Patents by Inventor Mohamad T. Krounbi

Mohamad T. Krounbi 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).

  • Patent number: 8104166
    Abstract: A method is provided for fabricating a read element with leads that overlay a top surface of a sensor of the read element. The method includes forming a mask over a sensor layer, then using the mask to define the sensor from the sensor layer. The mask is then narrowed and a lead layer is formed that overlays both ends of the top surface of the sensor without covering a center portion of the top surface.
    Type: Grant
    Filed: December 19, 2003
    Date of Patent: January 31, 2012
    Assignee: Western Digital (Fremont), LLC
    Inventors: Jinqiu Zhang, Ming Zhao, Mohamad T. Krounbi, Henry Yuan, Lien-Chang Wang
  • Patent number: 7882618
    Abstract: Methods of fabricating magnetic read heads are provided which reduce the width of the scratch exposure region of a read head. During normal fabrication processes, a read head is formed with a first shield, a read element formed on the first shield, and hard bias layers formed on either side of the read element. The width of the read elements and the hard bias layers define an initial scratch exposure region. According to embodiments herein, a mask structure is formed to protect the read element and first portions of the hard bias layers proximate to the read element. A removal process is then performed to remove second portions of the hard bias layers that are not protected by the mask structure, which defines a final scratch exposure region that is smaller than the initial scratch exposure region.
    Type: Grant
    Filed: December 16, 2007
    Date of Patent: February 8, 2011
    Assignee: Hitachi Global Storage Technologies Netherlands, B.V.
    Inventors: David P. Druist, Mohamad T. Krounbi, David J. Seagle
  • Patent number: 7691434
    Abstract: A method of fabricating a bias structure of a magnetoresistive read head for a magnetoresistive sensor stack formed on a substrate includes forming an underlayer and forming a bias layer over the underlayer. The method further includes forming a dusting layer directly below at least one of the underlayer or the bias layer and between the bias layer and the magnetoresistive sensor stack. The dusting layer includes discontinuous, nano-sized islands.
    Type: Grant
    Filed: January 9, 2008
    Date of Patent: April 6, 2010
    Assignee: Western Digital (Fremont), LLC
    Inventors: Wei Zhang, Yingjian Chen, Satoru Araki, Mohamad T. Krounbi
  • Patent number: 7639457
    Abstract: A magnetic sensor is disclosed comprising an antiferromagnetic layer; a first ferromagnetic layer disposed over the antiferromagnetic layer, the first ferromagnetic layer having a magnetization that is pinned by the antiferromagnetic layer; a second ferromagnetic layer disposed over the first ferromagnetic layer, the second ferromagnetic layer having a magnetization that rotates due to an applied magnetic field; a third ferromagnetic layer disposed adjacent to an end of the second ferromagnetic layer, the third ferromagnetic layer having a primarily in-plane magnetization providing a magnetic field to stabilize the end of the second ferromagnetic layer; an amorphous, metallic, nonmagnetic underlayer disposed adjacent to the antiferromagnetic layer; and a crystalline seed layer disposed between the underlayer and the third ferromagnetic layer, the seed layer having a crystalline structure that promotes the in-plane magnetization of the third ferromagnetic layer.
    Type: Grant
    Filed: February 27, 2004
    Date of Patent: December 29, 2009
    Assignee: Western Digital (Fremont), LLC
    Inventors: Yingjian Chen, Wei Zhang, Jinqiu Zhang, Haifeng Wang, Satoru Araki, Mohamad T. Krounbi
  • Publication number: 20090151151
    Abstract: Methods of fabricating magnetic read heads are provided which reduce the width of the scratch exposure region of a read head. During normal fabrication processes, a read head is formed with a first shield, a read element formed on the first shield, and hard bias layers formed on either side of the read element. The width of the read elements and the hard bias layers define an initial scratch exposure region. According to embodiments herein, a mask structure is formed to protect the read element and first portions of the hard bias layers proximate to the read element. A removal process is then performed to remove second portions of the hard bias layers that are not protected by the mask structure, which defines a final scratch exposure region that is smaller than the initial scratch exposure region.
    Type: Application
    Filed: December 16, 2007
    Publication date: June 18, 2009
    Inventors: David P. Druist, Mohamad T. Krounbi, David J. Seagle
  • Patent number: 7522379
    Abstract: A head including a write element for writing data to a magnetic media, and methods for its production are provided. A write element of the invention includes one or more of a recessed first pole, a heat sink layer, and a shortened yoke length. A method of the invention provides forming an anti-reflective layer before forming a mask layer. During photolithography the anti-reflective layer suppresses undesirable reflections off of features, such as vertical sidewalls, that otherwise limit how closely to such features portions of the mask layer can be formed.
    Type: Grant
    Filed: July 30, 2004
    Date of Patent: April 21, 2009
    Assignee: Western Digital (Fremont), LLC
    Inventors: Mohamad T. Krounbi, Yining Hu, Ming Zhao, Kenneth Kung, Mark D. Thomas, Kroum S. Stoev, Francis H. Liu, Marcos M. Lederman
  • Patent number: 7386933
    Abstract: A method for fabricating a magnetic recording head writer. The writer includes a bottom magnetic pole and a write gap formed over the bottom pole and a coil trench formed in the bottom pole. A top magnetic pole is provided as two layers with the first layer including front and back tips with spaced apart walls positioned adjacent the trench bottom defining trench sides. A pole cover layer is included that is made up of a thin layer of insulating material deposited to cover sides and bottom of the coil trench. A bottom coil is formed on the pole cover layer in the bottom of the coil trench and coil insulation is provided between coil elements and adjacent trench walls and covemg the coil. A top coil with insulation is formed over the planarized bottom coil insulation and the top pole second layer is formed over the top coil.
    Type: Grant
    Filed: December 6, 2005
    Date of Patent: June 17, 2008
    Assignee: Western Digital (Fremont), LLC
    Inventors: Mohamad T. Krounbi, Ming Zhao, Yining Hu, Jim Watterston
  • Patent number: 7379269
    Abstract: A head including a write element for writing data to a magnetic media, and methods for its production are provided. A write element of the invention includes one or more of a recessed first pole, a heat sink layer, and a shortened yoke length. A method of the invention provides forming an anti-reflective layer before forming a mask layer. During photolithography the anti-reflective layer suppresses undesirable reflections off of features, such as vertical sidewalls, that otherwise limit how closely to such features portions of the mask layer can be formed.
    Type: Grant
    Filed: July 30, 2004
    Date of Patent: May 27, 2008
    Assignee: Western Digital (Fremont), LLC
    Inventors: Mohamad T. Krounbi, Li He, Ming Zhao, Yining Hu
  • Patent number: 7342752
    Abstract: A magnetoresistive read head includes a magnetoresistive sensor and a bias structure adjacent to the magnetoresistive sensor. The bias structure provides a magnetostatic bias field for the magnetoresistive sensor. The bias structure includes an underlayer, a bias layer over the underlayer, and at least one dusting layer directly below at least one of the underlayer or the bias layer.
    Type: Grant
    Filed: January 31, 2004
    Date of Patent: March 11, 2008
    Assignee: Western Digital (Fremont), LLC
    Inventors: Wei Zhang, Yingjian Chen, Satoru Araki, Mohamad T Krounbi
  • Patent number: 7333295
    Abstract: A method and system for plating CoNiFe is disclosed. The method and system include providing a plating solution including hydroxymethyl-p-tolylsulfone and plating the CoNiFe film on a substrate in the plating solution. The plating solution is configured to provide a CoNiFe film having a high saturation magnetic flux density and having a composition of 50-70 weight percent of Fe and 3-8 weight percent of Ni. In another aspect, the method and system include plating at least a portion of a first and/or second pole of a write head using the plating solution including hydroxymethyl-p-tolylsulfone and configured to plate the CoNiFe film having a high saturation magnetic flux density and a composition of 50-70 weight percent of Fe and 3-8 weight percent of Ni.
    Type: Grant
    Filed: March 31, 2004
    Date of Patent: February 19, 2008
    Assignee: Western Digital (Fremont), LLC
    Inventors: Jose A. Medina, Thomas E. Dinan, Tiffany Yun Wen Jiang, Mohamad T. Krounbi
  • Patent number: 7286329
    Abstract: A magnetic sensor is disclosed having a shallow contiguous junction. Such a sensor is can greatly increase yield for mass-produced heads, especially for large wafers. The magnetic bias layers can be aligned with a free layer of the sensor, improving performance. Milling may be terminated prior to penetration of an antiferromagnetic layer, so that for example the antiferromagnetic layer may extend significantly beyond the free and pinned layers of the sensor.
    Type: Grant
    Filed: February 27, 2004
    Date of Patent: October 23, 2007
    Assignee: Western Digital (Fremont), LLC
    Inventors: Yingjian Chen, Wei Zhang, Mohamad T. Krounbi, Satoru Araki, Jinqiu Zhang
  • Patent number: 7283327
    Abstract: A magnetic write head includes a magnetic yoke having a first pole and a second pole. The first pole and the second pole each terminate at an air bearing surface. The first pole is magnetically coupled to the second pole in a backgap region. The magnetic write head further includes a electrically conductive write coil magnetically coupled to the magnetic yoke. The magnetic write head further includes a resistive heater coil having a first coil turn and a second coil turn. The heater coil is electrically isolated from the write coil. At least a portion of the first coil turn is between the first pole and the second pole and between the air bearing surface and the backgap region. At least a portion of the second coil turn is between the first pole and the second pole and between the air bearing surface and the backgap region. The portion of the first coil turn overlaps the portion of the second coil turn.
    Type: Grant
    Filed: June 13, 2006
    Date of Patent: October 16, 2007
    Assignee: Western Digital (Fremont), LLC
    Inventors: Francis H. Liu, Kroum S. Stoev, Mohamad T. Krounbi
  • Patent number: 7092195
    Abstract: A method adjusts a flying-height distance between a magnetic write head and a magnetic medium. The method includes positioning the write head in a location spaced from the magnetic medium by the flying-height distance. The write head includes a magnetic yoke and a proximal region in proximity to the magnetic medium. The write head further includes a resistive heater and at least a portion of the resistive heater is within the magnetic yoke and is in proximity to the proximal region. The resistive heater is configured to heat the proximal region. The proximal region has a coefficient of thermal expansion. The proximal region is configured to expand and to contract in response to a temperature of the proximal region. The method further includes flowing an electric current through the resistive heater. The method further includes controlling the electric current to adjust the temperature of the proximal region to selectively expand and contract the proximal region and thereby control the flying-height distance.
    Type: Grant
    Filed: May 28, 2004
    Date of Patent: August 15, 2006
    Assignee: Western Digital (Fremont), Inc.
    Inventors: Francis H. Liu, Kroum S. Stoev, Mohamad T. Krounbi
  • Patent number: 7006327
    Abstract: A writer for magnetic recording heads. The writer includes a bottom magnetic pole and a write gap formed over the bottom pole and a coil trench formed in the bottom pole. A top magnetic pole is provided as two layers with the first layer including front and back tips with spaced apart walls positioned adjacent the trench bottom defining trench sides. A pole cover layer is included that is made up of a thin layer of insulating material deposited to cover the sides and bottom of the coil trench. A bottom coil is formed on the pole cover layer in the bottom of the coil trench and coil insulation is provided between the coil elements and adjacent the trench walls and covering the coil. A top coil with insulation is formed over the planarized bottom coil insulation and the top pole second layer is formed over the top coil.
    Type: Grant
    Filed: February 27, 2003
    Date of Patent: February 28, 2006
    Assignee: Western Digital (Fremont), Inc.
    Inventors: Mohamad T. Krounbi, Ming Zhao, Yining Hu, Jim Watterston
  • Patent number: 6975486
    Abstract: A writer for high frequency, data storage heads. The writer includes a first magnetic pole upon which a write gap pedestal is formed with an upper pedestal layer of high moment material with a planar upper surface. An electrical coil is formed on the first magnetic pole. A write gap layer is deposited on the upper surface of the upper pedestal layer. The writer includes a second magnetic pole disposed above the first magnetic pole with a magnetic, flat, top pole layer. The second magnetic pole includes a bottom shaper fabricated from high moment material positioned between the coil and the top pole layer. An insulation insert separates the bottom shaper from the upper pedestal layer. The second magnetic pole includes a thin dielectric lamination layer that separates the top pole layer from the bottom shaper to disrupt the path of eddy current in the second magnetic pole.
    Type: Grant
    Filed: August 6, 2002
    Date of Patent: December 13, 2005
    Assignee: Western Digital (Fremont), Inc.
    Inventors: Yingjian Chen, Xiaozhong Dang, Mohamad T. Krounbi, George V. Kelley
  • Publication number: 20040169958
    Abstract: A writer for magnetic recording heads. The writer includes a bottom magnetic pole and a write gap formed over the bottom pole and a coil trench formed in the bottom pole. A top magnetic pole is provided as two layers with the first layer including front and back tips with spaced apart walls positioned adjacent the trench bottom defining trench sides. A pole cover layer is included that is made up of a thin layer of insulating material deposited to cover the sides and bottom of the coil trench. A bottom coil is formed on the pole cover layer in the bottom of the coil trench and coil insulation is provided between the coil elements and adjacent the trench walls and coverng the coil. A top coil with insulation is formed over the planarized bottom coil insulation and the top pole second layer is formed over the top coil.
    Type: Application
    Filed: February 27, 2003
    Publication date: September 2, 2004
    Inventors: Mohamad T. Krounbi, Ming Zhao, Yining Hu, Jim Watterston
  • Patent number: 6778358
    Abstract: In one aspect, a laminated structure including a first plurality of layers containing primarily-iron FeCoN interleaved with a second plurality of layers containing primarily iron FeNi is disclosed. The structure has an easy axis of magnetization and a hard axis of magnetization, has a magnetic saturation of at least about twenty-three-thousand Gauss, and has a magnetic coercivity measured substantially along its hard axis of magnetization that is less than two Oersted. Additional elements can be added in minority concentrations to form primarily-iron FeCoN layers with increased resistivity. The laminated structure has applicability in various fields in which high saturation magnetization, magnetically soft materials are advantageous, particularly for inductive heads.
    Type: Grant
    Filed: May 1, 2002
    Date of Patent: August 17, 2004
    Assignee: Western Digital (Fremont), Inc.
    Inventors: Hai Jiang, Yingjian Chen, Xiaozhong Dang, Mohamad T. Krounbi
  • Patent number: 6751055
    Abstract: An inductive transducer has inorganic nonferromagnetic material disposed in an apex region adjacent to a submicron nonferromagnetic gap in a magnetic core. The inorganic nonferromagnetic material has a much lower coefficient of thermal expansion than that of hardbaked photoresist, reducing pole tip protrusion even if other insulation surrounding the coil sections within the core is made of hardbaked photoresist. Alternatively, the entire insulation surrounding the coil sections within the core, in addition to the apex region, can be formed of inorganic nonferromagnetic material, further reducing pole tip protrusion. The transducer has SiO2 rather than alumina in an undercoat layer joining the wafer substrate and the thin film layers of the transducer. SiO2 may also replace alumina in other areas, such as a piggyback layer joining the inductive transducer with a magnetoresistive transducer.
    Type: Grant
    Filed: January 8, 2002
    Date of Patent: June 15, 2004
    Assignee: Western Digital (Fremont), Inc.
    Inventors: Arshad Alfoqaha, Mohamad T. Krounbi, Sandrawattie Sankar, David J. Seagle, Kenneth R. Young
  • Patent number: 6693760
    Abstract: A preamplifier circuit is disclosed comprising a data input for receiving write data, a read signal output for outputting an amplified read signal, a read signal input for receiving a read signal from a read element, and a write signal output for supplying a write signal to a write element. The preamplifier circuit further comprises a first amplifier circuit, responsive to the write data, for generating the write signal supplied to the write element, and a second amplifier circuit for amplifying the read signal from the read element to generate the amplified read signal output via the read signal output. A head control circuit, responsive to head select data, simultaneously enables the first and second amplifier circuits to perform a simultaneous read and write operation.
    Type: Grant
    Filed: March 31, 2000
    Date of Patent: February 17, 2004
    Assignee: Western Digital Technologies, Inc.
    Inventors: Mohamad T. Krounbi, John Cuda, Jack M. Chue, Robert Leslie Cloke, David Price Turner, Gary L. Dunbar
  • Publication number: 20040027716
    Abstract: A writer for high frequency, data storage heads. The writer includes a first magnetic pole upon which a write gap pedestal is formed with an upper pedestal layer of high moment material with a planar upper surface. An electrical coil is formed on the first magnetic pole. A write gap layer is deposited on the upper surface of the upper pedestal layer. The writer includes a second magnetic pole disposed above the first magnetic pole with a magnetic, flat, top pole layer. The second magnetic pole includes a bottom shaper fabricated from high moment material positioned between the coil and the top pole layer. An insulation insert separates the bottom shaper from the upper pedestal layer. The second magnetic pole includes a thin dielectric lamination layer that separates the top pole layer from the bottom shaper to disrupt the path of eddy current in the second magnetic pole.
    Type: Application
    Filed: August 6, 2002
    Publication date: February 12, 2004
    Inventors: Yingjian Chen, Xiaozhong Dang, Mohamad T. Krounbi, George V. Kelley