Patents by Inventor Thomas L. Leong

Thomas L. Leong 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: 9053721
    Abstract: A magnetic read sensor having a magnetic seed layer, a pinned layer structure formed over the magnetic seed layer, a non-magnetic barrier or spacer layer formed over the pinned layer structure and a magnetic free layer structure formed over the non-magnetic barrier or spacer layer. The pinned layer has a stripe height (measured from the media facing surface) that is greater than a stripe height of the magnetic free layer structure. In addition, the magnetic seed layer structure has a stripe height (also measured from the media facing surface) that is greater than the stripe height of the magnetic pinned layer structure and the magnetic free layer structure. The stripe height of the magnetic seed layer structure can be controlled independently of the stripe heights of the magnetic pinned layer structure and the magnetic free layer structure.
    Type: Grant
    Filed: May 30, 2014
    Date of Patent: June 9, 2015
    Assignee: HGST Netherlands B.V.
    Inventors: Yongchul Ahn, David P. Druist, Zheng Gao, Ying Hong, Yunhe Huang, Quang Le, Thomas L. Leong, Guangli Liu, Xiaoyong Liu, David J. Seagle
  • Patent number: 8296930
    Abstract: A method for manufacturing a magnetoresistive sensor that results in the sensor having a very flat top magnetic shield. The process involves depositing a plurality of sensor layers and then depositing a thin high density carbon CMP stop layer over the sensor layers and forming a mask over the CMP stop layer. An ion milling is performed to define the sensor. Then a thin insulating layer and magnetic hard bias layer are deposited. A chemical mechanical polishing is performed to remove the mask and a reactive ion etching is performed to remove the remaining carbon CMP stop layer. Because the CMP stop layer is very dense and hard, it can be made very thin. This means that when it is removed by reactive ion etching, there is very little notching over the sensor, thereby allowing the upper shield to be very thin.
    Type: Grant
    Filed: December 22, 2009
    Date of Patent: October 30, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Shin Funada, Quang Le, Thomas L. Leong, Jui-Lung Li, Chang-Man Park, Ning Shi, Hicham M. Sougrati
  • Publication number: 20110146061
    Abstract: A method for manufacturing a magnetoresistive sensor that results in the sensor having a very flat top magnetic shield. The process involves depositing a plurality of sensor layers and then depositing a thin high density carbon CMP stop layer over the sensor layers and forming a mask over the CMP stop layer. An ion milling is performed to define the sensor. Then a thin insulating layer and magnetic hard bias layer are deposited. A chemical mechanical polishing is performed to remove the mask and a reactive ion etching is performed to remove the remaining carbon CMP stop layer. Because the CMP stop layer is very dense and hard, it can be made very thin. This means that when it is removed by reactive ion etching, there is very little notching over the sensor, thereby allowing the upper shield (deposited there-over) to be very thin.
    Type: Application
    Filed: December 22, 2009
    Publication date: June 23, 2011
    Inventors: Shin Funada, Quang Le, Thomas L. Leong, Jui-Lung Li, Chang-Man Park, Ning Shi, Hicham M. Sougrati
  • Patent number: 7530158
    Abstract: A method is disclosed for fabricating a CPP read head for a magnetic disk drive having an electrical isolation layer. The method includes providing a first shield layer, depositing a sensor stack on the first shield layer, a CMP stop layer is deposited on the sensor stack, and a release layer is deposited a on the CMP stop layer. Photoresist material containing Si is deposited on the release layer, and the photoresist material is then patterned and then oxidized by Reactive Ion Etching to form a high temperature photomask. The electrical isolation layer is then deposited to surround the sensor stack using a high temperature deposition process. The read head is then continued as either an in-stack bias sensor with ‘draped shield’ variation, or a hard bias stabilization variation.
    Type: Grant
    Filed: April 19, 2005
    Date of Patent: May 12, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Satoru Araki, Robert Stanley Beach, Ying Hong, Thomas L. Leong, Timothy J. Minvielle, Howard Gordon Zolla
  • Patent number: 7186574
    Abstract: A method for forming metrology structures for a CMP process is described. A trench edge is formed in a base material or stack of materials which are preferably deposited as part of the process of fabricating the production structures on the wafer. A covering film of a second material with preferably with contrasting SEM properties is deposited over the trench edge in the base material. During CMP the covering film is preferentially worn away at the edge revealing the base material. The width of the base material which has been revealed is a measure of the progress of the CMP. Since the base material and the covering material are preferably selected to have contrasting images in an SEM, a CD-SEM can be used to precisely measure the CMP progress.
    Type: Grant
    Filed: September 30, 2004
    Date of Patent: March 6, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Sukhbir Singh Dulay, Thomas L. Leong, John Jaekoyun Yang
  • Patent number: 6929961
    Abstract: CMP process control array groups are fabricated upon the surface of the wafer for viewing through an optical microscope. The array groups include a plurality of test arrays, where each array includes a plurality of projecting test features. Each of the projecting test features are formed with the same projecting height and have a hard upper surface layer, such as diamond-like-carbon (DLC). All of the projecting test features within an array are formed with the same diameter, and the diameter of projecting test features of a particular array differs from the diameter of projecting test features in another array. The diameters are chosen such that the DLC surface is removed in specifically designed time increments, such as 5 seconds, from array to array, where projecting test features with the DLC surface removed appear as bright white, while the arrays with test features that retain some DLC surface are significantly darker.
    Type: Grant
    Filed: December 10, 2003
    Date of Patent: August 16, 2005
    Assignee: Hitachi Global Storage Technologies Netherlands B. V.
    Inventors: Justin Jia-Jen Hwu, Thomas L. Leong
  • Patent number: 5277749
    Abstract: A layer of photoresist provides a stress relief (or cushion) layer between a lift-off polymer layer and a barrier of multi-level lift-off structures. When multiple evaporation steps are required using the same lift-off pattern, the adhesion between organosilicon and organic film is stressed by a first blanked metal film. To prevent delamination between the lift-off polymer layer and RIE barrier photoresist is applied on top of the lift-off polymer and sandwiched between the organosilicon and organic materials. This photoresist acts as a cushion and as an adhesion promoter to reduce delamination after the metal deposition(s).
    Type: Grant
    Filed: October 17, 1991
    Date of Patent: January 11, 1994
    Assignee: International Business Machines Corporation
    Inventors: Jonathan H. Griffith, John I. Kim, Thomas L. Leong, William J. Tilly, Sari Wacks