Patents by Inventor Junjie Quan

Junjie Quan 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: 11217274
    Abstract: A hard magnet stabilization scheme is disclosed for a top shield and junction shields for double or triple dimension magnetic reader structures. In one design, the hard magnet (HM) adjoins a top or bottom surface of all or part of a shield domain such that the HM is recessed from the air bearing surface to satisfy reader-to-reader spacing requirements and stabilizes a closed loop magnetization in the top shield. The HM may have a height and width greater than that of the top shield. The top shield may have a ring shape with a HM formed above, below, or within the ring shape, and wherein the HM stabilizes a vortex magnetization. HM magnetization is set or reset from room temperature to 100° C. to maintain a desired magnetization direction in the top shield, junction shield, and free layer in the sensor.
    Type: Grant
    Filed: February 7, 2020
    Date of Patent: January 4, 2022
    Assignee: Headway Technologies, Inc.
    Inventors: Junjie Quan, Glen Garfunkel, Yewhee Chye, Kunliang Zhang, Min Li
  • Publication number: 20200176024
    Abstract: A hard magnet stabilization scheme is disclosed for a top shield and junction shields for double or triple dimension magnetic reader structures. In one design, the hard magnet (HM) adjoins a top or bottom surface of all or part of a shield domain such that the HM is recessed from the air bearing surface to satisfy reader-to-reader spacing requirements and stabilizes a closed loop magnetization in the top shield. The HM may have a height and width greater than that of the top shield. The top shield may have a ring shape with a HM formed above, below, or within the ring shape, and wherein the HM stabilizes a vortex magnetization. HM magnetization is set or reset from room temperature to 100° C. to maintain a desired magnetization direction in the top shield, junction shield, and free layer in the sensor.
    Type: Application
    Filed: February 7, 2020
    Publication date: June 4, 2020
    Inventors: Junjie Quan, Glen Garfunkel, Yewhee Chye, Kunliang Zhang, Min Li
  • Patent number: 10593357
    Abstract: A hard magnet stabilization scheme is disclosed for a top shield and junction shields for double or triple dimension magnetic reader structures. In one design, the hard magnet (HM) adjoins a top or bottom surface of all or part of a shield domain such that the HM is recessed from the air bearing surface to satisfy reader-to-reader spacing requirements and stabilizes a closed loop magnetization in the top shield. The HM may have a height and width greater than that of the top shield. The top shield may have a ring shape with a HM formed above, below, or within the ring shape, and wherein the HM stabilizes a vortex magnetization. HM magnetization is set or reset from room temperature to 100° C. to maintain a desired magnetization direction in the top shield, junction shield, and free layer in the sensor.
    Type: Grant
    Filed: October 16, 2018
    Date of Patent: March 17, 2020
    Assignee: Headway Technologies, Inc.
    Inventors: Junjie Quan, Glen Garfunkel, Yewhee Chye, Kunliang Zhang, Min Li
  • Publication number: 20190051321
    Abstract: A hard magnet stabilization scheme is disclosed for a top shield and junction shields for double or triple dimension magnetic reader structures. In one design, the hard magnet (HM) adjoins a top or bottom surface of all or part of a shield domain such that the HM is recessed from the air bearing surface to satisfy reader-to-reader spacing requirements and stabilizes a closed loop magnetization in the top shield. The HM may have a height and width greater than that of the top shield. The top shield may have a ring shape with a HM formed above, below, or within the ring shape, and wherein the HM stabilizes a vortex magnetization. HM magnetization is set or reset from room temperature to 100° C. to maintain a desired magnetization direction in the top shield, junction shield, and free layer in the sensor.
    Type: Application
    Filed: October 16, 2018
    Publication date: February 14, 2019
    Inventors: Junjie Quan, Glen Garfunkel, Yewhee Chye, Kunliang Zhang, Min Li
  • Patent number: 10115418
    Abstract: A hard magnet stabilization scheme is disclosed for a top shield and junction shields for double or triple dimension magnetic reader structures. In one design, the hard magnet (HM) adjoins a top or bottom surface of all or part of a shield domain such that the HM is recessed from the air bearing surface to satisfy reader-to-reader spacing requirements and stabilizes a closed loop magnetization in the top shield. Alternatively, the HM may replace a shield domain. The top shield may have various shapes including a ring shape in which the HM stabilizes a vortex magnetization. In a whole shield coupling design, the HM contacts all of the top shield bottom surface except over the sensor and junction shield. HM magnetization is set or reset from room temperature to 100° C. to maintain a desired magnetization direction in the top shield, junction shield, and free layer in the sensor.
    Type: Grant
    Filed: November 21, 2016
    Date of Patent: October 30, 2018
    Assignee: Headway Technologies, Inc.
    Inventors: Junjie Quan, Glen Garfunkel, Yewhee Chye, Kunliang Zhang, Min Li
  • Publication number: 20180144766
    Abstract: A hard magnet stabilization scheme is disclosed for a top shield and junction shields for double or triple dimension magnetic reader structures. In one design, the hard magnet (HM) adjoins a top or bottom surface of all or part of a shield domain such that the HM is recessed from the air bearing surface to satisfy reader-to-reader spacing requirements and stabilizes a closed loop magnetization in the top shield. Alternatively, the HM may replace a shield domain. The top shield may have various shapes including a ring shape in which the HM stabilizes a vortex magnetization. In a whole shield coupling design, the HM contacts all of the top shield bottom surface except over the sensor and junction shield. HM magnetization is set or reset from room temperature to 100° C. to maintain a desired magnetization direction in the top shield, junction shield, and free layer in the sensor.
    Type: Application
    Filed: November 21, 2016
    Publication date: May 24, 2018
    Inventors: Junjie Quan, Glen Garfunkel, Yewhee Chye, Kunliang Zhang, Min Li
  • Publication number: 20170084296
    Abstract: A read head is longitudinally biased unidirectionally by laterally abutting soft magnetic layers or multilayers. The soft magnetic layers are themselves magnetically stabilized by layers of antiferromagnetic material that are exchange coupled to them. The same layers of antiferromagnetic materials can be used to stabilize a unidirectional anisotropy of an overhead shield by means of exchange coupling. By including the antiferromagnetic material layer within the patterned biasing structure itself, an additional layer of antiferromagnetic material that normally covers the entire sensor structure is eliminated. The elimination of an entire layer is also advantageous for reducing the inter-sensor spacing in a TDMR (two dimensional magnetic recording) configuration where two sensor are vertically stacked on top of each other.
    Type: Application
    Filed: November 30, 2016
    Publication date: March 23, 2017
    Inventors: Glen Garfunkel, Yan Wu, Junjie Quan, Yewhee Chye
  • Patent number: 9601138
    Abstract: A read head is longitudinally biased unidirectionally by laterally abutting soft magnetic layers or multilayers. The soft magnetic layers are themselves magnetically stabilized by layers of antiferromagnetic material that are exchange coupled to them. The same layers of antiferromagnetic materials can be used to stabilize a unidirectional anisotropy of an overhead shield by means of exchange coupling. By including the antiferromagnetic material layer within the patterned biasing structure itself, an additional layer of antiferromagnetic material that normally covers the entire sensor structure is eliminated. The elimination of an entire layer is also advantageous for reducing the inter-sensor spacing in a TDMR (two dimensional magnetic recording) configuration where two sensor are vertically stacked on top of each other.
    Type: Grant
    Filed: September 9, 2015
    Date of Patent: March 21, 2017
    Assignee: Headway Technologies, Inc.
    Inventors: Glen Garfunkel, Yan Wu, Junjie Quan, Yewhee Chye
  • Patent number: 9601137
    Abstract: A method of forming a magnetoresistive (MR) sensor with a composite tunnel barrier comprised primarily of magnesium oxynitride and having a MR ratio of at least 70%, resistance x area (RA) product <1 ohm-?m2, and fewer pinholes than a conventional MgO layer is disclosed. The method involves forming a Mg/MgON/Mg, Mg/MgON/MgN, MgN/MgON/MgN, or MgN/MgON/Mg intermediate tunnel barrier stack and then annealing to drive loosely bound oxygen into adjacent layers thereby forming MgO/MgON/Mg, MgO/MgON/MgON, MgON/MgON/MgON, and MgON/MgON/MgO composite tunnel barriers, respectively, wherein oxygen content in the middle MgON layer is greater than in upper and lower MgON layers. The MgON layer in the intermediate tunnel barrier may be formed by a sputtering process followed by a natural oxidation step and has a thickness greater than the Mg and MgN layers.
    Type: Grant
    Filed: December 19, 2014
    Date of Patent: March 21, 2017
    Assignee: Headway Technologies, Inc.
    Inventors: Kunliang Zhang, Hui-Chuan Wang, Junjie Quan, Min Li
  • Publication number: 20170069341
    Abstract: A read head is longitudinally biased unidirectionally by laterally abutting soft magnetic layers or multilayers. The soft magnetic layers are themselves magnetically stabilized by layers of antiferromagnetic material that are exchange coupled to them. The same layers of antiferromagnetic materials can be used to stabilize a unidirectional anisotropy of an overhead shield by means of exchange coupling. By including the antiferromagnetic material layer within the patterned biasing structure itself, an additional layer of antiferromagnetic material that normally covers the entire sensor structure is eliminated. The elimination of an entire layer is also advantageous for reducing the inter-sensor spacing in a TDMR (two dimensional magnetic recording) configuration where two sensor are vertically stacked on top of each other.
    Type: Application
    Filed: September 9, 2015
    Publication date: March 9, 2017
    Inventors: Glen Garfunkel, Yan Wu, Junjie Quan, Yewhee Chye
  • Patent number: 9515253
    Abstract: A TMR stack or a GMR stack, ultimately formed into a sensor or MRAM element, include insertion layers of Fe or iron rich layers of FeX in its ferromagnetic free layer and/or the AP1 layer of its SyAP pinned layer. X is a non-magnetic, metallic element (or elements) chosen from Ta, Hf, V, Co, Mo, Zr, Nb or Ti whose total atom percent is less than 50%. The insertion layers are between 1 and 10 angstroms in thickness, with between 2 and 5 angstroms being preferred and, in the TMR stack, they are inserted adjacent to the interfaces between a tunneling barrier layer and the ferromagnetic free layer or the tunneling barrier layer and the AP1 layer of the SyAP pinned layer in the TMR stack. The insertion layers constrain interdiffusion of B and Ni from CoFeB and NiFe layers and block NiFe crystalline growth.
    Type: Grant
    Filed: June 24, 2015
    Date of Patent: December 6, 2016
    Assignee: Headway Technologies, Inc.
    Inventors: Kunliang Zhang, Hui-Chuan Wang, Junjie Quan, Yewhee Chye, Min Li
  • Patent number: 9437225
    Abstract: A MR sensor is disclosed with an antiferromagnetic (AFM) layer recessed behind a first stack of layers including a free layer and non-magnetic spacer to reduce reader shield spacing and enable increased areal density. The AFM layer may be formed on a first pinned layer in the first stack that is partially embedded in a second pinned layer having a front portion at an air bearing surface (ABS) to improve pinning strength and avoid a morphology effect. In another embodiment, the AFM layer is embedded in a bottom shield and surrounds the sidewalls and back side of an overlying free layer in the sensor stack to reduce reader shield spacing. Pinning strength is improved because of increased contact between the AFM layer and a pinned layer. The free layer is aligned above a bottom shield center section.
    Type: Grant
    Filed: July 29, 2014
    Date of Patent: September 6, 2016
    Assignee: Headway Technologies, Inc.
    Inventors: Junjie Quan, Kunliang Zhang, Min Li, Ruhang Ding, Yewhee Chye, Glen Garfunkel, Wenyu Chen
  • Publication number: 20160180869
    Abstract: A method of forming a magnetoresistive (MR) sensor with a composite tunnel barrier comprised primarily of magnesium oxynitride and having a MR ratio of at least 70%, resistance x area (RA) product <1 ohm-?m2, and fewer pinholes than a conventional MgO layer is disclosed. The method involves forming a Mg/MgON/Mg, Mg/MgON/MgN, MgN/MgON/MgN, or MgN/MgON/Mg intermediate tunnel barrier stack and then annealing to drive loosely bound oxygen into adjacent layers thereby forming MgO/MgON/Mg, MgO/MgON/MgON, MgON/MgON/MgON, and MgON/MgON/MgO composite tunnel barriers, respectively, wherein oxygen content in the middle MgON layer is greater than in upper and lower MgON layers. The MgON layer in the intermediate tunnel barrier may be formed by a sputtering process followed by a natural oxidation step and has a thickness greater than the Mg and MgN layers.
    Type: Application
    Filed: December 19, 2014
    Publication date: June 23, 2016
    Inventors: Kunliang Zhang, Hui-Chuan Wang, Junjie Quan, Min Li
  • Patent number: 9281469
    Abstract: The blocking temperature of the AFM layer in a TMR sensor has been raised by inserting a magnetic seed layer between the AFM layer and the bottom shield. This gives the device improved thermal stability, including improved SNR and BER.
    Type: Grant
    Filed: December 23, 2014
    Date of Patent: March 8, 2016
    Assignee: Headway Technologies, Inc.
    Inventors: Junjie Quan, Kunliang Zhang, Min Li, Hui-Chuan Wang
  • Publication number: 20160035378
    Abstract: A MR sensor is disclosed with an antiferromagnetic (AFM) layer recessed behind a first stack of layers including a free layer and non-magnetic spacer to reduce reader shield spacing and enable increased areal density. The AFM layer may be formed on a first pinned layer in the first stack that is partially embedded in a second pinned layer having a front portion at an air bearing surface (ABS) to improve pinning strength and avoid a morphology effect. In another embodiment, the AFM layer is embedded in a bottom shield and surrounds the sidewalls and back side of an overlying free layer in the sensor stack to reduce reader shield spacing. Pinning strength is improved because of increased contact between the AFM layer and a pinned layer. The free layer is aligned above a bottom shield center section.
    Type: Application
    Filed: July 29, 2014
    Publication date: February 4, 2016
    Inventors: Junjie Quan, Kunliang Zhang, Min Li, Ruhang Ding, Yewhee Chye, Glen Garfunkel, Wenyu Chen
  • Publication number: 20150295168
    Abstract: A TMR stack or a GMR stack, ultimately formed into a sensor or MRAM element, include insertion layers of Fe or iron rich layers of FeX in its ferromagnetic free layer and/or the AP1 layer of its SyAP pinned layer. X is a non-magnetic, metallic element (or elements) chosen from Ta, Hf, V, Co, Mo, Zr, Nb or Ti whose total atom percent is less than 50%. The insertion layers are between 1 and 10 angstroms in thickness, with between 2 and 5 angstroms being preferred and, in the TMR stack, they are inserted adjacent to the interfaces between a tunneling barrier layer and the ferromagnetic free layer or the tunneling barrier layer and the AP1 layer of the SyAP pinned layer in the TMR stack. The insertion layers constrain interdiffusion of B and Ni from CoFeB and NiFe layers and block NiFe crystalline growth.
    Type: Application
    Filed: June 24, 2015
    Publication date: October 15, 2015
    Inventors: Kunliang Zhang, Hui-Chuan Wang, Junjie Quan, Yewhee Chye, Min Li
  • Patent number: 9123886
    Abstract: A wrap around shield structure is disclosed for biasing a free layer in a sensor and includes a bottom shield, side shields, and top shield in which each shield element comprises a high moment layer with a magnetization saturation greater than that of Ni70Fe30. The high moment layers provide a better micro read width performance. Side shield structure includes a stack of antiferromagnetically (AFM) coupled magnetic layers on a second high moment layer. A first (lower) magnetic layer in each side shield is ferromagnetically coupled to the second high moment layer, and to a first high moment layer in the bottom shield. A third (upper) magnetic layer in each side shield is ferromagnetically coupled to a third high moment layer in the top shield for improved stabilization. Sensor sidewalls may terminate at a top surface of a reference layer to decrease reader shield spacing.
    Type: Grant
    Filed: March 5, 2013
    Date of Patent: September 1, 2015
    Assignee: Headway Technologies, Inc.
    Inventors: Kunliang Zhang, Min Li, Junjie Quan, Yewhee Chye
  • Patent number: 9082872
    Abstract: A TMR stack or a GMR stack, ultimately formed into a sensor or MRAM element, include insertion layers of Fe or iron rich layers of FeX in its ferromagnetic free layer and/or the AP1 layer of its SyAP pinned layer. X is a non-magnetic, metallic element (or elements) chosen from Ta, Hf, V, Co, Mo, Zr, Nb or Ti whose total atom percent is less than 50%. The insertion layers are between 1 and 10 angstroms in thickness, with between 2 and 5 angstroms being preferred and, in the TMR stack, they are inserted adjacent to the interfaces between a tunneling barrier layer and the ferromagnetic free layer or the tunneling barrier layer and the AP1 layer of the SyAP pinned layer in the TMR stack. The insertion layers constrain interdiffusion of B and Ni from CoFeB and NiFe layers and block NiFe crystalline growth.
    Type: Grant
    Filed: January 2, 2013
    Date of Patent: July 14, 2015
    Assignee: Headway Technologies, Inc.
    Inventors: Kunliang Zhang, Hui-Chuan Wang, Junjie Quan, Yewhee Chye, Min Li
  • Publication number: 20150108593
    Abstract: The blocking temperature of the AFM layer in a TMR sensor has been raised by inserting a magnetic seed layer between the AFM layer and the bottom shield. This gives the device improved thermal stability, including improved SNR and BER.
    Type: Application
    Filed: December 23, 2014
    Publication date: April 23, 2015
    Inventors: Junjie Quan, Kunliang Zhang, Min Li, Hui-Chuan Wang
  • Patent number: 9001472
    Abstract: An apparatus includes a sensor stack, first and second shields positioned on opposite sides of the sensor stack, and a first shield stabilization structure adjacent to the first shield and applying a bias magnetic field to the first shield. A second shield stabilization structure can be positioned adjacent to the second shield.
    Type: Grant
    Filed: December 17, 2013
    Date of Patent: April 7, 2015
    Assignee: Seagate Technology LLC
    Inventors: Eric Walter Singleton, Junjie Quan, Jae-Young Yi