Carbon Overcoat (e.g., Graphite, Diamond Like, Doped Carbon, Etc.) Patents (Class 428/833.2)
  • Patent number: 9524742
    Abstract: To provide a CxNyHz film of high density and a deposition method. One aspect of the present invention is a CxNyHz film formed on a substrate to be deposited, wherein x, y and z satisfy formulae (1) to (4) below: 0.4<x<0.7??(1) 0.01<y<0.5??(2) 0?z<0.3??(3) x+y+z=1.
    Type: Grant
    Filed: October 24, 2011
    Date of Patent: December 20, 2016
    Assignee: YOUTEC CO., LTD.
    Inventors: Haruhito Hayakawa, Kouji Abe, Keiichi Terashima, Yuuji Honda
  • Patent number: 9076479
    Abstract: A magnetic recording medium includes a substrate having sequentially formed thereon (a) a magnetic layer; (b) a protective layer having a thickness ranging from 1.0 nm to 2.5 nm and being composed of an amorphous metal layer having a thickness of at least 0.3 nm, the amorphous metal layer being composed of a metal selected from the group consisting of Si, Al, Ge, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and W that is in an amorphous state; (c) a carbon layer formed on the amorphous metal layer and having a thickness of at least 0.3 nm, the carbon layer including amorphous carbon; and (d) a lubricating layer, wherein the carbon layer includes nitrogen atoms in a surface thereof in which a ratio of number of nitrogen atoms to total number of carbon atoms, nitrogen atoms, and oxygen atoms is 14 atomic % or less.
    Type: Grant
    Filed: August 12, 2013
    Date of Patent: July 7, 2015
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventors: Tomonori Katano, Akiyasu Kumagai, Katsumi Taniguchi, Hiromi Ono, Narumi Sato, Shinji Uchida
  • Patent number: 9047905
    Abstract: A recording medium for recording and reproducing information by means of a head which performs information readout and writing based on magnetic principles is disclosed. The medium comprises a magnetic layer formed on a substrate and a protective layer formed on the magnetic layer. The protective layer comprises an underlayer formed on the magnetic layer and includes a material selected from the group consisting of silicon, silicon carbide and germanium. A carbon layer formed on the underlayer includes amorphous carbon containing hydrogen. The amount of hydrogen in the carbon layer is 24.7 at % or higher and 46.8 at % or lower, the thickness of the underlayer is 0.3 nm or greater and 1.8 nm or less, and the thickness of the carbon layer is 0.2 nm or greater and 1.7 nm or less. The medium exhibits corrosion resistance, sliding durability and head flying characteristics, and reduces magnetic spacing while securing reliability.
    Type: Grant
    Filed: July 25, 2012
    Date of Patent: June 2, 2015
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventors: Tomonori Katano, Akiyasu Kumagai, Katsumi Taniguchi, Hiromi Ono, Narumi Sato
  • Publication number: 20150037614
    Abstract: The present disclosure relates to a planarized bit-patterned magnetic medium that has a magnetic layer, including island regions and trench regions, a first carbon layer applied over the magnetic layer, and a second carbon layer applied over the first carbon layer, wherein the second carbon layer has been removed in the island regions. The first carbon layer may have a lower material removal rate when exposed to chemical-mechanical polishing than the second carbon layer. The present disclosure also relates to a method for planarizing a bit-patterned magnetic medium and a slurry composition for the chemical-mechanical polishing of carbon layers, the slurry composition including an oxidizer component, a catalyst component, a particulate component, and a reaction control component.
    Type: Application
    Filed: August 2, 2013
    Publication date: February 5, 2015
    Applicant: HGST Netherlands B.V.
    Inventors: Kurt A. Rubin, Richard L. White, Xiaoping Bian
  • Publication number: 20150017483
    Abstract: Provided herein is a method including oxidizing tops of features of a patterned magnetic layer to form oxidized tops of the features; removing an excess of an applied first protective material down to at least the oxidized tops of the features to form a planarized layer; and applying a second protective material over the planarized layer.
    Type: Application
    Filed: October 24, 2013
    Publication date: January 15, 2015
    Applicant: Seagate Technology LLC
    Inventors: Michael R. Feldbaum, Wago Wago, Bin Lu, David S. Kuo
  • Patent number: 8795857
    Abstract: A perpendicular magnetic recording medium of the invention is characterized by having, on a disk substrate 110, a soft magnetic layer 14, a magnetic recording layer 22, a continuous layer 24 magnetically continuous in the in-plane direction of the substrate, a blocking layer 25 for blocking shock imposed on the continuous layer, and a medium protective layer 28 containing carbon formed on the blocking layer.
    Type: Grant
    Filed: September 24, 2008
    Date of Patent: August 5, 2014
    Assignee: WD Media (Singapore) Pte. Ltd.
    Inventors: Kenji Ayama, Tokichiro Sato, Teiichiro Umezawa, Masafumi Ishiyama
  • Patent number: 8760980
    Abstract: Apparatus for recording data and method for making the same. In accordance with some embodiments, a magnetic recording layer is adapted to store data along perpendicular magnetic domains. A protective overcoat layer is formed on the magnetic recording layer to substantially protect the magnetic recording layer from environmental effects. The protective overcoat layer is made of carbon intermixed with at least one transition metal, such as but not limited to chromium.
    Type: Grant
    Filed: February 26, 2013
    Date of Patent: June 24, 2014
    Assignee: Seagate Technology LLC
    Inventors: Lihong Zhang, Samuel Gan
  • Publication number: 20140002929
    Abstract: A manufacturing method of a magnetic recording medium includes follows: forming a magnetic recording layer on a substrate; forming an under layer and a metal release layer that forms an alloy with the under layer on the magnetic recording layer in this order and forming an alloyed release layer by alloying the under layer and the metal release layer; forming a mask layer on the alloyed release layer; forming a resist layer on the mask layer; providing a protrusion-recess pattern by patterning the resist layer; transferring the protrusion-recess pattern to the mask layer; transferring the protrusion-recess pattern to the alloyed release layer; transferring the protrusion-recess pattern to the magnetic recording layer; dissolving the alloyed release layer by using a stripping solution and removing a layer formed on the alloyed release layer from an upper side of the magnetic recording layer.
    Type: Application
    Filed: October 24, 2012
    Publication date: January 2, 2014
    Inventors: Kazutaka TAKIZAWA, Akira Watanabe, Kaori Kimura, Takeshi Iwasaki, Akihiko Takeo
  • Publication number: 20130337290
    Abstract: A magnetic recording medium and related method of manufacturing a magnetic recording medium that has a protective layer for the magnetic recording medium and that exhibits excellent corrosion resistance in the protective layer. The magnetic recording medium includes on a nonmagnetic substrate a magnetic layer and a protective layer formed on the magnetic layer. The protective layer is formed of a lower layer in contact with the magnetic layer and an upper layer formed on the lower layer. The material used in the lower layer is a metal having a standard electrode potential of ?0.8 to 0.3 V.
    Type: Application
    Filed: April 9, 2013
    Publication date: December 19, 2013
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventor: Yuko NAKAMATA
  • Patent number: 8559136
    Abstract: A magnetic recording medium according to one embodiment includes at least a ground layer above a non-magnetic substrate; a magnetic recording layer above the ground layer; and an overcoat above the magnetic recording layer, the overcoat characterized in that said overcoat is an amorphous carbon film having a ratio of sp3 bonding with respect to sp2 bonding (sp3/(sp2+sp3)) of at least 0.5, and hydrogen content in the overcoat in a center layer thereof in a film thickness direction of said overcoat is from 0.1 atom % to 0.6 atom %. Additional products and methods are also presented.
    Type: Grant
    Filed: November 14, 2012
    Date of Patent: October 15, 2013
    Assignee: HGST Netherlands B.V.
    Inventors: Toru Matsumura, Hiroshi Inaba, Hiroyuki Matsumoto
  • Patent number: 8518563
    Abstract: A magnetic data storage medium may include a substrate, a magnetic recording layer, a protective carbon overcoat, and a monolayer covalently bound to carbon atoms adjacent a surface of the protective carbon overcoat. According to this aspect of the disclosure, the monolayer comprises at least one of hydrogen, fluorine, nitrogen, oxygen, and a fluoro-organic molecule. In some embodiments, a surface of a read and recording head may also include a monolayer covalently bound to carbon atoms of a protective carbon overcoat.
    Type: Grant
    Filed: February 23, 2010
    Date of Patent: August 27, 2013
    Assignee: Seagate Technology LLC
    Inventors: Paul M. Jones, Xiaoping Yan, Lei Li, James Dillon Kiely, Christopher Loren Platt, Michael J. Stirniman, Jiping Yang, Yiao-Tee Hsia
  • Publication number: 20130034746
    Abstract: A recording medium for recording and reproducing information by means of a head which performs information readout and writing based on magnetic principles is disclosed. The medium comprises a magnetic layer formed on a substrate and a protective layer formed on the magnetic layer. The protective layer comprises an underlayer formed on the magnetic layer and includes a material selected from the group consisting of silicon, silicon carbide and germanium. A carbon layer formed on the underlayer includes amorphous carbon containing hydrogen. The amount of hydrogen in the carbon layer is 24.7 at % or higher and 46.8 at % or lower, the thickness of the underlayer is 0.3 nm or greater and 1.8 nm or less, and the thickness of the carbon layer is 0.2 nm or greater and 1.7 nm or less. The medium exhibits corrosion resistance, sliding durability and head flying characteristics, and reduces magnetic spacing while securing reliability.
    Type: Application
    Filed: July 25, 2012
    Publication date: February 7, 2013
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventors: Tomonori KATANO, Akiyasu KUMAGAI, Katsumi TANIGUCHI, Hiromi ONO, Narumi SATO
  • Publication number: 20120196154
    Abstract: Disclosed are a magnetic recording medium for a heat-assisted recording device which has a high SNR at high density and a manufacturing method thereof. The magnetic recording medium includes, in the order recited: a non-magnetic substrate; a magnetic recording layer; a protective layer; and a liquid lubricating layer. The magnetic recording layer has a granular structure formed by a magnetic portion and a non-magnetic portion that surrounds the magnetic portion, the non-magnetic portion having a volume percentage based on the total volume of the granular structure ranging from 15 vol % to 30 vol % and including a carbon-based material. The magnetic recording medium has a surface having an arithmetic mean roughness Ra and an average length of roughness curve elements RSm such that Ra/RSm ranges from 0.05 to 0.15.
    Type: Application
    Filed: January 10, 2012
    Publication date: August 2, 2012
    Applicant: FUJI ELECTRIC CO.,LTD.
    Inventor: Shinji UCHIDA
  • Publication number: 20120154948
    Abstract: In one embodiment, a perpendicular magnetic recording medium includes a substrate, a soft-magnetic underlayer above the substrate, a seed layer above the soft-magnetic underlayer, a first intermediate layer above the seed layer, a second intermediate layer above the first intermediate layer, a recording layer above the second intermediate layer, and a protective layer above the recording layer. The second intermediate layer includes an Ru alloy having an element selected from a group consisting of: Ti in a range from about 20 at. % to about 50 at. %, Nb in a range from about 20 at. % to about 50 at. %, Al in a range from about 20 at. % to about 40 at. %, Ta in a range from about 30 at. % to about 50 at. %, and Si in a range about 20 at. % to about 40 at. %. Other magnetic media and systems using this media are described according to more embodiments.
    Type: Application
    Filed: December 21, 2010
    Publication date: June 21, 2012
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Ichiro Tamai, Yotsuo Yahisa, Akemi Hirotsune, Kiwamu Tanahashi
  • Patent number: 8168312
    Abstract: A magnetic recording medium and a method of manufacturing a magnetic recording medium are provided, in which degradation of wear resistance against a magnetic head and performances of the medium is restrained, and metal dissolving out of the magnetic recording layer and degradation of corrosion resistance due to low coverage of a protective layer are suppressed. The method of manufacturing provides a magnetic recording medium having a convex portion of a magnetic recording layer for recording information and a concave portion without a recording function on a disk substrate. An ALD protective layer is formed on the magnetic recording medium using an ALD method. The magnetic recording medium has a convex portion of a magnetic recording layer for recording information and a concave portion without a recording function on a disk substrate, and has a protective layer formed by an ALD method on the concavo-convex pattern.
    Type: Grant
    Filed: February 5, 2008
    Date of Patent: May 1, 2012
    Assignee: Fuji Electric Co., Ltd.
    Inventor: Michiko Horiguchi
  • Patent number: 8101409
    Abstract: Compositions for promoting growth and/or differentiation of a stem cell are disclosed. The composition comprises: a) a diamond film; b) a stem cell cultured on the diamond film; and c) a medium bathing the stem cell. The stem cell may be a mammalian neural stem cell and the diamond film may comprise a hydrogen-terminated or an oxygen-terminated surface. The hydrogen-terminated surface promotes proliferation and differentiation of a neural stem cell into neurons, and the oxygen-terminated surface promotes a neural stem cell to proliferate and differentiate into oligodendrocytes.
    Type: Grant
    Filed: October 5, 2009
    Date of Patent: January 24, 2012
    Assignees: National Health Research Institutes, National Tsing Hua University
    Inventors: Ing-Ming Chiu, Ying-Chieh Chen, Don-Ching Lee, Nyan-Hwa Tai
  • Patent number: 8014104
    Abstract: A protective bilayer on a magnetic read/write head or magnetic disk is formed as an adhesion enhancing and corrosion resistant underlayer and a protective diamond-like carbon (DLC) overlayer. The underlayer is a transition metal oxynitride, having the general formula MeOxNy, where Me represents a single element or an alloy of the following transition metal elements: Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W, here x can be within the range between 0 and 3 and y is in the range between approximately 0 and 2. Adjusting the values of x and y contributes to such qualities of the protective bilayer as stress compensation, chemical and mechanical stability and low electrical conductivity. Methods of forming the adhesion layer, include reactive ion sputtering, plasma assisted chemical vapor deposition, pulsed laser deposition and plasma immersion ion implantation.
    Type: Grant
    Filed: March 21, 2007
    Date of Patent: September 6, 2011
    Assignee: SAE Magnetics (HK) Ltd.
    Inventors: Shide Cheng, Zhu Feng, Ellis T. Cha
  • Publication number: 20110205665
    Abstract: A magnetic data storage medium may include a substrate, a magnetic recording layer, a protective carbon overcoat, and a monolayer covalently bound to carbon atoms adjacent a surface of the protective carbon overcoat. According to this aspect of the disclosure, the monolayer comprises at least one of hydrogen, fluorine, nitrogen, oxygen, and a fluoro-organic molecule. In some embodiments, a surface of a read and recording head may also include a monolayer covalently bound to carbon atoms of a protective carbon overcoat.
    Type: Application
    Filed: February 23, 2010
    Publication date: August 25, 2011
    Applicant: Seagate Technology LLC
    Inventors: Paul M. Jones, Xiaoping Yan, Lei Li, James Dillon Kiely, Christopher Loren Platt, Michael J. Stirniman, Jiping Yang, Yiao-Tee Hsia
  • Patent number: 7939367
    Abstract: The invention is a method for growing a critical adherent diamond layer on a substrate by Chemical Vapor Deposition (CVD) and the article produced by the method. The substrate can be a compound semiconductor coated with an adhesion layer. The adhesion layer is preferably a dielectric, such as silicon nitride, silicon carbide, aluminum nitride or amorphous silicon, to name some primary examples. The typical thickness of the adhesion layer is one micrometer or less. The resulting stack of layers, (e.g. substrate layer, adhesion layer and diamond layer) is structurally free of plastic deformation and the diamond layer is well adherent to the dielectric adhesion layer such that it can be processed further, such as by increasing the thickness of the diamond layer to a desired level, or by subjecting it to additional thin film fabrication process steps. In addition to preventing plastic deformation of the layer stack, the process also reduces the formation of soot during the CVD process.
    Type: Grant
    Filed: December 18, 2008
    Date of Patent: May 10, 2011
    Assignee: Crystallume Corporation
    Inventors: Firooz Nasser-Faili, Niels Christopher Engdahl
  • Publication number: 20100310904
    Abstract: A magnetic disk is protected by a bilayer. The bilayer is formed as an adhesion enhancing underlayer and a protective diamond-like carbon (DLC) overlayer. The underlayer is formed of an aluminum or alloyed aluminum oxynitride, having the general formula AlOxNy or MezAlOxNy where Mez symbolizes Tiz, Siz or Crz and where x, y and z can be varied within the formation process. By adjusting the values of x and y the adhesion underlayer contributes to such qualities of the protective bilayer as stress compensation, chemical and mechanical stability and low electrical conductivity. Various methods of forming the underlayer are provided, including reactive ion sputtering, plasma assisted chemical vapor deposition, pulsed laser deposition and plasma immersion ion implantation.
    Type: Application
    Filed: August 2, 2010
    Publication date: December 9, 2010
    Inventors: Shide Cheng, Zhu Feng, Ellis T. Cha
  • Patent number: 7826176
    Abstract: A magnetic recording media includes a toroidal substrate, a surface thereof is divided into a recording area located in a central part between an outer peripheral edge and an inner peripheral edge, edge areas located within 100 ?m or more and 2,000 ?m or less from the outer and inner peripheral edges, respectively, and adjacent areas located between the edge areas and the recording area, respectively, a magnetic film on the substrate, and a protective film on the magnetic film, in which the magnetic film is thinner in the edge areas than that in the adjacent areas, and at least a part of the protective film in the edge areas is thicker than that in the adjacent areas.
    Type: Grant
    Filed: March 22, 2007
    Date of Patent: November 2, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Satoshi Shirotori, Masatoshi Sakurai, Akira Kikitsu, Yoshiyuki Kamata, Kaori Kimura
  • Patent number: 7771853
    Abstract: A patterned magnetic medium includes: a substrate; a soft magnetic underlying film, a nonmagnetic film, an intermediate film and a recording layer which are formed on a principal surface of the substrate; a first protective film formed in contact with the recording film; a second protective film formed in contact with the first protective film; and a third protective film formed in contact with the second protective film. Moreover, the recording layer has a pattern structure formed by making a magnetic film come into contact with a concavo-convex pattern of a nonmagnetic material. The first protective film and the third protective film include carbon as the main constituent element and the second protective film is a wet-coated polymer film. High adhesion between carbon and the wet-coated polymer film can prevent peeling off and the wet-coated polymer film as a cushioning material absorbs impact.
    Type: Grant
    Filed: December 14, 2007
    Date of Patent: August 10, 2010
    Assignee: Hitachi, Ltd.
    Inventor: Tomio Iwasaki
  • Patent number: 7682711
    Abstract: A magnetic recording medium is provided which includes a recording layer formed in a concavo-convex pattern including recording elements formed as convex portions, provides a good flying performance of a magnetic head, and has high reliability. A magnetic recording and reproducing apparatus including that magnetic recording medium and a manufacturing method of that magnetic recording medium are also provided. The magnetic recording medium includes: the recording layer formed in a predetermined concavo-convex pattern over a substrate, the recording elements being formed as convex portions of the concavo-convex pattern; filling elements with which concave portions between the recording elements are filled; a conductive film which has a smaller electric resistivity than the filling elements and is formed over the filling elements; and a protective layer which covers the recording elements and the filling elements and is in contact with an upper surface of the conductive film.
    Type: Grant
    Filed: February 13, 2006
    Date of Patent: March 23, 2010
    Assignee: TDK Corporation
    Inventors: Kazuhiro Hattori, Takahiro Suwa
  • Patent number: 7655208
    Abstract: The object of the present invention is to obtain a high quality single crystalline diamond that has less distortion and large area suitable for semiconductor device substrates or an optical component material. The present invention is a single crystalline diamond produced by chemical vapor deposition, wherein, when a linear polarized light which is composed of two linear polarized lights perpendicular to each other is introduced into one main face of the single crystalline diamond, a maximum value of a retardation between the two linear polarized lights perpendicular to each other which come out from an opposite main face is not more than 50 ?m at maximum per a thickness of 100 ?m across an entire of the single crystalline diamond, and also a method for producing the diamond.
    Type: Grant
    Filed: April 12, 2006
    Date of Patent: February 2, 2010
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Kiichi Meguro, Yoshiyuki Yamamoto, Takahiro Imai
  • Publication number: 20090317663
    Abstract: Provided is a magnetic recording medium. The magnetic recording medium includes a substrate, a recording layer disposed on the substrate for magnetic recording, and a carbon protection layer, which includes a carbon layer and a blocking layer disposed in the carbon layer to block infiltration of external impurities, disposed on the recording layer. Since the blocking layer is disposed in the carbon layer, a thickness of the carbon protection layer can be reduced while a sufficient hardness to protect the recording layer can be ensured, and moreover, a softness of the surface of the carbon protection layer can be improved.
    Type: Application
    Filed: June 16, 2009
    Publication date: December 24, 2009
    Applicant: Samsung Electronics Co., Ltd
    Inventors: Sok-hyun KONG, Hyung-ik LEE, Hoo-san LEE, Young-su CHUNG, Seong-yong YOON
  • Publication number: 20090305081
    Abstract: A method for planarizing a magnetic recording disk that has surface features of elevated lands and recessed grooves includes forming two coatings of cured perfluorinated polyether (PFPE) polymers over the surface features. The disk may have a protective carbon overcoat with a surface that replicates the topography of lands and grooves. A liquid functionalized-PFPE is applied over the disk surface and then cured to form a first coating with the functionalized end groups bonding to the carbon overcoat. A liquid non-functionalized-PFPE polymer is then applied over the functionalized-PFPE coating and cured to form a second coating. The combined coatings substantially planarize the disk surface so that there is minimal recession between the top of the coating over the lands and the top of the coating over the grooves.
    Type: Application
    Filed: June 10, 2008
    Publication date: December 10, 2009
    Applicant: HITACHI GLOBAL STORAGE TECHNOLOGIES NETHERLANDS B.V.
    Inventors: Qing Dai, Xing-Cai Guo, Dan Saylor Kercher, Mike Suk
  • Patent number: 7572528
    Abstract: A magnetic recording medium is obtained by easily patterning a magnetic recording layer without deteriorating its electromagnetic conversion characteristics, by forming a silicon-based protective film between the magnetic recording layer and a photoresist, and performing dry etching and oxygen plasma processing.
    Type: Grant
    Filed: May 24, 2005
    Date of Patent: August 11, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takayuki Yamamoto, Masatoshi Sakurai, Yoshiyuki Kamata
  • Patent number: 7537846
    Abstract: A protection layer containing carbon as a major component is deposited by plasma CVD. The protection layer has film quality such that, when a spectrum is obtained by excluding photoluminescence from a Raman spectrum in a wavenumber band from 900 cm?1 to 1800 cm?1 obtained by exciting the protection layer with an argon ion laser beam having a wavelength of 514.5 nm and the spectrum is subjected to waveform separation by the Gaussian function to split a D peak appearing around 1350 cm?1 and a G peak appearing around 1520 cm?1, the ratio Dw/Gw between a half width Dw of the D peak and a half width Gw of the G peak exceeds 0 and is not greater than 2.7.
    Type: Grant
    Filed: November 10, 2004
    Date of Patent: May 26, 2009
    Assignees: Hoya Corporation, Hoya Magnetics Singapore Pte. Ltd.
    Inventors: Masafumi Ishiyama, Kenji Ayama
  • Patent number: 7514163
    Abstract: A magnetic recording medium having excellent durability and corrosion resistance as well as a magnetic recording device equipped with the magnetic recording medium is provided. The protective layer of the magnetic recording medium is composed of two layers, that is, a lower layer contacting with the magnetic layer and an upper layer on the lower layer. The internal stress of the lower layer is made smaller than that of the upper layer, and the surface free energy of the lower layer is made smaller than that of the upper layer.
    Type: Grant
    Filed: November 4, 2004
    Date of Patent: April 7, 2009
    Assignee: Fujitsu Limited
    Inventors: Norikazu Nakamura, Tsukasa Itani, Yukiko Oshikubo, Shinichi Nakayama, Takashi Toyoguchi
  • Patent number: 7391592
    Abstract: A magnetic recording medium having a diamond-like carbon (DLC) film added therein a Group IV element of the periodic table such as silicon, particularly in the vicinity of the boundary between the magnetic material and the formed DLC film. Since a DLC having low friction coefficient can be formed, the centerline average roughness can be reduced to 30 nm or even less. Accordingly, a magnetic recording medium improved in magnetic properties and in lubricity can be obtained.
    Type: Grant
    Filed: July 26, 2006
    Date of Patent: June 24, 2008
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventor: Shigenori Hayashi
  • Patent number: 7357998
    Abstract: A disk substrate for a perpendicular magnetic recording medium comprises a disk base member, a soft magnetic layer formed on the disk base member, and a protection layer formed on the soft magnetic layer. The soft magnetic layer and the protection layer are deposited by sputtering. A perpendicular magnetic recording disk comprises the above-mentioned disk substrate and at least a perpendicular magnetic recording layer formed thereon. The perpendicular magnetic recording layer is deposited on the disk substrate by sputtering after the disk substrate is heated.
    Type: Grant
    Filed: January 16, 2004
    Date of Patent: April 15, 2008
    Assignee: Hoya Corporation
    Inventors: Kong Kim, Junichi Horikawa
  • Patent number: 7214436
    Abstract: A magnetic recording medium of a metal thin-film type, which includes a magnetic layer and a carbon protective layer on a non-magnetic support member, and in which a non-magnetic metal thin-film is provided between the magnetic layer and the carbon protective layer, is provided. The magnetic recording medium thus produced can be run stably.
    Type: Grant
    Filed: May 15, 2003
    Date of Patent: May 8, 2007
    Assignee: Sony Corporation
    Inventors: Ryoichi Hiratsuka, Tomoe Ozaki, Taketoshi Sato, Miho Abiko, Ichiro Kanagawa, Kasumi Suzuki
  • Patent number: 7147943
    Abstract: This magnetic recording medium is characterized in that in the magnetic recording medium having a magnetic layer on a non-magnetic substrate by intercalating at least an under layer, the proportion of functional groups per 100 carbon atoms in a diamond-like carbon protective layer mainly composed of carbon for protecting the magnetic layer exceeds 20%. The bonding force between the protective layer and the lubricating layer of the magnetic recording medium is increased so that under high speed rotation, a decrease in the lubricating layer is not caused so as to provide a magnetic recording apparatus having high reliability.
    Type: Grant
    Filed: May 6, 2003
    Date of Patent: December 12, 2006
    Assignee: Hitachi Global Storage Technologies Japan, Ltd.
    Inventors: Toshinori Ono, Yuuichi Kokaku, Hiroyuki Matsumoto, Hiroshi Tani, Mitsuhiro Shoda, Tomonori Kozaki, Hiroshi Ishikawa, Toru Yatsue, Yoshinori Honda, Shigehiko Fujimaki