Patents by Inventor Yewhee Chye
Yewhee Chye 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).
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Publication number: 20230258747Abstract: A composite hard mask is disclosed. In some embodiments, a first sacrificial hard mask layer comprising an amorphous carbon or silicon nitride and a second sacrificial hard mask layer comprising a silicon nitride, silicon oxide, metal, metal oxide, or metal nitride, wherein the first and second sacrificial hard mask layers are not made of the same material.Type: ApplicationFiled: February 14, 2022Publication date: August 17, 2023Inventors: Tom Zhong, Min Li, Ruhang Ding, Hiroshi Omine, QingJun Qin, Richard Zhou, Yunqing Cai, Yewhee Chye, Minghui Yu
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Patent number: 11217274Abstract: 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: GrantFiled: February 7, 2020Date of Patent: January 4, 2022Assignee: Headway Technologies, Inc.Inventors: Junjie Quan, Glen Garfunkel, Yewhee Chye, Kunliang Zhang, Min Li
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Patent number: 10950261Abstract: The use of supermalloy-like materials such as NiFeMe where Me is one or more of Mo, Cr, and Cu for the side and top shields of a magnetic bit sensor is shown to provide better shielding protection from stray fields because of their extremely high permeability. Moreover, the side shield may comprise a stack in which a Ni, Fe, Co, FeNi, CoFe, or FeCo is sandwiched between two NiFeMe layers to enhance the bias field on an adjacent free layer. Including NiFeMe in a side shield results in an increase in readback amplitude under the same asymmetric sigma. For these sensors, the signal to noise ratio was higher and the bit error rate was lower than with conventional materials in the side shield. A method is disclosed for forming a magnetic bit sensor having supermalloy-like materials in the side shields.Type: GrantFiled: August 28, 2018Date of Patent: March 16, 2021Assignee: Headway Technologies, Inc.Inventors: Yewhee Chye, Kunliang Zhang, Min Li
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Publication number: 20200176024Abstract: 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: ApplicationFiled: February 7, 2020Publication date: June 4, 2020Inventors: Junjie Quan, Glen Garfunkel, Yewhee Chye, Kunliang Zhang, Min Li
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Patent number: 10593357Abstract: 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: GrantFiled: October 16, 2018Date of Patent: March 17, 2020Assignee: Headway Technologies, Inc.Inventors: Junjie Quan, Glen Garfunkel, Yewhee Chye, Kunliang Zhang, Min Li
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Publication number: 20190051321Abstract: 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: ApplicationFiled: October 16, 2018Publication date: February 14, 2019Inventors: Junjie Quan, Glen Garfunkel, Yewhee Chye, Kunliang Zhang, Min Li
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Publication number: 20190013041Abstract: The use of supermalloy-like materials such as NiFeMe where Me is one or more of Mo, Cr, and Cu for the side and top shields of a magnetic bit sensor is shown to provide better shielding protection from stray fields because of their extremely high permeability. Moreover, the side shield may comprise a stack in which a Ni, Fe, Co, FeNi, CoFe, or FeCo is sandwiched between two NiFeMe layers to enhance the bias field on an adjacent free layer. Including NiFeMe in a side shield results in an increase in readback amplitude under the same asymmetric sigma. For these sensors, the signal to noise ratio was higher and the bit error rate was lower than with conventional materials in the side shield. A method is disclosed for forming a magnetic bit sensor having supermalloy-like materials in the side shields.Type: ApplicationFiled: August 28, 2018Publication date: January 10, 2019Inventors: Yewhee Chye, Kunliang Zhang, Min Li
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Patent number: 10157634Abstract: A process flow is disclosed for forming a MR sensor having an antiferromagnetic (AFM) layer recessed behind a bottom shield to reduce reader shield spacing and improve pin related noise. An AP2/AFM coupling layer/AP1 stack that extends from an air bearing surface to the MR sensor backside is formed above the AFM layer. The AP2 layer is pinned by the AFM layer, and the AP1 layer serves as a reference layer to an overlying free layer during a read operation. The AP1 and AP2 layers have improved resistance to magnetization flipping because back portions thereof have a full cross-track width “w” between MR sensor sides thereby enabling greater pinning strength from the AFM layer. Front portions of the AP1/AP2 layers lie under the free layer and have a track width less than “w”. The bottom shield may have an anti-ferromagnetic coupling structure.Type: GrantFiled: October 23, 2017Date of Patent: December 18, 2018Assignee: Headway Technologies, Inc.Inventors: Ruhang Ding, Yewhee Chye, Wenyu Chen, Kunliang Zhang, Yan Wu, Min Li
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Patent number: 10115418Abstract: 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: GrantFiled: November 21, 2016Date of Patent: October 30, 2018Assignee: Headway Technologies, Inc.Inventors: Junjie Quan, Glen Garfunkel, Yewhee Chye, Kunliang Zhang, Min Li
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Publication number: 20180144766Abstract: 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: ApplicationFiled: November 21, 2016Publication date: May 24, 2018Inventors: Junjie Quan, Glen Garfunkel, Yewhee Chye, Kunliang Zhang, Min Li
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Publication number: 20180130487Abstract: A process flow is disclosed for forming a MR sensor having an antiferromagnetic (AFM) layer recessed behind a bottom shield to reduce reader shield spacing and improve pin related noise. An AP2/AFM coupling layer/AP1 stack that extends from an air bearing surface to the MR sensor backside is formed above the AFM layer. The AP2 layer is pinned by the AFM layer, and the AP1 layer serves as a reference layer to an overlying free layer during a read operation. The AP1 and AP2 layers have improved resistance to magnetization flipping because back portions thereof have a full cross-track width “w” between MR sensor sides thereby enabling greater pinning strength from the AFM layer. Front portions of the AP1/AP2 layers lie under the free layer and have a track width less than “w”. The bottom shield may have an anti-ferromagnetic coupling structure.Type: ApplicationFiled: October 23, 2017Publication date: May 10, 2018Inventors: Ruhang Ding, Yewhee Chye, Wenyu Chen, Kunliang Zhang, Yan Wu, Min Li
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Patent number: 9799357Abstract: A MR sensor is disclosed with an antiferromagnetic (AFM) layer recessed behind a bottom shield to reduce reader shield spacing and improve pin related noise. Above the AFM layer is an AP2/AFM coupling layer/AP1 stack that extends from an air bearing surface to the MR sensor backside. The AP2 layer is pinned by the AFM layer, and the AP1 layer serves as a reference layer to an overlying free layer during a read operation. The AP1 and AP2 layers have improved resistance to magnetization flipping because back portions thereof have a full cross-track width “w” between MR sensor sides thereby enabling greater pinning strength from the AFM layer. Front portions of the AP1/AP2 layers lie under the free layer and have a track width less than “w”. The bottom shield may have an anti-ferromagnetic coupling structure. A process flow is provided for fabricating the MR sensor.Type: GrantFiled: November 8, 2016Date of Patent: October 24, 2017Assignee: Headway Technologies, Inc.Inventors: Ruhang Ding, Yewhee Chye, Wenyu Chen, Kunliang Zhang, Min Li
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Publication number: 20170084296Abstract: 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: ApplicationFiled: November 30, 2016Publication date: March 23, 2017Inventors: Glen Garfunkel, Yan Wu, Junjie Quan, Yewhee Chye
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Patent number: 9601138Abstract: 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: GrantFiled: September 9, 2015Date of Patent: March 21, 2017Assignee: Headway Technologies, Inc.Inventors: Glen Garfunkel, Yan Wu, Junjie Quan, Yewhee Chye
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Publication number: 20170069341Abstract: 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: ApplicationFiled: September 9, 2015Publication date: March 9, 2017Inventors: Glen Garfunkel, Yan Wu, Junjie Quan, Yewhee Chye
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Publication number: 20170025135Abstract: The use of supermalloy-like materials such as NiFeMe where Me is one or more of Mo, Cr, and Cu for the side and top shields of a magnetic bit sensor is shown to provide better shielding protection from stray fields because of their extremely high permeability. Moreover, the side shield may comprise a stack in which a Ni, Fe, Co, FeNi, CoFe, or FeCo is sandwiched between two NiFeMe layers to enhance the bias field on an adjacent free layer. Including NiFeMe in a side shield results in an increase in readback amplitude under the same asymmetric sigma. For these sensors, the signal to noise ratio was higher and the bit error rate was lower than with conventional materials in the side shield.Type: ApplicationFiled: October 3, 2016Publication date: January 26, 2017Inventors: Yewhee Chye, Kunliang Zhang, Min Li
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Patent number: 9515253Abstract: 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: GrantFiled: June 24, 2015Date of Patent: December 6, 2016Assignee: Headway Technologies, Inc.Inventors: Kunliang Zhang, Hui-Chuan Wang, Junjie Quan, Yewhee Chye, Min Li
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Patent number: 9460737Abstract: The use of supermalloy-like materials for the side and top shields of a magnetic bit sensor is shown to provide better shielding protection from stray fields because of their extremely high permeability.Type: GrantFiled: April 18, 2013Date of Patent: October 4, 2016Assignee: Headway Technologies, Inc.Inventors: Yewhee Chye, Kunliang Zhang, Min Li
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Patent number: 9437225Abstract: 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: GrantFiled: July 29, 2014Date of Patent: September 6, 2016Assignee: Headway Technologies, Inc.Inventors: Junjie Quan, Kunliang Zhang, Min Li, Ruhang Ding, Yewhee Chye, Glen Garfunkel, Wenyu Chen
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Publication number: 20160035378Abstract: 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: ApplicationFiled: July 29, 2014Publication date: February 4, 2016Inventors: Junjie Quan, Kunliang Zhang, Min Li, Ruhang Ding, Yewhee Chye, Glen Garfunkel, Wenyu Chen