Patents by Inventor Tsann Lin
Tsann Lin 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: 20190067564Abstract: The disclosed technology generally relates to magnetic memory devices, and more particularly to spin transfer torque magnetic random access memory (STT-MRAM) devices having a magnetic tunnel junction (MTJ), and further relates to methods of fabricating the STT-MRAM devices. In an aspect, a magnetoresistive random access memory (MRAM) device has a magnetic tunnel junction (MTJ). The MTJ includes a magnetic reference layer comprising CoFeB, a magnetic free layer comprising CoFeB, and a barrier layer comprising MgO. The barrier layer is interposed between the magnetic reference layer and the magnetic free layer. The barrier layer has a thickness adapted to tunnel electrons between the magnetic reference layer and the magnetic free layer sufficient to cause a change in the magnetization direction of the variable magnetization under a bias. The MTJ further comprises a buffer layer comprising one or more of Co, Fe, CoFe and CoFeB, where the buffer layer is doped with one or both of C and N.Type: ApplicationFiled: August 13, 2018Publication date: February 28, 2019Inventors: Johan Swerts, Kiroubanand Sankaran, Tsann Lin, Geoffrey Pourtois
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Patent number: 10050192Abstract: The disclosed technology generally relates to magnetic memory devices, and more particularly to spin transfer torque magnetic random access memory (STT-MRAM) devices having a magnetic tunnel junction (MTJ), and further relates to methods of fabricating the STT-MRAM devices. In an aspect, a magnetoresistive random access memory (MRAM) device has a magnetic tunnel junction (MTJ). The MTJ includes a magnetic reference layer including CoFeB, a magnetic free layer comprising CoFeB, and a barrier layer including MgO. The barrier layer is interposed between the magnetic reference layer and the magnetic free layer. The barrier layer has a thickness adapted to tunnel electrons between the magnetic reference layer and the magnetic free layer sufficient to cause a change in the magnetization direction of the variable magnetization under a bias. The MTJ further comprises a buffer layer comprising one or more of Co, Fe, CoFe and CoFeB, where the buffer layer is doped with one or both of C and N.Type: GrantFiled: December 8, 2016Date of Patent: August 14, 2018Assignee: IMEC vzwInventors: Johan Swerts, Kiroubanand Sankaran, Tsann Lin, Geoffrey Pourtois
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Publication number: 20170170390Abstract: The disclosed technology generally relates to magnetic memory devices, and more particularly to spin transfer torque magnetic random access memory (STT-MRAM) devices having a magnetic tunnel junction (MTJ), and further relates to methods of fabricating the STT-MRAM devices. In an aspect, a magnetoresistive random access memory (MRAM) device has a magnetic tunnel junction (MTJ). The MTJ includes a magnetic reference layer comprising CoFeB, a magnetic free layer comprising CoFeB, and a barrier layer comprising MgO. The barrier layer is interposed between the magnetic reference layer and the magnetic free layer. The barrier layer has a thickness adapted to tunnel electrons between the magnetic reference layer and the magnetic free layer sufficient to cause a change in the magnetization direction of the variable magnetization under a bias. The MTJ further comprises a buffer layer comprising one or more of Co, Fe, CoFe and CoFeB, where the buffer layer is doped with one or both of C and N.Type: ApplicationFiled: December 8, 2016Publication date: June 15, 2017Inventors: Johan Swerts, Kiroubanand Sankaran, Tsann Lin, Geoffrey Pourtois
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Patent number: 8947835Abstract: The invention provides a tunneling magnetoresistance (TMR) read sensor with a long diffusion path and ex-situ interfaces in a sense layer structure. The sense layer structure comprises a first sense layer preferably formed of a ferromagnetic Co—Fe film, a second sense layer preferably formed of a ferromagnetic Co—Fe—B film, and a third sense layer preferably formed of a ferromagnetic Ni—Fe film. The sense layer structure has a long diffusion path (defined as a total thickness of the first and second sense layers) and ex-situ interfaces for suppressing unwanted diffusions of Ni atoms. Alternatively, the sense layer structure comprises a first sense layer preferably formed of a ferromagnetic Co—Fe film, a second sense layer preferably formed of a ferromagnetic Co—Fe—B film, a third sense layer preferably formed of a ferromagnetic Co—Fe—B—Hf film, and a fourth sense layer preferably formed of a ferromagnetic Ni—Fe film.Type: GrantFiled: December 22, 2011Date of Patent: February 3, 2015Assignee: HGST Netherlands B.V.Inventor: Tsann Lin
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Patent number: 8946707Abstract: The invention provides a tunneling magnetoresistance (TMR) read sensor with an integrated auxiliary shield comprising buffer, parallel-coupling, shielding and decoupling layers for high-resolution magnetic recording. The buffer layer, preferably formed of an amorphous ferromagnetic Co—X (where X is Hf, Y, Zr, etc.) film, creates microstructural discontinuity between a lower ferromagnetic shield and the TMR read sensor. The parallel-coupling layer, preferably formed of a polycrystalline nonmagnetic Ru film, causes parallel coupling between the buffer and shielding layers. The shielding layer, preferably formed of a polycrystalline ferromagnetic Ni—Fe film exactly identical to that used as the lower ferromagnetic shield, shields magnetic fluxes stemming from a recording medium into the lower edge of the TMR read sensor.Type: GrantFiled: January 30, 2013Date of Patent: February 3, 2015Assignee: HGST Netherlands B.V.Inventor: Tsann Lin
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Patent number: 8836000Abstract: The invention provides a bottom-type perpendicular magnetic tunnel junction (pMTJ) element with thermally stable amorphous blocking layers for high-density nonvolatile data storage. The first blocking layer, preferably formed of an amorphous nonmagnetic film, blocks a polycrystalline diffusion barrier layer with a body-center-cubic (bcc) <110> texture in order for the keeper and lower reference layers of the bottom-type pMTJ element to freely grow with a face-centered-cubic (fcc) <111> texture, thereby developing strong perpendicular magnetic anisotropy (PMA). The second blocking layer, preferably formed of an amorphous ferromagnetic film, blocks the keeper and lower reference layers of the bottom-type pMTJ element in order for the upper reference, barrier and storage layers of the bottom-type pMTJ element to freely grow with a <001> texture, thereby exhibiting a strong tunneling magnetoresistance (TMR) effect.Type: GrantFiled: May 10, 2013Date of Patent: September 16, 2014Assignee: Avalanche Technology, Inc.Inventor: Tsann Lin
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Publication number: 20140210024Abstract: The invention provides a tunneling magnetoresistance (TMR) read sensor with an integrated auxiliary shield comprising buffer, parallel-coupling, shielding and decoupling layers for high-resolution magnetic recording. The buffer layer, preferably formed of an amorphous ferromagnetic Co—X (where X is Hf, Y, Zr, etc.) film, creates microstructural discontinuity between a lower ferromagnetic shield and the TMR read sensor. The parallel-coupling layer, preferably formed of a polycrystalline nonmagnetic Ru film, causes parallel coupling between the buffer and shielding layers. The shielding layer, preferably formed of a polycrystalline ferromagnetic Ni—Fe film exactly identical to that used as the lower ferromagnetic shield, shields magnetic fluxes stemming from a recording medium into the lower edge of the TMR read sensor.Type: ApplicationFiled: January 30, 2013Publication date: July 31, 2014Applicant: HGST NETHERLANDS B.V.Inventor: Tsann Lin
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Patent number: 8675317Abstract: A current-perpendicular-to-plane (CPP) tunneling magnetoresistance (TMR) or giant magnetoresistance (GMR) read sensor with dual seed and cap layers for high-resolution magnetic recording is provided by the invention. The dual seed layers comprise a lower seed layer preferably formed of a nonmagnetic Pt film and an upper seed layer preferably formed of a nonmagnetic Ru film. The lower seed layer separates the upper seed layer from a buffer layer preferably formed of a ferromagnetic Co—Hf film, in order to minimize moment losses at its lower interface and thus define a sharp lower bound of a read gap. In addition, the lower seed layer facilitates the CPP read sensor to exhibit high pinning properties, while the upper seed layer facilitates the CPP read sensor to exhibit robust thermal properties.Type: GrantFiled: December 22, 2010Date of Patent: March 18, 2014Assignee: HGST Netherlands B.V.Inventor: Tsann Lin
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Publication number: 20140004383Abstract: A current-perpendicular-to-plane (CPP) read sensor with Co—Fe buffer layers is proposed to improve pinning and magnetoresistance properties. The read sensor comprises first and second Co—Fe buffer layers in the lower and upper portions of a keeper layer structure, respectively, third and fourth Co—Fe buffer layers in the lower and upper portion of a reference layer structure, respectively, and a fifth Co—Fe buffer layer in the lower portion of a sense layer structure. The first buffer layer is adjacent to a pinning layer and has a specific composition to improve unidirectional-anisotropy pinning properties. The second and third buffer layers are adjacent to an antiparallel-coupling layer and have specific compositions to improve bidirectional-anisotropy pinning properties. The fourth and fifth buffer layers are adjacent to a barrier or spacer layer and have specific compositions to improve magnetoresistance properties.Type: ApplicationFiled: August 30, 2013Publication date: January 2, 2014Applicant: HGST Netherlands B.V.Inventor: Tsann Lin
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Patent number: 8610584Abstract: A fall-down alarm system includes a contact detection unit, a non-contact detection unit and a fall-down evaluation unit connecting respectively to the contact detection unit and non-contact detection unit. The contact detection unit and non-contact detection unit respectively detect an abnormal detected shape of an object and abnormal life symptoms of the object, and then the fall-down evaluation unit determines a fall-down condition and sends a trigger signal to request assistance. Through the contact detection unit and non-contact detection unit respectively detecting the shape and life symptoms of the object, the erroneous fall-down judgment can be reduced.Type: GrantFiled: July 20, 2011Date of Patent: December 17, 2013Assignee: China Medical UniversityInventors: Jin-Chern Chiou, Tsann Lin, Shih-Che Lo, Jeng-Ren Duann, Sheng-Chuan Liang, Yung-Jiun Lin
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Patent number: 8553370Abstract: The present invention generally relates to a TMR reader and a method for its manufacture. The TMR reader discussed herein adds a shield layer to the sensor structure. The shield layer is deposited over the capping layer so that the shield layer and the capping layer collectively protect the free magnetic layer within the sensor structure from damage during further processing. Additionally, the hard bias layer is shaped such that the entire hard bias layer underlies the hard bias capping layer so that a top lead layer is not present. By eliminating the top lead layer and including a shield layer within the sensor structure, the read gap is reduced while still protecting the free magnetic layer during later processing.Type: GrantFiled: November 24, 2010Date of Patent: October 8, 2013Assignee: HGST Netherlands B.V.Inventors: Liubo Hong, Honglin Zhu, Tsann Lin, Zheng Gao
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Patent number: 8537504Abstract: A current-perpendicular-to-plane (CPP) tunneling magnetoresistance (TMR) or giant magnetoresistance (GMR) read sensor with ferromagnetic buffer, shielding and seed layers is proposed for high-resolution magnetic recording. The ferromagnetic buffer layer is preferably formed of an amorphous Co—X (where X is Hf, Y, Zr, etc.) film. It provides the CPP read sensor with microstructural discontinuity from a ferromagnetic lower shield, thus facilitating the CPP read sensor to grow freely with preferred crystalline textures, and with ferromagnetic continuity to the ferromagnetic lower shield, thus acting as a portion of the ferromagnetic lower shield. The ferromagnetic shielding layer is preferably formed of a polycrystalline Ni—Fe film. It exhibits magnetic properties exactly identical to those of the ferromagnetic lower shield, thus acting identically as the ferromagnetic lower shield, and a uniform columnar grain morphology, thus initiating a uniform large grain morphology in the CPP read sensor.Type: GrantFiled: September 16, 2010Date of Patent: September 17, 2013Assignee: HGST Netherlands B.V.Inventor: Tsann Lin
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Publication number: 20130164562Abstract: The invention provides a tunneling magnetoresistance (TMR) read sensor with a long diffusion path and ex-situ interfaces in a sense layer structure. The sense layer structure comprises a first sense layer preferably formed of a ferromagnetic Co—Fe film, a second sense layer preferably formed of a ferromagnetic Co—Fe—B film, and a third sense layer preferably formed of a ferromagnetic Ni—Fe film. The sense layer structure has a long diffusion path (defined as a total thickness of the first and second sense layers) and ex-situ interfaces for suppressing unwanted diffusions of Ni atoms. Alternatively, the sense layer structure comprises a first sense layer preferably formed of a ferromagnetic Co—Fe film, a second sense layer preferably formed of a ferromagnetic Co—Fe—B film, a third sense layer preferably formed of a ferromagnetic Co—Fe—B—Hf film, and a fourth sense layer preferably formed of a ferromagnetic Ni—Fe film.Type: ApplicationFiled: December 22, 2011Publication date: June 27, 2013Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventor: Tsann Lin
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Patent number: 8451566Abstract: A current-perpendicular-to-plane (CPP) tunneling magnetoresistance (TMR) or giant magnetoresistance (GMR) read sensor with ferromagnetic buffer and seed layers is proposed for high-resolution magnetic recording. The ferromagnetic buffer layer is preferably formed of an amorphous Co—X (where X is Hf, Y, Zr, etc.) film. It provides the CPP read sensor with microstructural discontinuity from a ferromagnetic lower shield, thus facilitating the CPP read sensor to grow freely with preferred crystalline textures, and with ferromagnetic continuity to the ferromagnetic lower shield, thus acting as a portion of the ferromagnetic lower shield.Type: GrantFiled: September 16, 2010Date of Patent: May 28, 2013Assignee: HGST Netherlands B.V.Inventor: Tsann Lin
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Patent number: 8325450Abstract: A magnetic structure in one embodiment includes a tunnel barrier layer; a free layer; and a buffer layer between the tunnel barrier layer and the free layer, wherein a cross sectional area of the tunnel barrier layer in a direction parallel to a plane of deposition thereof is greater than a cross sectional area of the free layer in a direction parallel to a plane of deposition thereof, wherein a cross sectional area of the buffer layer in a direction parallel to a plane of deposition thereof is greater than a cross sectional area of the free layer in the direction parallel to the plane of deposition thereof. Additional systems and methods are also presented.Type: GrantFiled: December 10, 2008Date of Patent: December 4, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Ying Hong, Kochan Ju, Tsann Lin, Ching Hwa Tsang
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Publication number: 20120299132Abstract: The invention provides a TMR read sensor with low-contact-resistance metal/metal, metal/oxide and oxide/metal interfaces. The low-contact-resistance metal/metal interfaces in a reference or sense layer structure are in-situ formed in a high-vacuum deposition module of a sputtering system, without exposures to low vacuum in a transfer module and damages caused by a plasma treatment conducted in an etching module. The low-contact-resistance metal/oxide interface is formed by utilizing a thin Co—Fe—B reference layer and a thick Co—Fe reference layer to reduce boron diffusion and segregation caused by annealing. The low-contact-resistance oxide/metal interface is formed by replacing a Co—Fe—B sense layer with a Co-rich Co—Fe sense layer to eliminate boron diffusion and segregation caused by annealing. With the low-contact-resistance metal/metal, metal/oxide and oxide/metal interfaces, the TMR read sensor exhibits a junction resistance-area product of below 0.Type: ApplicationFiled: May 27, 2011Publication date: November 29, 2012Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventor: Tsann Lin
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Patent number: 8274762Abstract: A system in one approach includes a sensor stack formed of a plurality of thin film layers; a shunt formed of at least some of the same layers as the sensor stack, the shunt being spaced from the sensor stack; a first lead coupled to the sensor stack and the shunt; and a second lead coupled to the sensor stack and the shunt. A method in one embodiment includes forming a plurality of thin film layers; removing a portion of the thin film layers for defining at least a portion of a sensor stack and at least a portion of a shunt spaced front the sensor stack; forming a first lead coupled to the at least a portion of the sensor stack and the at least a portion of the shunt and a second lead coupled to the at least a portion of the sensor stack and the at least a portion of the shunt. Additional systems and methods are also presented.Type: GrantFiled: May 30, 2008Date of Patent: September 25, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Satoru Araki, Ying Hong, Edward Hin Pong Lee, Tsann Lin, David John Seagle
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Patent number: 8243401Abstract: A tunneling magnetoresistance (TMR) read sensor with a Co—Fe—B lower sense layer and a Co—Hf upper sense layer is disclosed. In order for the dual sense layers to exhibit a negative saturation magnetostriction (?S), their Fe contents are either substantially reduced or even eliminated, instead of adding a conventional Ni—Fe film as an additional sense layer. By optimizing compositions and thicknesses of the dual sense layers, the dual sense layers indeed exhibit a negative ?S, while the TMR sensor exhibits a TMR coefficient (?RT/RJ) of greater than 80% at a junction resistance-area product (RJAJ) of less than 2 ?-?m2.Type: GrantFiled: October 2, 2009Date of Patent: August 14, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventor: Tsann Lin
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Patent number: 8213132Abstract: A narrow track-width magnetoresistive sensor by defining a trench formed between first and second hard bias layers and depositing the sensor into the trench. The sensor can include a sensor stack sandwiched between first and second electrically conductive lead layers. First and second electrically insulating side walls are formed at either side of the sensor stack. First and second hard bias layers extend from the sides of the sensor stack, being separated from the sensor stack by the first and second electrically insulating side walls. First and second physically hard insulation layers are provided over each of the hard bias layers.Type: GrantFiled: November 12, 2007Date of Patent: July 3, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: David Eugene Heim, Kim Y. Lee, Tsann Lin, Jih-Shiuan Luo
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Publication number: 20120164485Abstract: A current-perpendicular-to-plane (CPP) tunneling magnetoresistance (TMR) or giant magnetoresistance (GMR) read sensor with dual seed and cap layers for high-resolution magnetic recording is provided by the invention. The dual seed layers comprise a lower seed layer preferably formed of a nonmagnetic Pt film and an upper seed layer preferably formed of a nonmagnetic Ru film. The lower seed layer separates the upper seed layer from a buffer layer preferably formed of a ferromagnetic Co—Hf film, in order to minimize moment losses at its lower interface and thus define a sharp lower bound of a read gap. In addition, the lower seed layer facilitates the CPP read sensor to exhibit high pinning properties, while the upper seed layer facilitates the CPP read sensor to exhibit robust thermal properties.Type: ApplicationFiled: December 22, 2010Publication date: June 28, 2012Applicant: Hitachi Global Strorage Technologies Netherland B.V.Inventor: Tsann Lin