Patents by Inventor Yun-Fei Li

Yun-Fei Li 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: 8146236
    Abstract: A method and system for providing a perpendicular magnetic recording (PMR) transducer from pole layer(s) are disclosed. First and second planarization stop layers are provided on the pole layer(s). A mask is provided on the second planarization stop layer. A first portion of the mask resides on a portion of the pole layer(s) used to form the PMR pole. The PMR pole is defined after the mask is provided. An intermediate layer surrounding at least the PMR pole is provided. A first planarization is performed on at least the intermediate layer. A portion of the second planarization stop layer is removed during the first planarization. A remaining portion of the second planarization stop layer is removed. A second planarization is performed. A portion of the first planarization stop layer remains after the second planarization. A write gap and shield are provided on the PMR pole and write gap, respectively.
    Type: Grant
    Filed: March 28, 2008
    Date of Patent: April 3, 2012
    Assignee: Western Digital (Fremont), LLC
    Inventors: Guanghong Luo, Liubo Hong, Honglin Zhu, Yun-Fei Li, Yingjian Chen
  • Patent number: 8107201
    Abstract: A hard bias structure for biasing a free layer in a MR element within a read head is comprised of a composite hard bias layer having a Co78.6Cr5.2Pt16.2/Co65Cr15Pt20 configuration. The upper Co65Cr15Pt20 layer has a larger Hc value and a thickness about 2 to 10 times greater than that of the Co78.6Cr5.2Pt16.2 layer. The hard bias structure may also include a BCC underlayer such as FeCoMo which enhances the magnetic moment of the hard bias structure. Optionally, the thickness of the Co78.6Cr5.2Pt16.2 layer is zero and the Co65Cr15Pt20 layer is formed on the BCC underlayer. The present invention also encompasses a laminated hard bias structure. The Mrt value for the hard bias structure may be optimized by adjusting the thicknesses of the BCC underlayer and CoCrPt layers. As a result, a larger process window is realized and lower asymmetry output during a read operation is achieved.
    Type: Grant
    Filed: March 5, 2010
    Date of Patent: January 31, 2012
    Assignee: Headway Technologies, Inc.
    Inventors: Kunliang Zhang, Yun-Fei Li, Chyu-Jiuh Torng, Chen-Jung Chien
  • Publication number: 20110279926
    Abstract: A method and system for fabricating magnetic transducer are described. The method and system include providing a main pole having a bottom and a top wider than the bottom. The method and system further include performing a high energy ion mill at an angle from a normal to the top of the main pole and at a first energy. The high energy ion mill removes a portion of the top of the main pole and exposes a top bevel surface for the main pole. The method and system also include performing a low energy ion mill at second energy and a glancing angle from the top bevel surface. The glancing angle is not more than fifteen degrees. The second energy is less than the first energy. The method and system also include depositing a nonmagnetic gap.
    Type: Application
    Filed: May 11, 2010
    Publication date: November 17, 2011
    Applicant: WESTERN DIGITAL (FREMONT), LLC
    Inventors: Weimin Si, Yun-Fei Li, Ying Hong
  • Publication number: 20110086240
    Abstract: Various embodiments of the subject disclosure provide a double patterning process that uses two patterning steps to produce a write structure having a nose shape with sharp corners. In one embodiment, a method for forming a write structure on a multi-layer structure comprising a substrate and an insulator layer on the substrate is provided. The method comprises forming a hard mask layer over the insulator layer, performing a first patterning process to form a pole and yoke opening in the hard mask layer, performing a second patterning process to remove rounded corners of the pole and yoke opening in the hard mask layer, removing a portion of the insulator layer corresponding to the pole and yoke opening in the hard mask layer to form a trench in the insulator layer, and filling the trench with a magnetic material.
    Type: Application
    Filed: October 14, 2009
    Publication date: April 14, 2011
    Applicant: Western Digital (Fremont), LLC
    Inventors: Xiaohai XIANG, Yun-Fei LI, Jinqiu ZHANG, Hongping YUAN, Xianzhong ZENG, Hai SUN
  • Publication number: 20110042349
    Abstract: A method for forming a write pole comprises forming a stop layer over a substrate layer of a wafer, the stop layer having an opening above a damascene trench in the substrate layer, and forming a buffer layer over the stop layer, the buffer layer having an opening above the opening of the stop layer. The method further comprises plating a layer of magnetic material over the wafer, disposing a first sacrificial material over a region of the magnetic material above the damascene trench, performing a milling or etching operation over the wafer to remove the magnetic material not covered by the first sacrificial material and to remove the first sacrificial material, disposing a second sacrificial material over the wafer, and performing a polishing operation over the wafer to remove the region of the magnetic material above the damascene trench, the second sacrificial material, and the buffer layer.
    Type: Application
    Filed: August 20, 2009
    Publication date: February 24, 2011
    Applicant: Western Digital (Fremont), LLC
    Inventors: Ronghui ZHOU, Ming JIANG, Xiaohai XIANG, Jinwen WANG, Guanghong LUO, Yun-Fei LI
  • Patent number: 7819979
    Abstract: A method and system for providing a magnetic structure that includes at least one magnetic material is disclosed. The method and system include defining the magnetic structure. The magnetic structure also includes a top layer that is insensitive to an istroropic carbonyl reactive ion etch. The defining of the magnetic structure results in at least one artifact. The method and system further includes cleaning the at least one artifact using at least one isotropic carbonyl reactive ion etch.
    Type: Grant
    Filed: January 31, 2005
    Date of Patent: October 26, 2010
    Assignee: Western Digital (Fremont), LLC
    Inventors: Benjamin Chen, Yun-Fei Li, Hugh C. Hiner, Wei Zhang, Yingjian Chen
  • Publication number: 20100172053
    Abstract: A hard bias structure for biasing a free layer in a MR element within a read head is comprised of a composite hard bias layer having a Co78.6Cr5.2Pt16.2/Co65Cr15Pt20 configuration. The upper Co65Cr15Pt20 layer has a larger Hc value and a thickness about 2 to 10 times greater than that of the Co78.6Cr5.2Pt16.2 layer. The hard bias structure may also include a BCC underlayer such as FeCoMo which enhances the magnetic moment of the hard bias structure. Optionally, the thickness of the Co78.6Cr5.2Pt16.2 layer is zero and the Co65Cr15Pt20 layer is formed on the BCC underlayer. The present invention also encompasses a laminated hard bias structure. The Mrt value for the hard bias structure may be optimized by adjusting the thicknesses of the BCC underlayer and CoCrPt layers. As a result, a larger process window is realized and lower asymmetry output during a read operation is achieved.
    Type: Application
    Filed: March 5, 2010
    Publication date: July 8, 2010
    Inventors: Kunliang Zhang, Yun-Fei Li, Chyu-Jiuh Torng, Chen-Jung Chien
  • Patent number: 7688555
    Abstract: A hard bias structure for biasing a free layer in a MR element within a read head is comprised of a composite hard bias layer having a Co78.6Cr5.2Pt16.2/Co65Cr15Pt20 configuration. The upper Co65Cr15Pt20 layer has a larger Hc value and a thickness about 2 to 10 times greater than that of the Co78.6Cr5.2Pt16.2 layer. The hard bias structure may also include a BCC underlayer such as FeCoMo which enhances the magnetic moment of the hard bias structure. Optionally, the thickness of the Co78.6Cr5.2Pt16.2 layer is zero and the Co65Cr15Pt20 layer is formed on the BCC underlayer. The present invention also encompasses a laminated hard bias structure. The Mrt value for the hard bias structure may be optimized by adjusting the thicknesses of the BCC underlayer and CoCrPt layers. As a result, a larger process window is realized and lower asymmetry output during a read operation is achieved.
    Type: Grant
    Filed: June 15, 2004
    Date of Patent: March 30, 2010
    Assignee: Headway Technologies, Inc.
    Inventors: Kunliang Zhang, Yun-Fei Li, Chyu-Jiuh Torng, Chen-Jung Chien
  • Patent number: 7529067
    Abstract: Although it is known that exchange bias can be utilized in abutted junctions for longitudinal stabilization, a relatively large moment is needed to pin down the sensor edges effectively. Due to the inverse dependence of the exchange bias on the magnetic layer thickness, a large exchange bias has been difficult to achieve by the prior art. This problem has been solved by introducing a structure in which the magnetic moment of the bias layer has been approximately doubled by pinning it from both above and below through exchange with antiferromagnetic layers. Additionally, since the antiferromagnetic layer is in direct abutted contact with the free layer, it acts directly to help stabilize the sensor edge, which is an advantage over the traditional magnetostatic pinning that had been used.
    Type: Grant
    Filed: March 14, 2006
    Date of Patent: May 5, 2009
    Assignee: Headway Technologies, Inc.
    Inventors: Yun-Fei Li, Hui-Chuan Wang, Chyu-Jiuh Torng, Cherng-Chyi Han, Mao-Min Chen
  • Patent number: 7431961
    Abstract: In this invention, we replace low resistivity NiFe with high-resistivity FeNi for the FL2 portion of a composite free layer in a CIP GMR sensor in order to minimize current shunting effects while still retaining both magnetic softness and low magnetostriction. A process for manufacturing the device is also described.
    Type: Grant
    Filed: December 10, 2004
    Date of Patent: October 7, 2008
    Assignee: Headway Technologies, Inc.
    Inventors: Tong Zhao, Hui-Chuan Wang, Yun-Fei Li, Chyu-Jiuh Torng
  • Patent number: 7400475
    Abstract: Patterned, longitudinally and transversely antiferromagnetically exchange biased GMR sensors are provided which have narrow effective trackwidths and reduced side reading. The exchange biasing significantly reduces signals produced by the portion of the ferromagnetic free layer that is underneath the conducting leads while still providing a strong pinning field to maintain sensor stability. In the case of the transversely biased sensor, the magnetization of the free and biasing layers in the same direction as the pinned layer simplifies the fabrication process and permits the formation of thinner leads by eliminating the necessity for current shunting.
    Type: Grant
    Filed: January 14, 2005
    Date of Patent: July 15, 2008
    Assignee: Headway Technologies, Inc.
    Inventors: Cheng T. Horng, Min Li, Ru-Ying Tong, Yun-Fei Li, You Fong Zheng, Simon Liao, Kochan Ju, Cherng Chyi Han
  • Patent number: 7389577
    Abstract: A method to fabricate a tunneling magnetoresistive (TMR) read transducer is disclosed. An insulative layer is deposited on a wafer substrate, and a bottom lead is deposited over the insulative layer. A laminated TMR layer, having a plurality of laminates, is deposited over the bottom lead. A TMR sensor having a stripe height is defined in the TMR layer, and a parallel resistor and first and second shunt resistors are also defined in the TMR layer. A top lead is deposited over the TMR sensor. The parallel resistor is electrically connected to the bottom lead and to the top lead. The first shunt resistor is electrically connected to the bottom lead and the wafer substrate, and the second shunt resistor is electrically connected to the top lead and the wafer substrate.
    Type: Grant
    Filed: June 26, 2007
    Date of Patent: June 24, 2008
    Assignee: Western Digital (Fremont), LLC
    Inventors: Changhe Shang, Yun-Fei Li, Yining Hu, Yong Shen
  • Patent number: 7336452
    Abstract: In magnetic read heads based on bottom spin valves the preferred structure is for the longitudinal bias layer to be in direct contact with the free layer. Such a structure is very difficult to manufacture. The present invention overcomes this problem by introducing an extra layer between the bias electrodes and the free layer. This layer protects the free layer during processing but is thin enough to not interrupt exchange between the bias electrodes and the free layer. In one embodiment this is a layer of copper about 5 ? thick and parallel exchange is operative. In other embodiments ruthenium is used to provide antiparallel exchange between the bias electrode and the free layer. A process for manufacturing the structure is also described.
    Type: Grant
    Filed: January 14, 2005
    Date of Patent: February 26, 2008
    Assignee: Headway Technologies, Inc.
    Inventors: Moris Dovek, Po-Kang Wang, Chen-Jung Chien, Chyu-Jiuh Torng, Yun-Fei Li
  • Patent number: 7327540
    Abstract: A hard bias layer that forms an abutting junction with a free layer in a GMR element and is comprised of FePtCu or FePtCuX where X is B, C, O, Si, or N is disclosed. The FePtCu layer has a composition of about 45 atomic % Fe, 45 atomic % Pt, and 10 atomic % Cu and does not require a seed layer to achieve an ordered structure. The FePtCu layer is annealed at a temperature of about 280° C. and has an Hc value more than double that of a conventional CoCrPt hard bias layer with a similar thickness. Since the FePtCu hard bias layer adjoins a free layer, it has a higher sensor edge pinning efficiency than a configuration with a CoCrPt layer on a seed layer. The novel hard bias layer is compatible with either a top or bottom spin valve structure in a GMR sensor.
    Type: Grant
    Filed: June 1, 2004
    Date of Patent: February 5, 2008
    Assignee: Headway Technologies, Inc.
    Inventors: Yun-Fei Li, Kunliang Zhang, Chyu-Jiuh Torng
  • Patent number: 7320169
    Abstract: In a conventional spin valve the shunt resistance of the pinning layer reduces the overall efficiency of the device. This problem has been overcome by using IrMn for the pinning layer at a thickness of about 20 Angstroms or less. For the IrMn to be fully effective it must be subjected to a two-step anneal, first in the presence of a high field (about 10 kOe) for several hours and then in a low field (about 500 Oe) while it cools. The result, in addition to improved pinning, is the ability to do testing at the full film and full wafer levels.
    Type: Grant
    Filed: May 14, 2004
    Date of Patent: January 22, 2008
    Assignee: Headway Technologies, Inc.
    Inventors: Yun-Fei Li, Hui-Chuan Wang, Tong Zhao, Chyu-Jiuh Torng
  • Patent number: 7152304
    Abstract: Patterned, longitudinally and transversely antiferromagnetically exchange biased GMR sensors are provided which have narrow effective trackwidths and reduced side reading. The exchange biasing significantly reduces signals produced by the portion of the ferromagnetic free layer that is underneath the conducting leads while still providing a strong pinning field to maintain sensor stability. In the case of the transversely biased sensor, the magnetization of the free and biasing layers in the same direction as the pinned layer simplifies the fabrication process and permits the formation of thinner leads by eliminating the necessity for current shunting.
    Type: Grant
    Filed: January 14, 2005
    Date of Patent: December 26, 2006
    Assignee: Headway Technologies, Inc.
    Inventors: Cheng T. Horng, Min Li, Ru-Ying Tong, Yun-Fei Li, You Fong Zheng, Simon Liao, Kochan Ju, Cherng Chyi Han
  • Patent number: 7134186
    Abstract: Patterned, longitudinally and transversely antiferromagnetically exchange biased GMR sensors are provided which have narrow effective trackwidths and reduced side reading. The exchange biasing significantly reduces signals produced by the portion of the ferromagnetic free layer that is underneath the conducting leads while still providing a strong pinning field to maintain sensor stability. In the case of the transversely biased sensor, the magnetization of the free and biasing layers in the same direction as the pinned layer simplifies the fabrication process and permits the formation of thinner leads by eliminating the necessity for current shunting.
    Type: Grant
    Filed: January 14, 2005
    Date of Patent: November 14, 2006
    Assignee: Headway Technologies, Inc.
    Inventors: Cheng T. Horng, Min Li, Ru-Ying Tong, Yun-Fei Li, You Fong Zheng, Simon Liao, Kochan Ju, Cherng Chyi Han
  • Patent number: 7099125
    Abstract: A problem associated with current bottom spin valve designs is that it is difficult to avoid magnetic charge accumulation at the edge of the sensor area, making a coherent spin rotation during sensing difficult to achieve. This problem has been eliminated by introducing an exchange coupling layer between the free layer and the ferromagnetic layer that is used to achieve longitudinal bias for stabilization and by extending the free layer well beyond the sensor area. After all layers have been deposited, the read gap is formed by etching down as far as this layer. Since it is not critical exactly how much of the biasing layers (antiferromagnetic as well as ferromagnetic) are removed, the etching requirements are greatly relaxed. Whatever material remains in the gap is then oxidized thereby providing a capping layer as well as a good interface for specular reflection in the sensor region.
    Type: Grant
    Filed: November 7, 2005
    Date of Patent: August 29, 2006
    Assignee: Headway Technologies, Inc.
    Inventors: Yun-Fei Li, Hui-Chuan Wang, Chyu-Jiuh Torng, Cherng Chyi Han
  • Publication number: 20060164766
    Abstract: Although it is known that exchange bias can be utilized in abutted junctions for longitudinal stabilization, a relatively large moment is needed to pin down the sensor edges effectively. Due to the inverse dependence of the exchange bias on the magnetic layer thickness, a large exchange bias has been difficult to achieve by the prior art. This problem has been solved by introducing a structure in which the magnetic moment of the bias layer has been approximately doubled by pinning it from both above and below through exchange with antiferromagnetic layers. Additionally, since the antiferromagnetic layer is in direct abutted contact with the free layer, it acts directly to help stabilize the sensor edge, which is an advantage over the traditional magnetostatic pinning that had been used.
    Type: Application
    Filed: March 14, 2006
    Publication date: July 27, 2006
    Inventors: Yun-Fei Li, Hui-Chuan Wang, Chyu-Jiuh Torng, Cherng-Chyi Han, Mao-Min Chen
  • Publication number: 20060126231
    Abstract: In this invention, we replace low resistivity NiFe with high-resistivity FeNi for the FL2 portion of a composite free layer in a CIP GMR sensor in order to minimize current shunting effects while still retaining both magnetic softness and low magnetostriction. A process for manufacturing the device is also described.
    Type: Application
    Filed: December 10, 2004
    Publication date: June 15, 2006
    Inventors: Tong Zhao, Hui-Chuan Wang, Yun-Fei Li, Chyu-Jiuh Torng