Patents by Inventor Murali Ramasubramanian

Murali Ramasubramanian 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: 20070068801
    Abstract: A system for plating according to one embodiment includes a plating cell containing plating solution; an anode in contact with the plating solution; a cathode in contact with the plating solution; and a hydrogen electrode in contact with the plating solution.
    Type: Application
    Filed: November 16, 2006
    Publication date: March 29, 2007
    Inventors: Wolfgang Diel, Richard Peekema, Murali Ramasubramanian
  • Patent number: 7156972
    Abstract: A system and method for reducing ferric ion content in a plating solution by exposing hydrogen to an electrode in a plating solution for reducing a ferric ion content in the plating solution.
    Type: Grant
    Filed: April 30, 2003
    Date of Patent: January 2, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Wolfgang Diel, Richard M. Peekema, Murali Ramasubramanian
  • Publication number: 20060191784
    Abstract: Improved methods and systems for electroplating wafers are described herein. The method includes the acts of introducing a wafer which is coupled to an electrode into an electroplating cell having a counter electrode; maintaining a flow of a plating solution through the cell for electroplating the wafer; removing the wafer from the cell; stopping the flow of the plating solution through the cell; maintaining a volume of plating solution within the cell sufficient to keep the counter electrode submerged during stoppage of flow; removing the plating solution within the cell; and repeating the above steps for a subsequent wafer. By stopping the flow of plating solution after completion of plating one or more wafers, a consumption rate of additives enhancing electroplating properties is reduced, a production rate of breakdown products produced during electroplating is reduced, plating solution useable life is increased, and a need for plating solution analysis is reduced.
    Type: Application
    Filed: February 28, 2005
    Publication date: August 31, 2006
    Inventors: Robert Hitzfeld, Jennifer Loo, Murali Ramasubramanian
  • Patent number: 7075750
    Abstract: An apparatus for patterning a self-aligned coil using a damascene process is disclosed. Coil pockets are formed in a first insulation layer disposed over a first pole layer. A barrier/seed layer is deposited along walls of the coil pockets in the insulation layer. Copper is formed in the coil pockets and over the insulation layer. The copper is planarized down to the insulation layer. The self-aligned coil process packs more copper into the same coil pocket and relaxes the coil alignment tolerance. Protrusions are prevented because of the more efficient and uniform spacing of the coil to reduce heat buildup in the head during a write.
    Type: Grant
    Filed: August 29, 2003
    Date of Patent: July 11, 2006
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Daniel Wayne Bedell, Quang Le, Edward Hin Pong Lee, Son Van Nguyen, Vladimir Nikitin, Murali Ramasubramanian
  • Publication number: 20060070232
    Abstract: A method for reducing plated pole height loss in the formation of a write pole for a magnetic write head is disclosed. The method includes forming a conductive layer on a thin film substrate, forming a photoresist layer on the conductive layer and forming a trench in the photoresist layer. A thick seed layer is then placed on the trench and on the photoresist layer surface using a collimator. Moreover, the process includes plating while applying a voltage to the thin film substrate where the electrically isolated seed layer is removed and the trench is filled with plating material, removing the photoresist layer, and removing the exposed portions of the conductive layer on the thin film substrate.
    Type: Application
    Filed: September 30, 2004
    Publication date: April 6, 2006
    Inventors: Daniel Bedell, Jennifer Loo, Aron Pentek, Murali Ramasubramanian
  • Patent number: 7022248
    Abstract: A method for patterning a self-aligned coil using a damascene process is disclosed. Coil pockets are formed in a first insulation layer disposed over a first pole layer. A barrier/seed layer is deposited along walls of the coil pockets in the insulation layer. Copper is formed in the coil pockets and over the insulation layer. The copper is planarized down to the insulation layer. The self-aligned coil process packs more copper into the same coil pocket and relaxes the coil alignment tolerance. Protrusions are prevented because of the more efficient and uniform spacing of the coil to reduce heat buildup in the head during a write.
    Type: Grant
    Filed: August 29, 2003
    Date of Patent: April 4, 2006
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Daniel Wayne Bedell, Quang Le, Edward Hin Pong Lee, Son Van Nguyen, Vladimir Nikitin, Murali Ramasubramanian
  • Patent number: 7001499
    Abstract: A process for electroplating and annealing thin-films of nickel-iron alloys having from 63% to 81% iron content by weight to produce pole pieces having saturation flux density (BS) in the range from 1.9 to 2.3 T (19 to 23 kG) with acceptable magnetic anisotropy and magnetostriction and a coercivity (HC) no higher than 160 A/m (2 Oe). The desired alloy layer properties, including small crystal size and minimal impurity inclusions, can be produced by including higher relative levels of Fe++ ions in the electroplating bath while holding the bath at a lower temperature while plating from a suitable seed layer. The resulting alloy layer adopts a small crystal size (BCC) without significant inclusion of impurities, which advantageously permits annealing to an acceptable HC while retaining the high BS desired.
    Type: Grant
    Filed: January 18, 2002
    Date of Patent: February 21, 2006
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Mike Ming Yu Chen, Thomas Edward Dinan, April Hixson-Goldsmith, Murali Ramasubramanian, Neil Leslie Robertson
  • Publication number: 20060002022
    Abstract: A first magnetic shield layer of the read head sensor is deposited upon a slider substrate surface. A patterned photoresist is then photolithographically fabricated upon the first magnetic shield layer with openings that are formed alongside the location at which the read sensor will be fabricated. An ion milling step is performed to create pockets within the surface of the magnetic shield layer at the location of the openings in the photoresist layer. The photoresist layer is then removed, and a fill layer is deposited across the surface of the magnetic shield layer in a depth greater than the depth of the pocket. Thereafter, a polishing step is conducted to remove portions of the fill layer down to the surface of the magnetic shield layer. A G1 insulation layer is deposited and a magnetic head sensor element is then fabricated upon the insulation layer.
    Type: Application
    Filed: June 30, 2004
    Publication date: January 5, 2006
    Inventors: Michael Feldbaum, John Kim, Murali Ramasubramanian, Howard Zolla
  • Publication number: 20050125990
    Abstract: An improved damascene method of forming a write coil of a magnetic head includes forming a hard mask layer over an insulator layer; forming a photoresist layer over the hard mask layer; performing an image patterning process to produce a write coil pattern in the photoresist layer; etching to remove portions of the hard mask layer in accordance with the write coil pattern; etching to remove portions of the insulator layer in accordance with the write coil pattern; etching to remove the remaining portion of the etched hard mask layer; electroplating a material comprising copper (Cu) within the etched portion of the insulator material; and performing a chemical-mechanical polishing (CMP) process over the resulting structure. By removing the remainder of the hard mask material before the CMP, the quality of the CMP is improved.
    Type: Application
    Filed: December 12, 2003
    Publication date: June 16, 2005
    Inventors: Donald Allen, Richard Contreras, Michael Feldbaum, Murali Ramasubramanian
  • Publication number: 20050130078
    Abstract: Method of plating using a polymeric barrier layer including a polyphenolic polymer which has a repeating unit of the formula: wherein R1, R2, R3, R4, and R5 are individually hydrogen, a hydroxy group or an azo dye.
    Type: Application
    Filed: December 10, 2003
    Publication date: June 16, 2005
    Inventors: Daniel Bedell, Gregory Breyta, Tom Harris, April Hixson-Goldsmith, Murali Ramasubramanian, Alfred Renaldo, Benjamin Wang
  • Publication number: 20050045848
    Abstract: A method for patterning a self-aligned coil using a damascene process is disclosed. Coil pockets are formed in a first insulation layer disposed over a first pole layer. A barrier/seed layer is deposited along walls of the coil pockets in the insulation layer. Copper is formed in the coil pockets and over the insulation layer. The copper is planarized down to the insulation layer. The self-aligned coil process packs more copper into the same coil pocket and relaxes the coil alignment tolerance. Protrusions are prevented because of the more efficient and uniform spacing of the coil to reduce heat buildup in the head during a write.
    Type: Application
    Filed: August 29, 2003
    Publication date: March 3, 2005
    Inventors: Daniel Bedell, Quang Le, Edward Lee, Son Nguyen, Vladimir Nikitin, Murali Ramasubramanian
  • Publication number: 20050047014
    Abstract: An apparatus for patterning a self-aligned coil using a damascene process is disclosed. Coil pockets are formed in a first insulation layer disposed over a first pole layer. A barrier/seed layer is deposited along walls of the coil pockets in the insulation layer. Copper is formed in the coil pockets and over the insulation layer. The copper is planarized down to the insulation layer. The self-aligned coil process packs more copper into the same coil pocket and relaxes the coil alignment tolerance. Protrusions are prevented because of the more efficient and uniform spacing of the coil to reduce heat buildup in the head during a write.
    Type: Application
    Filed: August 29, 2003
    Publication date: March 3, 2005
    Inventors: Daniel Bedell, Quang Le, Edward Lee, Son Nguyen, Vladimir Nikitin, Murali Ramasubramanian
  • Publication number: 20040217007
    Abstract: A system and method for reducing ferric ion content in a plating solution by exposing hydrogen to an electrode in a plating solution for reducing a ferric ion content in the plating solution.
    Type: Application
    Filed: April 30, 2003
    Publication date: November 4, 2004
    Applicant: HITACHI GLOBAL STORAGE TECHNOLOGIES
    Inventors: Wolfgang Diel, Richard M. Peekema, Murali Ramasubramanian
  • Patent number: 6793961
    Abstract: A method for fabricating a soft ferromagnetic film structure with reduced edge stress anisotropy and enhanced magnetization switching speed. A soft ferromagnetic film structure is formed over an underlying structure. The soft ferromagnetic film structure has one or more edges exhibiting edge stress anisotropy. A non-ferromagnetic film structure is formed along the one or more edges to induce stress contributions therein that control the edge stress anisotropy.
    Type: Grant
    Filed: November 19, 2003
    Date of Patent: September 21, 2004
    Assignee: International Business Machines Corporation
    Inventors: Vladimir Nikitin, Jeffrey Gregory McCord, Murali Ramasubramanian
  • Publication number: 20040100729
    Abstract: A method for fabricating a soft ferromagnetic film structure with reduced edge stress anisotropy and enhanced magnetization switching speed. A soft ferromagnetic film structure is formed over an underlying structure. The soft ferromagnetic film structure has one or more edges exhibiting edge stress anisotropy. A non-ferromagnetic film structure is formed along the one or more edges to induce stress contributions therein that control the edge stress anisotropy.
    Type: Application
    Filed: November 19, 2003
    Publication date: May 27, 2004
    Inventors: Vladimir Nikitin, Jeffrey Gregory McCord, Murali Ramasubramanian
  • Publication number: 20040027715
    Abstract: A method for multi-layer electrodeposition in a single bath is also provided. A substrate is immersed in a bath. An electrodeposition operation is initiated for depositing a first layer of material on the substrate. The electrodeposition operation includes agitating the bath and applying current pulses. The electrodeposition operation is later altered for depositing a second layer of material on the first layer, where the second layer is of a different composition than the first layer. In the altered mode, the current density is changed for altering a composition of material deposited on the substrate, the duration and/or frequency of the current pulses are altered, and the bath is agitated at a different rate of agitation.
    Type: Application
    Filed: August 12, 2002
    Publication date: February 12, 2004
    Applicant: INTERNATIONAL BUSINESS MACHINES
    Inventors: April Dawn Hixson-Goldsmith, Matthew Walter Last, Murali Ramasubramanian, Rolf Schaefer
  • Patent number: 6678125
    Abstract: A method for fabricating a soft ferromagnetic film structure with reduced edge stress anisotropy and enhanced magnetization switching speed. A soft ferromagnetic film structure is formed over an underlying structure. The soft ferromagnetic film structure has one or more edges exhibiting edge stress anisotropy. A non-ferromagnetic film structure is formed along the one or more edges to induce stress contributions therein that control the edge stress anisotropy.
    Type: Grant
    Filed: January 11, 2002
    Date of Patent: January 13, 2004
    Assignee: International Business Machines Corporation
    Inventors: Vladimir Nikitin, Jeffrey Gregory McCord, Murali Ramasubramanian
  • Publication number: 20030133231
    Abstract: A method for fabricating a soft ferromagnetic film structure with reduced edge stress anisotropy and enhanced magnetization switching speed. A soft ferromagnetic film structure is formed over an underlying structure. The soft ferromagnetic film structure has one or more edges exhibiting edge stress anisotropy. A non-ferromagnetic film structure is formed along the one or more edges to induce stress contributions therein that control the edge stress anisotropy.
    Type: Application
    Filed: January 11, 2002
    Publication date: July 17, 2003
    Applicant: International Business Machines Corporation
    Inventors: Vladimir Nikitin, Jeffrey Gregory McCord, Murali Ramasubramanian