Patents by Inventor Katsuro Watanabe

Katsuro Watanabe has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20080218910
    Abstract: Embodiments of the present invention help to reduce etching damage at end parts of a magnetoresistive sensor in ion beam etching. According to one embodiment, ion beam etching (IBE) is used in a magnetoresistive sensor track width forming step. This IBE irradiates Ar ion beam to a substrate in a state that the substrate is inclined and further rotates the substrate about its normal as a rotational axis. In a conventional track width forming step, the IBE irradiates the Ar ion beam to the substrate all the time while the IBE is rotating the substrate. By contrast, the IBE according to embodiments of the present invention irradiates the Ar ion beam to the substrate only in a predetermined specific angular range.
    Type: Application
    Filed: February 4, 2008
    Publication date: September 11, 2008
    Inventors: Shuichi Kojima, Satoru Okamoto, Nobuo Yoshida, Katsuro Watanabe
  • Publication number: 20080212238
    Abstract: Embodiments of the present invention help to efficiently apply a longitudinal biasing with appropriate strength from a longitudinal biasing layer to a free layer even in a small read gap length. According to one embodiment, in the track width direction of the magnetoresistive film, the longitudinal biasing layer excluding its portion close to the magnetoresistive film is made approximately uniform in thickness. An edge toward the magnetoresistive film of the longitudinal biasing layer is positioned more outwardly in the track width direction than an edge in the track width direction of the free layer. A portion closest to the substrate of the interface between the longitudinal biasing layer and the insulator on the track-width sides is positioned lower than the interface between the magnetoresistive film and the lower magnetic shield layer.
    Type: Application
    Filed: January 31, 2008
    Publication date: September 4, 2008
    Inventors: Katsuro Watanabe, Satoru Okamoto, Masahiro Osugi, Koji Okazaki
  • Publication number: 20080062579
    Abstract: Embodiments of the present invention provide a method of fabricating a magnetic head slider realizing high-recording density at high-yields by preventing formation of a short circuit on the air-bearing surface of a magnetic head slider and preventing formation of an oxidized layer with significant film thickness which increases the effective magnetic spacing, on the air-bearing surface of the magnetic head slider. According to one embodiment, after air-bearing surface mechanical lapping of a row bar or a magnetic head slider, cleaning is performed by ion beam bombardment to remove a conductive smear. Oxygen exposure is performed to recover a damaged region which was formed by ion beam bombardment at the end face of an intermediate layer of a magnetoresistive film 5. Thereafter, air-bearing surface protection films are formed and followed by rail formation. If the processes are performed on the row bar, the row bar is cut into individual separated magnetic head sliders.
    Type: Application
    Filed: August 24, 2007
    Publication date: March 13, 2008
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Nobuto Yasui, Katsuro Watanabe, Takateru Seki, Kazuhito Miyata, Tetsuya Matsusaki
  • Patent number: 7333301
    Abstract: A thin-film magnetic head having little temperature rise in the element, good heat dissipation and a short magnetic path length (narrow coil pitch) and manufacturing method for same is provided. To form the coil of the thin-film magnetic head, a lower coil is first formed and after forming alumina and an inorganic compound containing alumina, a trench is formed for the upper coil by reactive ion etching. The lower coil allows uniform etching at this time and functions as a film to prevent loading effects occurring during reactive ion etching. This trench is then plated in copper and chemical mechanical planarization performed to form the upper layer coil as the dual-layer coil of the present invention. Heat from the coil is efficiently radiated towards the substrate by alumina and an inorganic compound containing alumina with good heat propagation.
    Type: Grant
    Filed: August 29, 2003
    Date of Patent: February 19, 2008
    Assignee: Hitachi Global Storage Technologies Japan, Ltd.
    Inventors: Kimitoshi Etoh, Nobuo Yoshida, Moriaki Fuyama, Makoto Morijiri, Kenichi Meguro, Ichiro Oodake, Kazue Kudo, Yohji Maruyama, Katsuro Watanabe
  • Publication number: 20070297097
    Abstract: Embodiments in accordance with the present invention provide a magnetic head of the CPP structure for perpendicular magnetic recording, that is excellent in read performance, and stable in write/read performances by enhancing the external field durability, and further, suppresses deterioration in read sensor property, due to thermal factors. At least either shield layer of a lower magnetic shield layer, and an upper magnetic shield layer, closer to a perpendicular magnetic write head, is made up so as to have a multi-layered structure comprising low thermal expansion nonmagnetic layers, and magnetic layers. Material having a coefficient of thermal expansion smaller than that of a magnetoresistive film is selected as a material for the low thermal expansion nonmagnetic layers of the shield layer.
    Type: Application
    Filed: May 29, 2007
    Publication date: December 27, 2007
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Katsuro Watanabe, Katsumi Hoshino, Masafumi Mochizuki
  • Publication number: 20070253105
    Abstract: Embodiments in accordance with the present invention provide a thin film magnetic head for preventing a short-circuit failure during formation of a track portion or a stripe-height portion and improving a yield. In one embodiment, a stripe-height direction is first formed, and then a track-width direction is formed. A third insulating film having a smoothly shaped wall surface is formed on a first insulating film during stripe-height formation. During formation of the third insulating film, an optimized lift-off pattern is used to smooth an edge shape.
    Type: Application
    Filed: April 10, 2007
    Publication date: November 1, 2007
    Applicant: Hitachi Global Storage Technologies Netherlands, B.V.
    Inventors: Nubuo Yoshida, Katsuro Watanabe, Takayoshi Ohtsu
  • Patent number: 7280321
    Abstract: A magnetoresistive head of a type including a magnetoresistive film arranged between a lower shield layer and an upper shield layer, wherein the lower shield layer has a non-magnetic layer adjacent to it and the lower shield layer and the upper shield layer are formed such that their separation at at least part of a boundary between the lower shield layer and the upper shield layer is larger than their separation in a vicinity of the magnetoresistive film, and an insulating film is arranged between the lower shield layer and the upper shield layer, wherein the lower shield layer and the non-magnetic layer adjacent thereto are formed such that they differ in height and there exists a difference in level at their boundary.
    Type: Grant
    Filed: August 10, 2006
    Date of Patent: October 9, 2007
    Assignee: Hitachi Global Storage Technologies Japan, Ltd.
    Inventors: Katsuro Watanabe, Kikuo Kusukawa, Kenichi Meguro
  • Patent number: 7274542
    Abstract: A magnetic sensor includes a spacer having at least a nonmagnetic metal layer inserted between the upper shield layer and the longitudinal bias layers or between the upper shield layer and the longitudinal bias layers plus the magnetoresistive film, the shortest distance between the longitudinal bias layers and the free layer of the magnetoresistive film is set smaller than the shortest distance between the longitudinal bias layers and the upper shield layer, and this arrangement ensures that the amount of magnetic flux entering the magnetoresistive film from the longitudinal bias layers is larger than that absorbed by the upper shield layer, thus realizing a magnetic sensor whose Barkhausen noise is suppressed.
    Type: Grant
    Filed: February 5, 2003
    Date of Patent: September 25, 2007
    Assignee: Hitachi Global Storage Technologies Japan, Ltd.
    Inventors: Taku Shintani, Katsuro Watanabe, Masahiko Hatatani, Kikuo Kusukawa
  • Publication number: 20070206333
    Abstract: Embodiments in accordance with the present invention reduce the influence of etching damage at junction edge of a magnetoresistive film in the sensor height direction, lower the deterioration of dielectric breakdown voltage between an upper magnetic shield layer and a lower magnetic shield layer and instability of reproducing property resulting from shield process, and maintain electrostatic capacity to a small value in a CPP magnetoresistive head. In an embodiment of a magnetoresistive head of the present invention, length in the sensor height direction of bottom surface of a pinning layer is longer than the length in the sensor height direction of bottom surface of a first ferromagnetic layer.
    Type: Application
    Filed: February 13, 2007
    Publication date: September 6, 2007
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Katsuro Watanabe, Taku Shintani, Kazuhiro Ueda, Masahiro Osugi
  • Publication number: 20070030592
    Abstract: This invention provides a high-output magnetic head with a high yield, which is capable of minimizing sense current leak or noise caused by a shift of the magnetic wall of an upper shield layer. In one embodiment, the magnetic head is fabricated so that the height of the upper surface of the refill film along the sensor height direction is the same as that of the magnetoresistance layer in a portion where the refill film along the sensor height direction comes in contact with the magnetoresistance layer and the distance from the upper surface of the refill film along the sensor height direction to the upper surface of the lower shield layer gradually increases in a region from the portion where the refill film along the sensor height direction comes in contact with the magnetoresistance layer to a point at a certain distance away from the portion.
    Type: Application
    Filed: July 24, 2006
    Publication date: February 8, 2007
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Taku Shintani, Katsuro Watanabe, Nobuo Yoshida, Hisako Takei
  • Patent number: 7154713
    Abstract: A high output, magnetoresistive head with a CPP structure is disclosed which reduces or prevents deformation near the air bearing surface of the read element portion layer at the time of air bearing surface processing. In the CPP structure magnetoresistive head, the deformation near the air bearing surface as a result of mechanical polishing during the air bearing surface processing can be reduced by forming deformation prevention layers having a higher shear modulus than the first ferromagnetic layer, and a second ferromagnetic layer between a magnetoresistive film and at least one of a lower shield layer and an upper shield layer.
    Type: Grant
    Filed: January 3, 2006
    Date of Patent: December 26, 2006
    Assignee: Hitachi Global Storage Technologies Japan, Ltd.
    Inventors: Katsuro Watanabe, Kikuo Kusukawa, Taku Shintani, Kenichi Meguro
  • Publication number: 20060274457
    Abstract: A magnetoresistive head of a type including a magnetoresistive film arranged between a lower shield layer and an upper shield layer, wherein the lower shield layer has a non-magnetic layer adjacent to it and the lower shield layer and the upper shield layer are formed such that their separation at at least part of a boundary between the lower shield layer and the upper shield layer is larger than their separation in a vicinity of the magnetoresistive film, and an insulating film is arranged between the lower shield layer and the upper shield layer, wherein the lower shield layer and the non-magnetic layer adjacent thereto are formed such that they differ in height and there exists a difference in level at their boundary.
    Type: Application
    Filed: August 10, 2006
    Publication date: December 7, 2006
    Inventors: Katsuro Watanabe, Kikuo Kusukawa, Kenichi Meguro
  • Patent number: 7089648
    Abstract: There is provided a magnetoresistive head which can realize high sensitivity and low noise even when the reading track is being reduced. Longitudinal biasing is performed to a ferromagnetic free layer whose magnetization is rotated according to an external magnetic field by providing unidirectional magnetic anisotropy by exchange coupling to an antiferromagnetic layer. A hard magnetic film is arranged at the edge of a magnetoresistive film to reduce an effective reading track width.
    Type: Grant
    Filed: July 23, 2004
    Date of Patent: August 15, 2006
    Assignee: Hitachi, Ltd.
    Inventors: Kenichi Meguro, Hisashi Kimura, Katsuro Watanabe
  • Patent number: 7092217
    Abstract: A magnetoresistive head of CPP structure in which an insulating protective film 20 covers at least part of the boundary between the lower shield layer 10 and the non-magnetic film 11 adjacent thereto so as to reduce the area of the lower shield layer which is exposed on the surface of the substrate when the magnetoresistive film is patterned. This construction minimizes damage that occurs when the magnetoresistive film is patterned and also reduces the fraction defective due to current leakage across the upper and lower shields.
    Type: Grant
    Filed: July 23, 2002
    Date of Patent: August 15, 2006
    Assignee: Hitachi Global Storage Technologies Japan, Ltd.
    Inventors: Katsuro Watanabe, Kikuo Kusukawa, Kenichi Meguro
  • Publication number: 20060132983
    Abstract: A high output magneto-resistive sensor is provided by suppressing leftover resist mask after lift-off and generation of a fence, and by making it easy to remove the redepositions deposited on the side wall in the track width direction or on the side wall in the sensor height direction of the magnetoresistive film. As a means to solve a fence and lift-off leftover of a resist in a process for forming a track and a process for forming a sensor height, a stopper layer is provided on the magnetoresistive film and the stopper layer on the refill film, and performing lift-off by CMP. By using a metallic material which has a small CMP polishing rate for at least the first stopper layer, the magnetoresistive film and the first stopper layer can be etched simultaneously and a pattern formed. As a result, decrease of the height of the resist mask by RIE can be suppressed and lift-off leftover can be prevented.
    Type: Application
    Filed: November 29, 2005
    Publication date: June 22, 2006
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Masahiro Osugi, Taku Shintani, Katsuro Watanabe, Nobuo Yoshida
  • Publication number: 20060109592
    Abstract: A high output, magnetoresistive head with a CPP structure is disclosed which reduces or prevents deformation near the air bearing surface of the read element portion layer at the time of air bearing surface processing. In the CPP structure magnetoresistive head, the deformation near the air bearing surface as a result of mechanical polishing during the air bearing surface processing can be reduced by forming deformation prevention layers having a higher shear modulus than the first ferromagnetic layer, and a second ferromagnetic layer between a magnetoresistive film and at least one of a lower shield layer and an upper shield layer.
    Type: Application
    Filed: January 3, 2006
    Publication date: May 25, 2006
    Inventors: Katsuro Watanabe, Kikuo Kusukawa, Taku Shintani, Kenichi Meguro
  • Patent number: 7031119
    Abstract: A high output, magnetoresistive head with a CPP structure is disclosed which reduces or prevents deformation near the air bearing surface of the read element portion layer at the time of air bearing surface processing. In the CPP structure magnetoresistive head, the deformation near the air bearing surface as a result of mechanical polishing during the air bearing surface processing can be reduced by forming deformation prevention layers having a higher shear modulus than a first ferromagnetic layer, and a second ferromagnetic layer between a magnetoresistive film and at least one of a lower shield layer and an upper shield layer.
    Type: Grant
    Filed: February 21, 2003
    Date of Patent: April 18, 2006
    Assignee: Hitachi, Ltd.
    Inventors: Katsuro Watanabe, Kikuo Kusukawa, Taku Shintani, Kenichi Meguro
  • Patent number: 6999270
    Abstract: The CPP structure magnetoresistive head has a structure such that a first lead line is electrically connected to a lead contact portion attached to a lower shield layer the width of which is either equal to or shorter than the maximum length of the lower shield layer in the track direction, or the height of which is either equal to or shorter than the maximum length of the lower shield layer in the stripe height direction. With the structures above, it is possible to prevent that a bump is generated on the upper shield layer by the first lead line, and that a magnetic domain is formed by the bump, which is a cause of noise generation. Further, it is possible to avoid overlapping between the lead line and the upper shield layer.
    Type: Grant
    Filed: November 4, 2003
    Date of Patent: February 14, 2006
    Assignee: Hitachi, Ltd.
    Inventors: Katsuro Watanabe, Takayoshi Ohtsu, Kouji Kataoka, Nobuo Yoshida, Kikuo Kusukawa
  • Publication number: 20060018055
    Abstract: In a side shield structure employed to narrow the effective track, a noise caused by the side shield structure can be reduced. In one embodiment, the side shield is inclined with respect to the film plane to suppress the generation of a magnetic pole in the end portion of the side shield. To this end, the side face of a device is inclined at a desired angle. Further, a reproduction device is formed at two or more angles ?1 and ?2 to improve the track width accuracy.
    Type: Application
    Filed: June 24, 2005
    Publication date: January 26, 2006
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Chiseki Haginoya, Masahiko Hatatani, Chiaki Ishikawa, Kenichi Meguro, Kazuhiro Nakamoto, Katsuro Watanabe
  • Publication number: 20060007603
    Abstract: Embodiments of the invention provide a high-output magnetic reading head by making it easy to remove a re-deposited substance that deposits on the side wall surface in the track width direction or the side wall surface in the sensor height direction of a magneto-resistance film in a fabrication process of the magnetic reading head. In one embodiment, a refill film that is fabricated first of a refill film along track width direction or a refill film along sensor height direction is fabricated such that a layer in contact with the magneto-resistance film is formed of a material that is slow in etching rate but possible to minimize deterioration of characteristics due to thermal treatment and a layer(s) other than the layer in contact with the magneto-resistance film is formed of a material(s) that is fast in etching rate.
    Type: Application
    Filed: July 8, 2005
    Publication date: January 12, 2006
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Kenichi Meguro, Taku Shintani, Katsuro Watanabe, Nobuo Yoshida