Patents by Inventor Yongchul Ahn
Yongchul Ahn 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: 20190221232Abstract: Magnetic sensors with effectively shaped side shields and their fabrication processes are provided. One such sensor includes a substrate, a sensor stack disposed on the substrate and having a stripe height, where the sensor stack further includes a front edge disposed at an air bearing surface (ABS) of the magnetic sensor, a back edge opposite of the front edge, and two side edges, and a side shield adjacent to each of the two side edges of the sensor stack, each side shield having a side shield height defined as a distance from the ABS to a back edge of the side shields, where the side shield height is greater than the stripe height, and where substantially no residue from materials used to form the side shield are disposed at the back edge of the sensor stack.Type: ApplicationFiled: January 12, 2018Publication date: July 18, 2019Inventors: Quang Le, Yongchul Ahn, Xiaoyong Liu, Jui-Lung Li, Hongquan Jiang
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Patent number: 10311901Abstract: The present disclosure generally relates to data storage devices, and more specifically, to a magnetic media drive employing a magnetic read head. The magnetic read head includes an antiferromagnetic layer recessed from the MFS, a reference layer disposed over the antiferromagnetic layer, a free layer disposed over the reference layer, and a thermally conductive structure disposed over the reference layer. The thermally conductive structure is recessed from the MFS. The thermally conductive structure includes a first portion and a second portion. The first portion of the thermally conductive structure extends from the second portion of the thermally conductive structure towards the MFS. The first portion of the thermally conductive structure is aligned with the free layer in a stripe height direction. With the thermally conductive structure, thermal stabilization of the read head is achieved.Type: GrantFiled: May 30, 2018Date of Patent: June 4, 2019Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Quang Le, Hongquan Jiang, Yongchul Ahn, Alexander M. Zeltser
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Publication number: 20180358543Abstract: Magnetic sensors using spin Hall effect and methods for fabricating same are provided. One such magnetic sensor includes a spin Hall layer including an electrically conductive, non-magnetic material, a magnetic free layer adjacent to the spin Hall layer, a pair of push terminals configured to enable an electrical current to pass through the magnetic free layer and the spin Hall layer in a direction that is perpendicular to a plane of the free and spin Hall layers, and a pair of sensing terminals configured to sense a voltage when the electrical current passes through the magnetic free layer and the spin Hall layer, where each of the push and sensing terminals is electrically isolated from the other terminals.Type: ApplicationFiled: November 29, 2017Publication date: December 13, 2018Inventors: Quang Le, David John Seagle, Xiaoyong Liu, Daniele Mauri, Yongchul Ahn, Hongquan Jiang, Guangli Liu, David Patrick Druist, Jui-Lung Li
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Patent number: 9053721Abstract: 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: GrantFiled: May 30, 2014Date of Patent: June 9, 2015Assignee: 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
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Publication number: 20150118520Abstract: A magnetic read sensor having improved pinning and reduced area resistance. The sensor has pinned magnetic layer that extends beyond the functional stripe of the sensor to improve magnetic pinning. The free layer has a magnetic portion that extends to the functional stripe height and a non-magnetic portion that extends beyond the functional stripe height. The sensor may have an end point detection layer located between the magnetic pinned layer and the magnetic free layer.Type: ApplicationFiled: October 24, 2013Publication date: April 30, 2015Applicant: HGST Netherlands B.V.Inventors: Yongchul Ahn, Xiaozhong Dang, Cherngye Hwang, Quang Le, Simon H. Liao, Guangli Liu, Stefan Maat
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Patent number: 8907666Abstract: A scissor style magnetic sensor having a novel hard bias structure for improved magnetic biasing robustness. The sensor includes a sensor stack that includes first and second magnetic layers separated by a non-magnetic layer such as an electrically insulating barrier layer or an electrically conductive spacer layer. The first and second magnetic layers have magnetizations that are antiparallel coupled, but that are canted in a direction that is neither parallel with nor perpendicular to the air bearing surface by a magnetic bias structure. The magnetic bias structure includes a neck portion extending from the back edge of the sensor stack and having first and second sides that are aligned with first and second sides of the sensor stack. The bias structure also includes a tapered or wedged portion extending backward from the neck portion.Type: GrantFiled: September 30, 2011Date of Patent: December 9, 2014Assignee: HGST Netherlands B.V.Inventors: Quang Le, Simon H. Liao, Shuxia Wang, Guangli Liu, Yongchul Ahn
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Patent number: 8896070Abstract: The present invention is generally directed to an apparatus with embedded (bottom side) control lines for vertically stacked semiconductor elements. In accordance with various embodiments, a first semiconductor wafer is provided with a first facing surface on which a first conductive layer is formed. The first semiconductor wafer is attached to a second semiconductor wafer to form a multi-wafer structure, the second semiconductor wafer having a second facing surface on which a second conductive wafer is formed. The first conductive layer is contactingly bonded to the second conductive layer to form an embedded combined conductive layer within said structure. Portions of the combined conductive layer are removed to form a plurality of spaced apart control lines that extend in a selected length or width dimension through said structure.Type: GrantFiled: April 13, 2012Date of Patent: November 25, 2014Assignee: Seagate Technology LLCInventors: Hyung-Kyu Lee, YoungPil Kim, Peter Nicholas Manos, Maroun Khoury, Dadi Setiadi, Chulmin Jung, Hsing-Kuen Liou, Paramasiyan Kamatchi Subramanian, Yongchul Ahn, Jinyoung Kim, Antoine Khoueir
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Patent number: 8836059Abstract: The present invention generally relates to a magnetic sensor in a read head having a hard or soft bias layer that is uniform in thickness within the sensor stack. The method of making such sensor is also disclosed. The free layer stripe height is first defined, followed by defining the track width, and lastly the pinned layer stripe height is defined. The pinned layer and the hard or soft bias layer are defined in the same process step. This approach eliminates a partial hard or soft bias layer and reduces potential instability issues.Type: GrantFiled: December 21, 2012Date of Patent: September 16, 2014Assignee: HGST Netherlands B.V.Inventors: Yongchul Ahn, Xiaozhong Dang, Yimin Hsu, Quang Le, Thomas Leong, Simon Liao, Guangli Liu, Aron Pentek
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Patent number: 8797694Abstract: A magnetic read sensor having a hard bias structure that extends beyond the back edge of the sensor stack by a controlled, distance that is chosen to maximize both hard bias field and hard bias magnetic coercivity and anisotropy. The hard bias structure has a back edge that is well defined and that has a square corner at its innermost end adjacent to the sensor stack. The magnetic sensor can be constructed by a process that includes a separate making an milling process that is dedicated to defining the back edge of the hard bias structure.Type: GrantFiled: December 22, 2011Date of Patent: August 5, 2014Assignee: HGST Netherlands B.V.Inventors: Quang Le, David J. Seagle, Guangli Liu, Yongchul Ahn, Simon H. Liao
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Publication number: 20140175576Abstract: The present invention generally relates to a magnetic sensor in a read head having a hard or soft bias layer that is uniform in thickness within the sensor stack. The method of making such sensor is also disclosed. The free layer stripe height is first defined, followed by defining the track width, and lastly the pinned layer stripe height is defined. The pinned layer and the hard or soft bias layer are defined in the same process step. This approach eliminates a partial hard or soft bias layer and reduces potential instability issues.Type: ApplicationFiled: December 21, 2012Publication date: June 26, 2014Applicant: HGST Netherlands B.V.Inventors: Yongchul AHN, Xiaozhong DANG, Yimin HSU, Quang LE, Thomas LEONG, Simon LIAO, Guangli LIU, Aron PENTEK
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Patent number: 8686388Abstract: A resistive sense memory cell includes a layer of crystalline praseodymium calcium manganese oxide and a layer of amorphous praseodymium calcium manganese oxide disposed on the layer of crystalline praseodymium calcium manganese oxide forming a resistive sense memory stack. A first and second electrode are separated by the resistive sense memory stack. The resistive sense memory cell can further include an oxygen diffusion barrier layer separating the layer of crystalline praseodymium calcium manganese oxide from the layer of amorphous praseodymium calcium manganese oxide a layer. Methods include depositing an amorphous praseodymium calcium manganese oxide disposed on the layer of crystalline praseodymium calcium manganese oxide forming a resistive sense memory stack.Type: GrantFiled: July 12, 2012Date of Patent: April 1, 2014Assignee: Seagater Technology LLCInventors: Andreas Roelofs, Markus Siegert, Venugopalan Vaithyanathan, Wei Tian, Yongchul Ahn, Muralikrishnan Balakrishnan, Olle Heinonen
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Patent number: 8615868Abstract: A method for manufacturing a magnetic sensor that includes depositing a plurality of mask layers, then forming a stripe height defining mask over the sensor layers. A first ion milling is performed just sufficiently to remove portions of the free layer that are not protected by the stripe height defining mask, the first ion milling being terminated at the non-magnetic barrier or spacer layer. A dielectric layer is then deposited, preferably by ion beam deposition. A second ion milling is then performed to remove portions of the pinned layer structure that are not protected by the mask, the free layer being protected during the second ion milling by the dielectric layer.Type: GrantFiled: November 29, 2011Date of Patent: December 31, 2013Assignee: HGST Netherlands B.V.Inventors: Yongchul Ahn, Xiaozhong Dang, Quang Le, Simon H. Liao
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Publication number: 20130163121Abstract: A magnetic read sensor having a hard bias structure that extends beyond the back edge of the sensor stack by a controlled, distance that is chosen to maximize both hard bias field and hard bias magnetic coercivity and anisotropy. The hard bias structure has a back edge that is well defined and that has a square corner at its innermost end adjacent to the sensor stack. The magnetic sensor can be constructed by a process that includes a separate making an milling process that is dedicated to defining the back edge of the hard bias structure.Type: ApplicationFiled: December 22, 2011Publication date: June 27, 2013Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Quang Le, David J. Seagle, Guangli Liu, Yongchul Ahn, Simon H. Liao
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Publication number: 20130135772Abstract: A method for manufacturing a magnetic sensor that includes depositing a plurality of mask layers, then forming a stripe height defining mask over the sensor layers. A first ion milling is performed just sufficiently to remove portions of the free layer that are not protected by the stripe height defining mask, the first ion milling being terminated at the non-magnetic barrier or spacer layer. A dielectric layer is then deposited, preferably by ion beam deposition. A second ion milling is then performed to remove portions of the pinned layer structure that are not protected by the mask, the free layer being protected during the second ion milling by the dielectric layer.Type: ApplicationFiled: November 29, 2011Publication date: May 30, 2013Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Yongchul Ahn, Xiaozhong Dang, Quang Le, Simon H. Liao
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Publication number: 20130083432Abstract: A magnetic read head having a hard bias structure that both optimizes magnetic bias field and also ensures manufacturability while maintaining sensor stripe height integrity. The read head includes a sensor stack having a back edge and first and second laterally opposed sides. A hard bias structure extending from each of the first and second sides of the sensor stack has a neck portion located near the sensor and having a back edge that is aligned with and parallel to the back edge of the sensor stack. The hard bias structure also includes a flared portion having a back edge that defines an angle relative to the air bearing surface of the read head. The back edge preferably defines and angle of 45-75 degrees relative to the air bearing surface.Type: ApplicationFiled: September 29, 2011Publication date: April 4, 2013Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Quang Le, Simon H. Liao, Shuxia Wang, Guangli Liu, Yongchul Ahn
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Publication number: 20130082696Abstract: A scissor style magnetic sensor having a novel hard bias structure for improved magnetic biasing robustness. The sensor includes a sensor stack that includes first and second magnetic layers separated by a non-magnetic layer such as an electrically insulating barrier layer or an electrically conductive spacer layer. The first and second magnetic layers have magnetizations that are antiparallel coupled, but that are canted in a direction that is neither parallel with nor perpendicular to the air bearing surface by a magnetic bias stricture. The magnetic bias structure includes a neck portion extending from the back edge of the sensor stack and having first and second sides that are aligned with first and second sides of the sensor stack. The bias structure also includes a tapered or wedged portion extending backward from the neck portion.Type: ApplicationFiled: September 30, 2011Publication date: April 4, 2013Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Quang Le, Simon H. Liao, Shuxia Wang, Guangli Liu, Yongchul Ahn
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Publication number: 20120273744Abstract: A resistive sense memory cell includes a layer of crystalline praseodymium calcium manganese oxide and a layer of amorphous praseodymium calcium manganese oxide disposed on the layer of crystalline praseodymium calcium manganese oxide forming a resistive sense memory stack. A first and second electrode are separated by the resistive sense memory stack. The resistive sense memory cell can further include an oxygen diffusion barrier layer separating the layer of crystalline praseodymium calcium manganese oxide from the layer of amorphous praseodymium calcium manganese oxide a layer. Methods include depositing an amorphous praseodymium calcium manganese oxide disposed on the layer of crystalline praseodymium calcium manganese oxide forming a resistive sense memory stack.Type: ApplicationFiled: July 12, 2012Publication date: November 1, 2012Applicant: SEAGATE TECHNOLOGY LLCInventors: Andreas Roelofs, Markus Siegert, Venugopalan Vaithyanathan, Wei Tian, Yongchul Ahn, Muralikrishnan Balakrishnan, Olle Heinonen
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Publication number: 20120231296Abstract: A method for manufacturing a magnetic sensor that minimizes topography resulting from stripe height defining masking and patterning in order to facilitate definition of track width. The method includes depositing a series of mask layers and then masking and ion milling the series of sensor layers to define a back edge of a sensor. A non-magnetic fill layer is then deposited, the magnetic fill layer being constructed of a material that has an ion mill rate that is similar to that of the series of sensor layers. A second masking and milling process is then performed to define the track width of the sensor and hard bias is deposited. Because the non-magnetic fill layer is removed at substantially the same rate as the sensor material the structure has a very flat topography on which to form the sensor track width.Type: ApplicationFiled: March 11, 2011Publication date: September 13, 2012Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Quang Le, Jui-Lung Li, Yongchul Ahn, Simon H. Liao, Guangli Liu, Masaya Nishioka
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Publication number: 20120199915Abstract: The present invention is generally directed to an apparatus with embedded (bottom side) control lines for vertically stacked semiconductor elements. In accordance with various embodiments, a first semiconductor wafer is provided with a first facing surface on which a first conductive layer is formed. The first semiconductor wafer is attached to a second semiconductor wafer to form a multi-wafer structure, the second semiconductor wafer having a second facing surface on which a second conductive wafer is formed. The first conductive layer is contactingly bonded to the second conductive layer to form an embedded combined conductive layer within said structure. Portions of the combined conductive layer are removed to form a plurality of spaced apart control lines that extend in a selected length or width dimension through said structure.Type: ApplicationFiled: April 13, 2012Publication date: August 9, 2012Applicant: Seagate Technology LLCInventors: Hyung-Kyu Lee, YoungPil Kim, Peter Nicholas Manos, Maroun Khoury, Dadi Setiadi, Chulmin Jung, Hsing-Kuen Liou, Paramasiyan Kamatchi Subramanian, Yongchul Ahn, Jinyoung Kim, Antoine Khoueir
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Patent number: 8227783Abstract: A resistive sense memory cell includes a layer of crystalline praseodymium calcium manganese oxide and a layer of amorphous praseodymium calcium manganese oxide disposed on the layer of crystalline praseodymium calcium manganese oxide forming a resistive sense memory stack. A first and second electrode are separated by the resistive sense memory stack. The resistive sense memory cell can further include an oxygen diffusion barrier layer separating the layer of crystalline praseodymium calcium manganese oxide from the layer of amorphous praseodymium calcium manganese oxide a layer. Methods include depositing an amorphous praseodymium calcium manganese oxide disposed on the layer of crystalline praseodymium calcium manganese oxide forming a resistive sense memory stack.Type: GrantFiled: July 13, 2009Date of Patent: July 24, 2012Assignee: Seagate Technology LLCInventors: Andreas Roelofs, Markus Siegert, Venugopalan Vaithyanathan, Wei Tian, Yongchul Ahn, Muralikrishnan Balakrishnan, Olle Heinonen