stack sandwiched between a first SV stack and a second SV stack. The longitudinal bias stack comprises an antiferromagnetic (AFM) layer sandwiched between first and second ferromagnetic layers. The first and second SV stacks comprise antiparallel (AP)-pinned layers pinned by AFM layers made of an AFM material having a higher blocking temperature than the AFM material of the bias stack allowing the AP-pinned layers to be pinned in a transverse direction and the bias stack to be pinned in a longitudinal direction. The demagnetizing fields of the two AP-pinned layers cancel each other and the bias stack provides flux closures for the sense layers of the first and second SV stacks.
    Type: Grant
    Filed: October 24, 2003
    Date of Patent: August 19, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B. V.
    Inventors: Tsann Lin, Daniele Mauri
  • Patent number: 7402226
    Abstract: A method of manufacturing a rare earth permanent magnet comprises the steps of: forming a rare earth magnet by applying mechanical processing to a magnet block material, thereby damaging the surface of the magnet and causing a magnetic characteristic (BH)max of the magnet to deteriorate, followed by transforming a rare earth metal or an alloy thereof into fine particles or a vapor, and allowing the fine particles or vapor to diffuse and permeate the magnet, thereby improving the quality of the damaged magnet surface portion so that the magnetic characteristic (BH)max is recovered.
    Type: Grant
    Filed: March 4, 2004
    Date of Patent: July 22, 2008
    Assignees: Japan Science and Technology Agency, Hitachi Metals, Ltd.
    Inventors: Kenichi Machida, Shunji Suzuki, Eiji Sakaguchi, Naoyuki Ishigaki
  • Patent number: 7399387
    Abstract: A target for sputtering includes a sputtering material layer having tilt surfaces. Sputtering material particles are emitted from the tilt surfaces in directions of their normals. Consequently, even though the target and a substrate are arranged approximately parallel and the axes of the two are coincident with each other, the particles are injected onto the substrate from oblique directions.
    Type: Grant
    Filed: May 27, 2004
    Date of Patent: July 15, 2008
    Assignee: Fuji Electric Device Technology Co., Ltd.
    Inventor: Kazuyoshi Shibata
  • Patent number: 7399386
    Abstract: A magnetic recording medium using a plastic substrate as a non-magnetic substrate includes an adhesive layer that prevents film expansion even under severe conditions. The adhesive layer has a chemical affinity to the plastic substrate and is formed on the surface of the plastic substrate, and an underlayer and subsequent layers are formed over the adhesive layer. A polymerized carbon film is used as the adhesive layer.
    Type: Grant
    Filed: July 17, 2002
    Date of Patent: July 15, 2008
    Assignee: Fuji Electric Device Technology Co., Ltd.
    Inventors: Akira Iso, Makoto Isozaki
  • Patent number: 7390381
    Abstract: An information recording medium that is excellent in repeated-rewriting performance and is deteriorated less in crystallization sensitivity with time is provided, with respect to which high density recording can be carried out. A method of manufacturing the same also is provided. The information recording medium includes a substrate and a recording layer disposed above the substrate. The recording layer contains, as constituent elements, Ge, Sb, Te, Sn, and at least one element M selected from Ag, Al, Cr, Mn, and N and is transformed in phase reversibly between a crystal phase and an amorphous phase by an irradiation of an energy beam.
    Type: Grant
    Filed: December 12, 2003
    Date of Patent: June 24, 2008
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Rie Kojima, Noboru Yamada, Takashi Nishihara
  • Patent number: 7377025
    Abstract: A TMR read head with improved voltage breakdown is formed by laying down the AP1 layer as two or more layers. Each AP1 sub-layer is exposed to a low energy plasma for a short time before the next layer is deposited. This results in a smooth surface, onto which to deposit the tunneling barrier layer, with no disruption of the surface crystal structure of the completed AP1 layer.
    Type: Grant
    Filed: October 29, 2004
    Date of Patent: May 27, 2008
    Assignee: Headway Technologies, Inc.
    Inventors: Tong Zhao, Chyu-Jiuh Torng, Hui-Chuan Wang
  • Patent number: 7361419
    Abstract: A substrate for a perpendicular magnetic recording medium has a soft magnetic underlayer that functions as a soft magnetic backing layer of a perpendicular magnetic recording medium. The substrate for a perpendicular magnetic recording medium has a nonmagnetic base made of Al—Mg alloy or the like. The soft magnetic underlayer is formed of a Ni—P alloy containing phosphorus in a range of 0.5 wt % to 6 wt % formed by electroless plating on the nonmagnetic base. The substrate can also include a nonmagnetic underlayer formed by electroless plating on the base before electroless plating the soft magnetic underlayer. To form the perpendicular magnetic recording medium, the surface of the soft magnetic is textured using free abrasive grains. Thereafter, a nonmagnetic seed layer, a magnetic recording layer, and a protective layer can be formed by sputtering. A soft magnetic supplemental layer also can be formed on the soft magnetic underlayer before forming the seed layer.
    Type: Grant
    Filed: February 4, 2004
    Date of Patent: April 22, 2008
    Assignee: Fuji Electric Device Technology Co., Ltd.
    Inventors: Hiroyuki Uwazumi, Yasushi Sakai, Mitsuo Masuda, Norihiko Nakajima
  • Patent number: 7354505
    Abstract: An epitaxial Ni3FeN film with unique magnetic properties such as single magnetic domain (even in a large scale 0.5?×0.5?), which rotates coherently in response to the desired switching field with a very sharp transition is described. The magnetic hysteresis loop of this new magnetic nitride is close to the perfect ideal square with the same value of saturation magnetization, remnant magnetization, and magnetization right before switching (domain reversal). The switching field is tunable which make this material more attractive for magneto-resistive devices such as MRAM's, read heads and magnetic sensors.
    Type: Grant
    Filed: August 25, 2004
    Date of Patent: April 8, 2008
    Assignee: Board of Trustees of Michigan State University
    Inventor: Reza Loloee
  • Patent number: 7347353
    Abstract: A method for connecting a magnetic substance target to a backing plate with less variation in plate thickness, characterized in having the steps of connecting the magnetic substance target to an aluminum plate beforehand while maintaining the flatness, connecting the magnetic substance target connected to the aluminum plate to the backing plate while maintaining the flatness, and grinding out the aluminum plate, whereby the flatness of the magnetic substance target can be maintained until the magnetic substance target is connected to the backing plate by a relatively simple operation.
    Type: Grant
    Filed: November 14, 2002
    Date of Patent: March 25, 2008
    Assignee: Nippon Mining & Metals Co., Ltd.
    Inventors: Yasuhiro Yamakoshi, Kenichi Mogaki
  • Publication number: 20080041716
    Abstract: Described herein are photomask blanks and photomasks prepared therefrom, methods for producing the photomask blanks and apparatus used in such methods. In one aspect, there is described methods for preparing photomask blanks having layers with a compositional gradient, i.e., a varying composition through the thickness of the layer. In other aspects, either in conjunction with the above aspects or independently, methods and apparatus are provided which allow more efficient use of a cluster tool for preparing the photomask blanks and performing quality control on them. The inventions find applicability, for example, in preparing binary photomask blanks and phase shift photomask blanks.
    Type: Application
    Filed: August 18, 2006
    Publication date: February 21, 2008
    Inventors: Hakki Ufuk Alpay, Devi Koty, Michael Patrick Goudy, Tit Keung Lau
  • Patent number: 7313056
    Abstract: The magneto-optical recording medium is comprised of a phase pit substrate/dielectric layer/recording layers/dielectric layer/reflection layer and a ROM and RAM can be simultaneously regenerated. The shape of the phase pit is constructed to be 5<100×Ip/Im<22 where Im is a reflection level on the mirror face and Ip is a phase pit signal output of the shortest mark when a regeneration light having polarization in a direction horizontal to the track direction of the medium is irradiated. Since the jitter of both the magneto-optical recording/regeneration signals and phase pit signals can be suppressed within an optimum range, the quality of the regeneration signals when ROM and RAM are simultaneously regenerated can be improved.
    Type: Grant
    Filed: February 4, 2005
    Date of Patent: December 25, 2007
    Assignee: Fujitsu Limited
    Inventor: Tetsuo Hosokawa
  • Patent number: 7311983
    Abstract: A perpendicular magnetic recording medium has a magnetic recording layer and laminated magnetic layers composed of different materials. In a first magnetic layer of the magnetic recording layer, ferromagnetic grains are surrounded by a nonmagnetic grain boundary region composed principally of oxide and/or nitride. In a second magnetic layer of the magnetic recording layer, ferromagnetic grains are surrounded by a nonmagnetic grain boundary region composed principally of chromium. The recording medium has an intermediate layer composed of a material having hcp or fcc structure. Advantageously, a heating process is conducted after forming the first magnetic layer and before forming the second magnetic layer. The medium achieves improvement in electromagnetic conversion characteristics and simultaneously improvement in corrosion resistance to provide a perpendicular magnetic recording medium with high recording density and simultaneously high reliability.
    Type: Grant
    Filed: June 14, 2004
    Date of Patent: December 25, 2007
    Assignee: Fuji Electric Device Technology Co., Ltd.
    Inventors: Sadayuki Watanabe, Yasushi Sakai, Hiroyuki Uwazumi
  • Patent number: 7312958
    Abstract: A method for manufacturing a magnetic disk apparatus having a highly sensitive reproducing head. 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 reaction layer and the ferromagnetic layer. The antiferromagnetic reaction layer is formed of a metallic compound containing oxygen.
    Type: Grant
    Filed: November 28, 2003
    Date of Patent: December 25, 2007
    Assignee: Matsushita Electric Industrial Co., Ltd
    Inventor: Akifumi Aono
  • Patent number: 7294251
    Abstract: A process for producing a master carrier contains steps of: forming a desired pattern on a support to form a resist pattern support; forming a first ferromagnetic thin film on the resist pattern support by a vacuum film forming method; forming a third ferromagnetic thick film on the first ferromagnetic thin film by an electroplating; and peeling the support from the resist pattern support provided with the first ferromagnetic thin film and the third ferromagnetic thick film.
    Type: Grant
    Filed: August 12, 2004
    Date of Patent: November 13, 2007
    Assignee: Fujifilm Corporation
    Inventors: Masakazu Nishikawa, Seiji Kasahara
  • Patent number: 7294242
    Abstract: An apparatus and method for sputter depositing a magnetic film on a substrate to produce a magnetic device such as magnetic recording heads for reading digital information from a storage medium. The apparatus of the invention includes a sputtering chamber containing a target and a substrate, and a magnet array disposed within the chamber to form a substantially parallel magnetic field at a surface of the substrate. The sputtering chamber reduces interference between the magnetron and the magnet array by providing a long throw distance and/or a grounded collimator. The magnet array is preferably a circular ring.
    Type: Grant
    Filed: August 24, 1998
    Date of Patent: November 13, 2007
    Assignee: Applied Materials, Inc.
    Inventors: Imran Hashim, Seh-Kwang Lee, Thomas Brezoczky, Sesh Ramaswami
  • Patent number: 7279690
    Abstract: A lithographic apparatus is arranged to project a beam from a radiation source onto a substrate. The apparatus includes an optical element in a path of the beam, a gas inlet for introducing a gas into the path of the beam so that the gas will be ionized by the beam to create electric fields toward the optical element, and a gas source coupled to the gas inlet for supplying the gas. The gas has a threshold of kinetic energy for sputtering the optical element that is greater than the kinetic energy developed by ions of the gas in the electric fields.
    Type: Grant
    Filed: March 31, 2005
    Date of Patent: October 9, 2007
    Assignee: ASML Netherlands B.V.
    Inventors: Levinus Pieter Bakker, Vadim Yevgenyevich Banine, Vladimir Vitalevitch Ivanov, Konstantin Nikolaevitch Koshelev, Bastiaan Matthias Mertens, Johannes Hubertus Josephina Moors, Frank Jeroen Pieter Schuurmans, Givi Georgievitch Zukavishvili, Bastiaan Theodoor Wolschrijn, Marc Hubertus Lorenz Van Der Velden
  • Patent number: 7273534
    Abstract: In an optical disk substrate film-formation apparatus which prepared an optical disk by forming a thin film on a substrate, the optical disk substrate is held by a holder section. A contact support surface is provided to the holder section which closely contacts at least a portion of the surface of the optical disk substrate rear to the surface where the think film is formed.
    Type: Grant
    Filed: July 22, 2004
    Date of Patent: September 25, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Kazunori Ito, Katsunari Hanaoka, Hiroshi Deguchi, Nobuaki Onagi, Hiroko Tashiro, Kiyoto Shibata, Yasutomo Aman, Hiroshi Miura, Wataru Ohtani, Hajime Yuzurihara, Masaru Shinkai
  • Publication number: 20070218316
    Abstract: A magnetic recording medium according to one aspect of the present invention includes a substrate; an underlayer positioned on the substrate and made of a material having a body-centered-cubic crystalline structure or a B2 crystalline structure; a first intermediate layer positioned on the underlayer and having a hexagonal closest packing crystalline structure, and being made of Co or a Co alloy; a second intermediate layer positioned on the first intermediate layer and having a hexagonal closest packing crystalline structure, and being made of a material selected from the group consisting of Ru, Ti, Re, Zr, Hf, and a Ru alloy; and a magnetic layer positioned on the second intermediate layer and including multiple magnetic grains each having a hexagonal closest packing crystalline structure and an axis of easy magnetization oriented in a direction substantially parallel to a surface of the substrate, wherein the magnetic grains are isolated from each other.
    Type: Application
    Filed: June 26, 2006
    Publication date: September 20, 2007
    Applicant: FUJITSU LIMITED
    Inventor: Akihiro Inomata
  • Patent number: 7270897
    Abstract: A higher value of an anistropic magnetic feild can be acquired by using a magnetic material where Cr is not added as a material of a magnetic layer on which magnetic data is recorded. A magnetic recording medium can be manufactured through the processes of laminating an underlayer cosisting opf Cr-based non-magnetic material on a substrate, and then laminating, on this underlayer, a magnetic layer consisting of an alloy of at least one kind of non-magnetic material that is different from Cr and Co.
    Type: Grant
    Filed: December 7, 2001
    Date of Patent: September 18, 2007
    Assignee: Fujitsu Limited
    Inventor: Ryoichi Mukai
  • Publication number: 20070212573
    Abstract: A novel heat assisted magnetic recording (HAMR) medium and the fabrication method therefor are provided. The exchange coupling effect occurring at the interface of FePt/CoTb double layers is adopted, and thus the resulting magnetic flux would be sufficient enough to be detected and readout under the room temperature. The provided HAMR medium exhibits a relatively high saturation magnetization and perpendicular coercivity, and thus possesses a great potential for the ultra-high density recording application.
    Type: Application
    Filed: August 4, 2006
    Publication date: September 13, 2007
    Inventors: Po-Cheng Kuo, Yen-Hsiang Fang, An-Cheng Sun, Tao-Hsuan Yang, Chun-Yuan Chou, Ching-Ray Chang
  • Publication number: 20070207348
    Abstract: A perpendicular magnetic recording medium is disclosed that includes a substrate, an underlayer formed of one of Ru and a Ru alloy on the substrate, and a recording layer formed on the underlayer. The underlayer includes multiple crystal grains extending in a direction perpendicular to the surface of the substrate, the crystal grains being separated from each other by a first air gap part. The recording layer includes multiple magnetic particles deposited on the crystal grains of the underlayer, the magnetic particles being separated from each other by a second air gap part.
    Type: Application
    Filed: September 12, 2006
    Publication date: September 6, 2007
    Applicant: FUJITSU LIMITED
    Inventor: Ryoichi MUKAI
  • Patent number: 7256971
    Abstract: 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: Grant
    Filed: March 9, 2004
    Date of Patent: August 14, 2007
    Assignee: Headway Technologies, Inc.
    Inventors: Cheng T. Horng, Ru-Ying Tong
  • Patent number: 7251878
    Abstract: A method and apparatus for defining leading edge taper of a write pole tip is disclosed. The fabrication process uses reactive ion etching to fabricate LET with tight control of the placement of LET's edge and to achieve higher angle for providing a higher effective write field at the pole tip while minimizing ATI for high-density perpendicular recording. The placement of a resist's edge is used to define the LET's edge and a CMP process is used to provide a planar surface for the fabrication of the write pole.
    Type: Grant
    Filed: June 30, 2004
    Date of Patent: August 7, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Quang Le, Jui-Lung Li, Yvette Chung Nga Winton, Sue Siyang Zhang, Yi Zheng
  • Publication number: 20070172706
    Abstract: An exemplary magnetic recording medium with a high recording density and a low medium noise is provided. The magnetic recording medium includes a non-magnetic substrate, a soft magnetic layer, an oxygen-containing intermediate layer, and a perpendicular magnetic recording layer, arranged in contact with one another, in that particular order. The perpendicular magnetic recording layer has a composite layer structure with ferromagnetic grains and a matrix of an amorphous carbon-containing structure. The amorphous carbon-containing structure is dispersed so as to essentially surround the individual ferromagnetic grains, within the perpendicular magnetic recording layer. Methods for making such magnetic recording media also are provided.
    Type: Application
    Filed: September 7, 2006
    Publication date: July 26, 2007
    Applicant: HON HAI PRECISION INDUSTRY CO., LTD.
    Inventor: GA-LANE CHEN
  • Patent number: 7244341
    Abstract: A method for making a spin valve includes providing a substrate; depositing a first ferromagnetic layer having a first surface on the substrate; depositing a spacer layer having a second surface; depositing a second ferromagnetic layer, wherein the spacer layer is disposed between the first and second ferromagnetic layers; and exposing one or more of the first and second surfaces to an oxygen partial pressure, then decreasing the oxygen partial pressure before depositing a subsequent layer. One or more of the first and second surfaces may be exposed to an oxygen partial pressure of between about 1×10?7 Torr and about 5×10?5 Torr.
    Type: Grant
    Filed: October 23, 2003
    Date of Patent: July 17, 2007
    Assignee: International Business Machines Corporation
    Inventor: Mustafa Pinarbasi
  • Patent number: 7226674
    Abstract: A magnetic recording medium based on the perpendicular magnetic recording system has a substrate which is formed of a non-magnetic material, a soft magnetic back layer which is formed of a soft magnetic material and which is formed on the substrate, an underlayer which is formed on the soft magnetic back layer, and a recording layer which is formed of an alloy magnetic material which is mainly composed of CoPtCr and contains an oxide, and which is formed on the underlayer. The recording layer is formed of two or more magnetic layers having different oxide contents, and the layer, which is included in the two or more magnetic layers for constructing the recording layer and which is provided on a side nearest to the underlayer, has the highest oxide content in the recording layer. The magnetic recording medium has more excellent magnetic characteristics with less medium noise.
    Type: Grant
    Filed: January 28, 2004
    Date of Patent: June 5, 2007
    Assignee: Hitachi Maxell, Ltd.
    Inventors: Tetsunori Koda, Hideaki Yamanaka, Enji Fujita, Satoshi Matsunuma
  • Patent number: 7204915
    Abstract: A process for fabricating a patterned medium including a dot-forming step for forming a dot array constituted by sample magnetic dots having a predetermined size such as a single domain particle size determined theoretically from the magnetic metal thin for a sample medium having a magnetic metal film formed with the initial conditions; a demagnetization step for AC-demagnetizing the dot array; a ratio measurement step for measuring the ratio of single magnetic domains by observing the magnetic pattern of each of the sample dots after the AC-demagnetization; and an adjustment step for determining conditions of the sputtering apparatus for forming a solid state magnetic metal thin film by adjusting the film-forming conditions such that the ratio of the single magnetic domains equals to or exceeds a predetermined value.
    Type: Grant
    Filed: May 6, 2004
    Date of Patent: April 17, 2007
    Assignee: Fujitsu Limited
    Inventors: Yasuhiro Kitade, Hitoshi Komoriya
  • Patent number: 7201827
    Abstract: A method for forming a bottom spin-valve GMR sensor having ultra-thin layers of high density and smoothness and possessing oxygen surfactant layers as a result of the layers being sputtered in a mixture of Ar and O2. A particularly novel feature of the method is the use of a sputtering chamber with an ultra-low base pressure and correspondingly ultra-low pressure mixtures of Ar and O2 sputtering gas (<0.5 millitorr) in which the admixed oxygen has a partial pressure of less than 5×10?9 torr.
    Type: Grant
    Filed: September 12, 2003
    Date of Patent: April 10, 2007
    Assignee: Headway Technologies, Inc.
    Inventors: Cheng T. Horng, Ru-Ying Tong
  • Patent number: 7198700
    Abstract: An alloy material, a thin film and an optical recording medium to achieve various tasks such as maintenance of a high reflectivity, improved corrosion resistance, simplified production of the alloy, and realization of stability and simplicity/easiness of a sputtering process when being used as a sputtering target. An AgPd alloy including Ag as a main component and Pd in the range of 0.5 to 4.9 atomic % is used as a thin film formation use sputtering target material, with the target material a thin film, that is a reflecting film, constituting an optical recording medium is formed and the optical recording medium containing the reflecting film as a constituent is produced.
    Type: Grant
    Filed: February 4, 2005
    Date of Patent: April 3, 2007
    Assignees: Sony Corporation, Furuyametals Co., Ltd.
    Inventors: Katsuhisa Aratani, Takashi Ueno
  • Patent number: 7192664
    Abstract: The SMNR of a granular perpendicular recording medium is significantly enhanced by incorporating TiO2 at the grain boundaries of the magnetic alloy layer. Embodiments include granular perpendicular recording media comprising CoPt alloys containing 0.1 to 15 at. % TiO2 and a molar ratio of Pt:Co of up to 0.5.
    Type: Grant
    Filed: February 20, 2004
    Date of Patent: March 20, 2007
    Assignee: Seagate Technology LLC
    Inventors: Zhong Wu, Samuel Dacke Harkness, IV
  • Patent number: 7182843
    Abstract: The magnet arrangement and resulting rotating sputtering magnetron design of an embodiment provides magnetic flux density and distribution to penetrate thick production ferrous targets. Further, the magnetic field shape improves target life by more uniformly removing target material.
    Type: Grant
    Filed: November 3, 2004
    Date of Patent: February 27, 2007
    Assignee: Dexter Magnetic Technologies, Inc.
    Inventors: Richard Stelter, Aron Welk, Christopher Padua, Chun Li
  • Patent number: 7175925
    Abstract: A perpendicular magnetic recording medium, comprising: (a) a non-magnetic substrate having a surface; and (b) a layer stack formed over the substrate surface, comprising in overlying sequence from the substrate surface: (i) a magnetically soft underlayer; (ii) an interlayer structure for crystallographically orienting a layer of a perpendicular magnetic recording material formed thereon; and (iii) at least one crystallographically oriented magnetically hard perpendicular recording layer; wherein the magnetically soft underlayer is sputter-deposited at a sufficiently large target-to-substrate spacing and at a sufficiently low gas pressure selected to provide the underlayer with a smooth surface having a low average surface roughness Ra below about 0.3 nm, as measured by Atomic Force Microscopy (AFM).
    Type: Grant
    Filed: September 17, 2003
    Date of Patent: February 13, 2007
    Assignee: Seagate Technology LLC
    Inventors: Qixu David Chen, Thomas P. Nolan, Zhong Stella Wu, Samuel Dacke Harkness, IV, Rajiv Yadav Ranjan
  • Patent number: 7175926
    Abstract: A recording medium, comprising: (a) a substrate having at least one surface; (b) a stacked plurality of thin film layers on the at least one surface and including at least one magnetic or magneto-optical (MO) recording layer; and (c) a protective overcoat layer on an outer surface of an outermost layer of the layer stack, comprising: (i) a first sub-layer layer (c1) of undoped tetrahedral amorphous carbon (ta-C) formed by filtered cathodic arc deposition (FCAD) on the outer surface of the outermost layer of the stacked plurality of thin film layers and having a high mass density of carbon (C) atoms greater than about 2.5 gms/cm3; and (ii) a second sub-layer (c2) of nitrogen-doped tetrahedral amorphous carbon (ta-C:N) formed by FCAD on the undoped ta-C layer and having a high mass density of carbon (C) atoms greater than about 2.0 gms/cm3.
    Type: Grant
    Filed: February 12, 2004
    Date of Patent: February 13, 2007
    Assignee: Seagate Technology LLC
    Inventors: Xiaoding Ma, Michael Joseph Stirniman, Jing Gui
  • Patent number: 7156961
    Abstract: The present invention is to provide a sputtering apparatus and a thin film formation method which make it possible to form respective layers of a multilayer film having a clean interface at a optimum temperature, or which make it possible to continuously carry out the film formation and the surface processing. Another object of this invention is to provide a small sputtering apparatus for forming a multilayer film as compared with prior art apparatus. A sputtering apparatus of this invention comprises a main shaft around which at least one target and at least one surface processing mechanism are installed, a substrate holder holding a substrate or a plurality of substrates arranged facing the target and the surface processing mechanism, and a rotation mechanism to rotate the main shaft or the substrate holder.
    Type: Grant
    Filed: October 24, 2002
    Date of Patent: January 2, 2007
    Assignee: Anelva Corporation
    Inventors: Kenji Okatani, Satoshi Yamada, Yoshiro Hasegawa
  • Patent number: 7147942
    Abstract: The quantity of oxide contained in a magnetic layer is controlled to control the crystal grains and the segregation structure for ensuring low noise characteristic in a granular magnetic layer of a perpendicular magnetic recording medium. The granular magnetic layer consists of ferromagnetic crystal grains and a nonmagnetic grain boundary region mainly of an oxide surrounding the ferromagnetic crystal grains. The perpendicular magnetic recording medium has a nonmagnetic underlayer composed of a metal or alloy having hexagonal closest-packed crystal structure. The ferromagnetic crystal grain is composed of an alloy containing at least cobalt and platinum. The volume proportion of the nonmagnetic grain boundary region mainly of the oxide falls within a range of 15% to 40% of the volume of the total magnetic layer.
    Type: Grant
    Filed: December 9, 2002
    Date of Patent: December 12, 2006
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Hiroyuki Uwazumi, Yasushi Sakai, Tadaaki Oikawa, Miyabi Nakamura
  • Patent number: 7141145
    Abstract: A method of forming a thin film on a substrate/workpiece by sputtering, comprising steps of: (a) providing an apparatus comprising a vacuum chamber including at least one sputtering source and a gas supply means for injecting a gas containing at least one reactive component into said chamber, the gas supply means comprising a plurality of differently-sized outlet orifices adapted for providing substantially the same flow rate of gas from each orifice; (b) providing a substrate/workpiece having at least one surface for formation of a thin film thereon; (c) generating a sputtered particle flux from the at least one sputtering source; (d) injecting the gas containing the at least one reactive component into the chamber via the gas supply means, such that the same gas flow rate is provided at each orifice; and (e) forming a reactively sputtered thin film on the at least one surface of the substrate/workpiece, the reactively sputtered thin film having a substantially uniform content of the at least one reactive
    Type: Grant
    Filed: October 2, 2003
    Date of Patent: November 28, 2006
    Assignee: Seagate Technology LLC
    Inventors: Charles Frederick Brucker, Paul S. McLeod, Chang Yi
  • Patent number: 7128987
    Abstract: Multilayer magnetic structures comprising composite layers and spacer layers are disclosed. The composite layers include a discontinuous magnetic phase such as Co, Ni or Fe platelets, and a continuous nonmagnetic phase such as C, AlOx, SiOx, ZrOx, Cu, Ag and Au. The spacer layers may comprise Pt, Pd, Au or the like. The composite layers and spacer layers may be made by sputtering. The multilayer structures are useful as magnetic recording layers of magnetic recording media. In one embodiment, the recording media comprises a perpendicular magnetic recording medium including a substrate, a soft magnetic underlayer, a seed layer and the multilayer structure.
    Type: Grant
    Filed: January 6, 2003
    Date of Patent: October 31, 2006
    Assignee: Seagate Technology LLC
    Inventors: Rene Johannes Marinus van de Veerdonk, Duane Clifford Karns, Dieter Klaus Weller, Yukiko Kubota
  • Patent number: 7115191
    Abstract: This invention presents a magnetic recording disk where an anisotropy-allowing layer to allow magnetic anisotropy to a magnetic recording layer is provided between a substrate and the magnetic recording layer. This invention also presents a magnetic-recording-disk manufacturing method comprising a step to prepare an anisotropy-allowing layer to allow magnetic anisotropy to a magnetic recording layer, prior to a step to prepare the magnetic recording layer. This invention also presents a magnetic-recording-disk manufacturing system comprising an anisotropy-allowing-layer preparation chamber, in which an anisotropy-allowing layer to allow magnetic anisotropy to a magnetic recording layer is prepared on a substrate, prior to preparation of the magnetic recording layer. In this invention, the anisotropy-allowing layer is made of; nitride of niobium, tantalum, niobium alloy or tantalum alloy, or nitride-including niobium, tantalum, niobium alloy or tantalum alloy.
    Type: Grant
    Filed: March 4, 2002
    Date of Patent: October 3, 2006
    Assignee: Anelva Corporation
    Inventors: Masahiro Shibamoto, Sinji Furukawa, Tetsuya Endoh, Miho Sakai, Naoki Watanabe
  • Patent number: 7077936
    Abstract: A laminate structure includes an antiferromagnetic layer, a pinned magnetic layer, and a seed layer contacting the antiferromagnetic layer on a side opposite to pinned magnetic layer. The seed layer is constituted mainly by face-centered cubic crystals with (111) planes preferentially oriented. The seed layer is preferably non-magnetic. Layers including the antiferromagnetic layer, a free magnetic layer, and layers therebetween, have (111) planes preferentially oriented.
    Type: Grant
    Filed: October 15, 2002
    Date of Patent: July 18, 2006
    Assignee: Alps Electric Co., Ltd.
    Inventors: Masamichi Saito, Naoya Hasegawa, Yosuke Ide, Kenichi Tanaka
  • Patent number: 7056605
    Abstract: A perpendicular magnetic recording medium has high recording density and excellent read-write characteristics. The recording medium has a magnetic layer of a multilayered lamination structure composed of laminated cobalt layers mainly containing cobalt and noble metal layers of platinum or palladium. At least one of the cobalt layers and the noble metal layers contains at least one element selected from the group consisting of Ru, Ta, Nb, Mo, Mn, Cr, Si, and Ni, or an oxide, in a concentration ranging from 1 to 15 mol %. The magnetic layer is formed on an underlayer of ruthenium or the like for reducing magnetic interaction between the magnetic particles in the magnetic layer. The surface of the underlayer is treated for oxygen adsorption before depositing the magnetic layer to suppress magnetic interaction between the magnetic particles in the magnetic layer.
    Type: Grant
    Filed: August 22, 2003
    Date of Patent: June 6, 2006
    Assignee: Fuji Electric Co., Ltd.
    Inventor: Yasuyuki Kawada
  • Patent number: 7041205
    Abstract: High-saturation magnetization composite soft magnetic films can be deposited with sintered targets made of preferably at least two kinds of powders/elements with much lower saturation magnetization than that of the deposited soft magnetic films. Such a high-saturation magnetization composite soft magnetic film can be deposited by sputtering a plurality of species from a sintered target that forms a film of a material of higher saturation magnetization than that of the species.
    Type: Grant
    Filed: September 9, 2003
    Date of Patent: May 9, 2006
    Assignee: Seagate Technology LLC
    Inventors: Shanghsien Rou, Qixu Chen
  • Patent number: 7037595
    Abstract: A thin layer of hafnium oxide or stacking of thin layers comprising hafnium oxide layers for producing surface treatments of optical components, or optical components, in which at least one layer of hafnium oxide is in amorphous form and has a density less than 8 gm/cm3. The layer is formed by depositing on a substrate without energy input to the substrate.
    Type: Grant
    Filed: November 15, 1999
    Date of Patent: May 2, 2006
    Assignee: Commissariat a l'Energie Atomique
    Inventors: Bernard Andre, Jean Dijon, Brigitte Rafin
  • Patent number: 7037413
    Abstract: The present invention provides an optical information medium having excellent weather resistance and repeating characteristics. The optical information medium has a barrier layer between a protective layer and a recording layer. The barrier layer includes GeN or GeON, and at least one element selected from the group consisting of Al, B, Ba, Bi, C, Ca, Ce, Cr, Dy, Eu, Ga, H, In, K, La, Mn, N, Nb, Ni, Pb, Pd, S, Si, Sb, Sn, Ta, Te, Ti, V, W, Yb, Zn and Zr.
    Type: Grant
    Filed: August 10, 2000
    Date of Patent: May 2, 2006
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Mayumi Otoba, Noboru Yamada, Katsumi Kawahara, Hiroyuki Ohta, Eiji Ohno, Ken'ichi Nagata
  • Patent number: 7024756
    Abstract: The method of making a magnetic head assembly includes forming a second pole piece layer that is recessed from a head surface, forming a reactive ion etchable (RIEable) pole tip forming layer on the second pole piece layer, forming an adhesion/stop layer of tantalum (Ta) on the pole tip forming layer, forming a photoresist mask on the adhesion/stop layer with an opening for patterning the adhesion/stop layer and the pole tip forming layer with another opening, reactive ion etching (RIE) through the opening to form the other opening, forming the second pole piece pole tip in the other opening with a top which is above a top of the adhesion/stop layer and chemical mechanical polishing (CMP) the top of the second pole piece pole tip until the CMP contacts the adhesion/stop layer. The invention also includes the magnetic head made by such a process.
    Type: Grant
    Filed: July 30, 2003
    Date of Patent: April 11, 2006
    Assignee: Hitachi Global Storage Technologies Netherlands, B.V.
    Inventors: Quang Le, Jui-lung Li, Jeffrey S. Lille, Son Van Nguyen
  • Patent number: 7011734
    Abstract: A method of manufacturing a semiconductor device has the steps of: (a) evacuating a sputtering chamber to a pressure of 1.5×10?8 torr to 9×10?8 torr and heating a silicon substrate to a temperature of 330° C. to 395° C.; (b) sputtering Co on the heated silicon substrate; (c) after the step (b), forming a cap layer having a small oxygen transmission performance on the silicon substrate without exposing the silicon substrate in air; (d) after the step (c), performing primary annealing; (e) after the step (d), removing the cap layer and unreacted Co; and (f) after the step (e), performing secondary annealing by heating the silicon substrate to a temperature of 450° C. to 750° C.
    Type: Grant
    Filed: October 16, 2003
    Date of Patent: March 14, 2006
    Assignee: Fujitsu Limited
    Inventor: Kazuto Ikeda
  • Patent number: 7007373
    Abstract: A method for making an enhanced spin valve sensor with engineered overlayer for sensing magnetically recorded information on a data storage medium. The method includes forming a ferromagnetic free layer and a ferromagnetic pinned layer sandwiching an electrically conductive spacer layer. An overlayer is formed on the free layer and adapted to decrease free layer magnetic thickness without reducing physical thickness.
    Type: Grant
    Filed: November 18, 2002
    Date of Patent: March 7, 2006
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Witold Kula, Alexander M. Zeltser
  • Patent number: 6979388
    Abstract: A method of influencing variations in composition of thin films is described. The elemental plasma field distribution in sputtering systems is manipulated by generating a nonuniform electric field along a surface of the substrate to alter the composition by differentially re-sputtering the target elements. The nonuniform electric field is used to modulate the kinetic energy of the ions generated in the plasma which strike the thin film's surface. By applying varying electric potentials at a plurality of points on a conductive surface of a substrate, the electric field across the surface of the substrate can be modulated in a variety of patterns. In the preferred embodiment a radial voltage gradient is applied to a conductive surface of a disk on which a magnetic thin film is being formed to radially modulate the platinum content of the magnetic film.
    Type: Grant
    Filed: January 16, 2004
    Date of Patent: December 27, 2005
    Assignee: Hitachi Global Storage Technologies Netherlands, B.V.
    Inventors: Ernesto E. Marinero, Timothy Martin Reith, Hal Jerves Rosen, Brian R. York
  • Patent number: 6977030
    Abstract: A method of manufacture of thin film magnetic disks and other useful articles of similar planar geometry in which a non-magnetic layer is first deposited on one or both sides of the disk or article substrate to mask chemical and mechanically induced heterogeneities introduced by pre-polishing to achieve a smooth finish, typically resulting in cold-working of the surface, and to also bind to the substrate and is then coated with a thin layer of metal selected to either reactively or catalytically initiate smooth, electroless deposition of a non-magnetic nickel alloy which is subsequently polished and coated with additional thin layers to provide magnetic read-write capability. A disk drive using one or more of such disks is provided.
    Type: Grant
    Filed: June 27, 2001
    Date of Patent: December 20, 2005
    Inventor: Leonard Nanis
  • Patent number: 6972157
    Abstract: A magnetic recording medium comprises a substrate, an undercoat layer, a magnetic layer, and a protective film. The undercoat layer and the magnetic layer are provided atop the substrate. The magnetic layer contains a noble metal layer containing Pt or Pd, a cobalt layer containing Co, and a non-magnetic material layer containing C or Si or Ge.
    Type: Grant
    Filed: March 26, 2003
    Date of Patent: December 6, 2005
    Assignees: Waseda University, Showa Denko Kabushiki Kaisha
    Inventors: Tetsuya Osaka, Hiroshi Sakai