Patents by Inventor Wipul Pemsiri Jayasekara

Wipul Pemsiri Jayasekara 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: 20070266549
    Abstract: An improved method for the manufacture of magnetoresistive multilayer sensors is disclosed. The method is particularly advantageous for the production of magnetic tunnel junction (MTJ) sensors, which can be damaged at the air bearing surface by conventional lapping and ion milling. The disclosed process protects the ABS of the magnetoresistive sensor by depositing a diamond like carbon layer which remains in place through ion milling. The DLC layer is removed by oxidation subsequent to the formation of the ABS.
    Type: Application
    Filed: May 16, 2006
    Publication date: November 22, 2007
    Inventors: Hardayal Singh Gill, Wipul Pemsiri Jayasekara, Huey-Ming Tzeng, Xiao Z. Wu
  • Patent number: 7295401
    Abstract: A perpendicular write head is disclosed for writing information onto tracks. The write head includes a top pole and a return pole and side shields with laminated layers wherein said laminated layers have magnetization in a direction parallel to an air bearing surface (ABS) and perpendicular to the tracks.
    Type: Grant
    Filed: October 27, 2004
    Date of Patent: November 13, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Wipul Pemsiri Jayasekara, Hardayal Singh Gill
  • Patent number: 7281316
    Abstract: A magnetic structure, such as a pole tip, and method for forming the same includes forming a pole tip layer of magnetic material. A layer of polyimide precursor material is added above the pole tip layer and cured. A silicon-containing resist layer is added above the layer of polyimide precursor material and patterned. The resist layer is exposed to oxygen plasma for converting the resist into a glass-like material. Exposed portions of the cured polyimide precursor material are removed for exposing portions of the pole tip layer. The exposed portions of the pole tip layer are removed for forming a pole tip. Chemical mechanical polishing (CMP) can then be performed to remove any unwanted material remaining above the pole tip.
    Type: Grant
    Filed: June 30, 2004
    Date of Patent: October 16, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Richard Hsiao, Wipul Pemsiri Jayasekara, Jeffrey S. Lille
  • Patent number: 7270758
    Abstract: A method is presented for fabricating a read head having a read head sensor and a hard bias/lead layer which includes depositing a strip of sensor material in a sensor material region, and depositing strips of fast-milling dielectric material in first and second fast-milling dielectric material regions adjacent to the sensor material region. A protective layer and a layer of masking material is deposited on the strip of sensor material and the strips of fast-milling dielectric material to provide masked areas and exposed areas. A shaping source, such as an ion milling source, is provided which shapes the exposed areas. Hard bias/lead material is then deposited on the regions of sensor material and fast-milling dielectric material to form first and second leads and a cap on each of these regions. The cap of hard bias/lead material and the masking material is then removed from each of these regions.
    Type: Grant
    Filed: March 15, 2005
    Date of Patent: September 18, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands, B.V.
    Inventors: Shawn Marie Collier Hernandez, Wipul Pemsiri Jayasekara, Timothy J. Minvielle, Benjamin Lu chen Wang, Howard Gordon Zolla
  • Patent number: 7251103
    Abstract: A magnetic structure, such as a pole tip, and method for forming the same includes forming a pole tip layer of magnetic material. A layer of polyimide precursor material is added above the pole tip layer and cured. A silicon-containing resist layer is added above the layer of polyimide precursor material and patterned. The resist layer is exposed to oxygen plasma for converting the resist into a glass-like material. Exposed portions of the cured polyimide precursor material are removed for exposing portions of the pole tip layer. The exposed portions of the pole tip layer are removed for forming a pole tip. Chemical mechanical polishing (CMP) can then be performed to remove any unwanted material remaining above the pole tip.
    Type: Grant
    Filed: June 30, 2004
    Date of Patent: July 31, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Richard Hsiao, Wipul Pemsiri Jayasekara, Jeffrey S. Lille
  • Patent number: 7075094
    Abstract: A system for improving drift compensation for ion mill applications defines a reference step for purposes of time duration. The reference step is controlled by an end point detector and monitored for use with subsequent process steps. The time duration for a subsequent step is adjusted as a percentage of the reference step. A time scaling factor determines the actual duration of the subsequent step. Rather than directly using times of step duration, the system uses a percentage of the reference step for the latter step. The duration of the reference step varies depending on the tool drift. The overall duration is changed in the same proportion as the duration of the reference step, and thereby compensates for the influence of drift on the end product.
    Type: Grant
    Filed: August 30, 2004
    Date of Patent: July 11, 2006
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Michael Feldbaum, Hung-Chin Guthrie, Wipul Pemsiri Jayasekara, Aron Pentek
  • Patent number: 7005242
    Abstract: A read sensor and method of making the same using an etch-stop layer are disclosed. The method is particularly suitable in connection with techniques requiring the partial removal of the capping layer, such as exchange tab (ET) and lead overlay (LOL) techniques. Basically, a thin “etch-stop” layer is deposited over a top free layer of sensor materials. The etch-stop layer is made of a suitable material such as copper-oxide (CuO) or nickel-iron-chromium (NiFeCr). A tantalum (Ta) capping layer is then deposited over the etch-stop layer. When appropriate, top edge portions of the capping layer are exposed to a reactive ion etch (RIE) using a fluorine gas for removal. Advantageously, the etch-stop layer significantly reduces or eliminates damage to the free layer that would otherwise occur due to the fluorine gas RIE.
    Type: Grant
    Filed: March 22, 2002
    Date of Patent: February 28, 2006
    Assignee: International Business Machines Corporation
    Inventor: Wipul Pemsiri Jayasekara
  • Patent number: 6996894
    Abstract: Methods of making a read head with improved contiguous junctions are described. After sensor layer materials are deposited over a substrate, a lift-off mask is formed over the sensor layer materials in a central region which is surrounded by end regions. Ion milling is performed with use of the lift-off mask such that the sensor layer materials in the end regions are removed and those in the central region remain to form a read sensor. A high-angle ion mill (e.g. between 45–80 degrees) is then performed to remove redeposited material from side walls of the lift-off mask. Next, a reactive ion etch (RIE) is used to reduce the thickness and the width of the lift-off mask and to remove capping layer materials from the top edges of the read sensor. With the reduced-size lift-off mask in place, hard bias and lead layers are deposited adjacent the read sensor as well as over the mask.
    Type: Grant
    Filed: March 28, 2002
    Date of Patent: February 14, 2006
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Richard Hsiao, Wipul Pemsiri Jayasekara, Mustafa Pinarbasi, Patrick Rush Webb
  • Patent number: 6982042
    Abstract: A method for reducing noise in a lapping guide. Selected portions of a Giant magnetoresistive device wafer are masked, thereby defining masked and unmasked regions of the wafer in which the unmasked regions include lapping guides. The wafer is bombarded with ions such that a Giant magnetoresistive effect of the unmasked regions is reduced.
    Type: Grant
    Filed: February 28, 2003
    Date of Patent: January 3, 2006
    Assignee: Hitachi Global Storage Technologies Netherlands, B.V.
    Inventors: Mark A. Church, Wipul Pemsiri Jayasekara, Howard Gordon Zolla
  • Patent number: 6919280
    Abstract: During manufacture, a magnetoresistive sensor having a ferromagnetic free layer is commonly provided with a tantalum cap layer. The tantalum cap layer provides protection to the sensor during manufacture and then is typically removed after performing annealing. The removal of the tantalum cap with a fluorine reactive ion etch leaves low volatility tantalum/fluorine byproducts. The present invention provides a method of using an argon/hydrogen reactive ion etch to remove the tantalum/fluorine byproducts. The resulting sensor has far less damage resulting from the presence of the fluorine byproducts.
    Type: Grant
    Filed: October 15, 2002
    Date of Patent: July 19, 2005
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Richard Hsiao, Wipul Pemsiri Jayasekara, Son Van Nguyen, Sue Zhang
  • Publication number: 20040180608
    Abstract: A method for reducing noise in a lapping guide. Selected portions of a Giant magnetoresistive device wafer are masked, thereby defining masked and unmasked regions of the wafer in which the unmasked regions include lapping guides. The wafer is bombarded with ions such that a Giant magnetoresistive effect of the unmasked regions is reduced.
    Type: Application
    Filed: February 28, 2003
    Publication date: September 16, 2004
    Applicant: INTERNATIONAL BUSINESS MACHINES
    Inventors: Mark A. Church, Wipul Pemsiri Jayasekara, Howard Gordon Zolla
  • Publication number: 20040069746
    Abstract: During manufacture, a magnetoresistive sensor having a ferromagnetic free layer is commonly provided with a tantalum cap layer. The tantalum cap layer provides protection to the sensor during manufacture and then is typically removed after performing annealing. The removal of the tantalum cap with a fluorine reactive ion etch leaves low volatility tantalum/fluorine byproducts. The present invention provides a method of using an argon/hydrogen reactive ion etch to remove the tantalum/fluorine byproducts. The resulting sensor has far less damage resulting from the presence of the fluorine byproducts.
    Type: Application
    Filed: October 15, 2002
    Publication date: April 15, 2004
    Inventors: Richard Hsiao, Wipul Pemsiri Jayasekara, Son Van Nguyen, Sue Zhang
  • Publication number: 20030182790
    Abstract: Methods of making a read head with improved contiguous junctions are described. After sensor layer materials are deposited over a substrate, a lift-off mask is formed over the sensor layer materials in a central region which is surrounded by end regions. Ion milling is performed with use of the lift-off mask such that the sensor layer materials in the end regions are removed and those in the central region remain to form a read sensor. A high-angle ion mill (e.g. between 45-80 degrees) is then performed to remove redeposited material from side walls of the lift-off mask Next, a reactive ion etch (RIE) is used to reduce the thickness and the width of the lift-off mask and to remove capping layer materials from the top edges of the read sensor.
    Type: Application
    Filed: March 28, 2002
    Publication date: October 2, 2003
    Inventors: Richard Hsiao, Wipul Pemsiri Jayasekara, Mustafa Pinarbasi, Patrick Rush Webb
  • Publication number: 20030179496
    Abstract: A read sensor and method of making the same using an etch-stop layer are disclosed. The method is particularly suitable in connection with techniques requiring the partial removal of the capping layer, such as exchange tab (ET) and lead overlay (LOL) techniques. Basically, a thin “etch-stop” layer is deposited over a top free layer of sensor materials. The etch-stop layer is made of a suitable material such as copper oxide (CuO) or nickel-iron-chromium (NiFeCr). A tantalum (Ta) capping layer is then deposited over the etch-stop layer. When appropriate, top edge portions of the capping layer are exposed to a reactive ion etch (RIE) using a fluorine gas for removal. Advantageously, the etch-stop layer significantly reduces or eliminates damage to the free layer that would otherwise occur due to the fluorine gas RIE.
    Type: Application
    Filed: March 22, 2002
    Publication date: September 25, 2003
    Inventor: Wipul Pemsiri Jayasekara