Patents by Inventor Zhitao Diao
Zhitao Diao 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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Patent number: 11776725Abstract: A magnetic element includes a first free layer, a barrier layer over the first free layer, and a second free layer over the barrier layer. The first free layer includes a first ferromagnetic bilayer and a first amorphous insertion layer (e.g., CoHf) between the first ferromagnetic bilayer. The first ferromagnetic bilayer is selected from CoB, CoFeB, FeB, and combinations thereof. The second free layer includes a second ferromagnetic bilayer and a second amorphous insertion layer (e.g., CoHf) between the second ferromagnetic bilayer. The second ferromagnetic bilayer is selected from CoB, CoFeB, FeB, and combinations thereof. Each of the first and the second amorphous insertion layer independently can be ferromagnetic or non-ferromagnetic and can have a recrystallization temperature of about 300° C. and above. The magnetic element can further include a non-ferromagnetic amorphous buffer layer and/or a non-ferromagnetic amorphous capping layer.Type: GrantFiled: August 1, 2022Date of Patent: October 3, 2023Assignee: Western Digital Technologies, Inc.Inventors: Zhitao Diao, Christian Kaiser, Yuankai Zheng
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Patent number: 11598828Abstract: The present disclosure generally relates to a Wheatstone bridge array that has four resistors. Each resistor includes a plurality of TMR structures. Two resistors have identical TMR structures. The remaining two resistors also have identical TMR structures, though the TMR structures are different from the other two resistors. Additionally, the two resistors that have identical TMR structures have a different resistance area as compared to the remaining two resistors that have identical TMR structures. Therefore, the working bias field for the Wheatstone bridge array is non-zero.Type: GrantFiled: December 30, 2019Date of Patent: March 7, 2023Assignee: Western Digital Technologies, Inc.Inventors: Yuankai Zheng, Christian Kaiser, Zhitao Diao, Chih-Ching Hu, Chen-jung Chien, Yung-Hung Wang, Dujiang Wan, Ronghui Zhou, Ming Mao, Ming Jiang, Daniele Mauri
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Publication number: 20220367099Abstract: A magnetic element includes a first free layer, a barrier layer over the first free layer, and a second free layer over the barrier layer. The first free layer includes a first ferromagnetic bilayer and a first amorphous insertion layer (e.g., CoHf) between the first ferromagnetic bilayer. The first ferromagnetic bilayer is selected from CoB, CoFeB, FeB, and combinations thereof. The second free layer includes a second ferromagnetic bilayer and a second amorphous insertion layer (e.g., CoHf) between the second ferromagnetic bilayer. The second ferromagnetic bilayer is selected from CoB, CoFeB, FeB, and combinations thereof. Each of the first and the second amorphous insertion layer independently can be ferromagnetic or non-ferromagnetic and can have a recrystallization temperature of about 300° C. and above. The magnetic element can further include a non-ferromagnetic amorphous buffer layer and/or a non-ferromagnetic amorphous capping layer.Type: ApplicationFiled: August 1, 2022Publication date: November 17, 2022Applicant: Western Digital Technologies, Inc.Inventors: Zhitao DIAO, Christian KAISER, Yuankai ZHENG
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Patent number: 11430592Abstract: A magnetic element includes a first free layer, a barrier layer over the first free layer, and a second free layer over the barrier layer. The first free layer includes a first ferromagnetic bilayer and a first amorphous insertion layer (e.g., CoHf) between the first ferromagnetic bilayer. The first ferromagnetic bilayer is selected from CoB, CoFeB, FeB, and combinations thereof. The second free layer includes a second ferromagnetic bilayer and a second amorphous insertion layer (e.g., CoHf) between the second ferromagnetic bilayer. The second ferromagnetic bilayer is selected from CoB, CoFeB, FeB, and combinations thereof. Each of the first and the second amorphous insertion layer independently can be ferromagnetic or non-ferromagnetic and can have a recrystallization temperature of about 300° C. and above. The magnetic element can further include a non-ferromagnetic amorphous buffer layer and/or a non-ferromagnetic amorphous capping layer.Type: GrantFiled: February 25, 2021Date of Patent: August 30, 2022Assignee: Western Digital Technologies, Inc.Inventors: Zhitao Diao, Christian Kaiser, Yuankai Zheng
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Patent number: 11415645Abstract: The present disclosure generally relates to a Wheatstone bridge array comprising TMR sensors and a method of fabrication thereof. In the Wheatstone bridge array, there are four distinct TMR sensors. The TMR sensors are all fabricated simultaneously to create four identical TMR sensors that have synthetic antiferromagnetic free layers as the top layer. The synthetic antiferromagnetic free layers comprise a first magnetic layer, a spacer layer, and a second magnetic layer. After forming the four identical TMR sensors, the spacer layer and the second magnetic layer are removed from two TMR sensors. Following the removal of the spacer layer and the second magnetic layer, a new magnetic layer is formed on the now exposed first magnetic layer such that the new magnetic layer has substantially the same thickness as the spacer layer and second magnetic layer combined.Type: GrantFiled: December 30, 2019Date of Patent: August 16, 2022Assignee: Western Digital Technologies, Inc.Inventors: Yuankai Zheng, Christian Kaiser, Zhitao Diao, Chih-Ching Hu, Chen-jung Chien, Yung-Hung Wang, Ming Mao, Ming Jiang
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Patent number: 11385305Abstract: A tunneling magnetoresistance (TMR) sensor device is disclosed that includes one or more TMR sensors. The TMR sensor device comprises a first resistor comprising a first TMR film, a second resistor comprising a second TMR film different than the first TMR film, a third resistor comprising the second TMR film, and a fourth resistor comprising the first TMR film. The first TMR film comprises a reference layer having a first magnetization direction anti-parallel to a second magnetization direction of a pinned layer. The second TMR film comprises a reference layer having a first magnetization direction parallel to a second magnetization direction of a first pinned layer, and a second pinned layer having a third magnetization direction anti-parallel to the first magnetization direction of the reference layer and the second magnetization direction of the first pinned layer.Type: GrantFiled: December 18, 2019Date of Patent: July 12, 2022Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Yuankai Zheng, Christian Kaiser, Zhitao Diao, Chih-Ching Hu, Chen-Jung Chien, Yung-Hung Wang, Dujiang Wan, Ronghui Zhou, Ming Mao, Ming Jiang, Daniele Mauri
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Publication number: 20220093305Abstract: A magnetic element includes a first free layer, a barrier layer over the first free layer, and a second free layer over the barrier layer. The first free layer includes a first ferromagnetic bilayer and a first amorphous insertion layer (e.g., CoHf) between the first ferromagnetic bilayer. The first ferromagnetic bilayer is selected from CoB, CoFeB, FeB, and combinations thereof. The second free layer includes a second ferromagnetic bilayer and a second amorphous insertion layer (e.g., CoHf) between the second ferromagnetic bilayer. The second ferromagnetic bilayer is selected from CoB, CoFeB, FeB, and combinations thereof. Each of the first and the second amorphous insertion layer independently can be ferromagnetic or non-ferromagnetic and can have a recrystallization temperature of about 300° C. and above. The magnetic element can further include a non-ferromagnetic amorphous buffer layer and/or a non-ferromagnetic amorphous capping layer.Type: ApplicationFiled: February 25, 2021Publication date: March 24, 2022Inventors: Zhitao DIAO, Christian KAISER, Yuankai ZHENG
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Patent number: 11211083Abstract: Embodiments of the present disclosure generally relate to a write head for a magnetic recording device. The write head includes a spin torque oscillator (STO) that has a seed layer formed on a write pole, a spin polarization layer (SPL) formed on the seed layer, a first spacer layer formed on the SPL, a field generation layer (FGL) formed on the first spacer layer, a second spacer layer formed on the FGL, and a notch formed on the second spacer layer. The FGL and the notch are antiferromagnetically coupled through the second spacer layer and thus increases the FGL angle and improves the write capabilities of the write head.Type: GrantFiled: June 24, 2020Date of Patent: December 28, 2021Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Yuankai Zheng, Zheng Gao, Christian Kaiser, Zhitao Diao, Susumu Okamura, James Mac Freitag, Alexander Goncharov
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Patent number: 11125840Abstract: The present disclosure generally relates to a tunnel magnetoresistive (TMR) device. The TMR device includes a high radiation reflective layer between the bottom shield of the TMR device and the magnetic seed layer. The high radiation reflective layer helps to maintain the TMR device temperature during transportation between processing chambers. Additionally, the high radiation reflective layer decreases the resistance area (RA) of the TMR device while also increasing the magnetoresistance (MR) of the TMR device.Type: GrantFiled: February 18, 2020Date of Patent: September 21, 2021Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Yuankai Zheng, Christian Kaiser, Zhitao Diao
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Publication number: 20210255256Abstract: The present disclosure generally relates to a tunnel magnetoresistive (TMR) device. The TMR device includes a high radiation reflective layer between the bottom shield of the TMR device and the magnetic seed layer. The high radiation reflective layer helps to maintain the TMR device temperature during transportation between processing chambers. Additionally, the high radiation reflective layer decreases the resistance area (RA) of the TMR device while also increasing the magnetoresistance (MR) of the TMR device.Type: ApplicationFiled: February 18, 2020Publication date: August 19, 2021Inventors: Yuankai ZHENG, Christian KAISER, Zhitao DIAO
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Publication number: 20210063507Abstract: The present disclosure generally relates to a Wheatstone bridge array that has four resistors. Each resistor includes a plurality of TMR structures. Two resistors have identical TMR structures. The remaining two resistors also have identical TMR structures, though the TMR structures are different from the other two resistors. Additionally, the two resistors that have identical TMR structures have a different resistance area as compared to the remaining two resistors that have identical TMR structures. Therefore, the working bias field for the Wheatstone bridge array is non-zero.Type: ApplicationFiled: December 30, 2019Publication date: March 4, 2021Inventors: Yuankai ZHENG, Christian KAISER, Zhitao DIAO, Chih-Ching HU, Chen-jung CHIEN, Yung-Hung WANG, Dujiang WAN, Ronghui ZHOU, Ming MAO, Ming JIANG, Daniele MAURI
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Publication number: 20210063504Abstract: A tunneling magnetoresistance (TMR) sensor device is disclosed that includes one or more TMR sensors. The TMR sensor device comprises a first resistor comprising a first TMR film, a second resistor comprising a second TMR film different than the first TMR film, a third resistor comprising the second TMR film, and a fourth resistor comprising the first TMR film. The first TMR film comprises a reference layer having a first magnetization direction anti-parallel to a second magnetization direction of a pinned layer. The second TMR film comprises a reference layer having a first magnetization direction parallel to a second magnetization direction of a first pinned layer, and a second pinned layer having a third magnetization direction anti-parallel to the first magnetization direction of the reference layer and the second magnetization direction of the first pinned layer.Type: ApplicationFiled: December 18, 2019Publication date: March 4, 2021Inventors: Yuankai ZHENG, Christian KAISER, Zhitao DIAO, Chih-Ching HU, Chen-Jung CHIEN, Yung-Hung WANG, Dujiang WAN, Ronghui ZHOU, Ming MAO, Ming JIANG, Daniele MAURI
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Publication number: 20210055361Abstract: The present disclosure generally relates to a Wheatstone bridge array comprising TMR sensors and a method of fabrication thereof. In the Wheatstone bridge array, there are four distinct TMR sensors. The TMR sensors are all fabricated simultaneously to create four identical TMR sensors that have synthetic antiferromagnetic free layers as the top layer. The synthetic antiferromagnetic free layers comprise a first magnetic layer, a spacer layer, and a second magnetic layer. After forming the four identical TMR sensors, the spacer layer and the second magnetic layer are removed from two TMR sensors. Following the removal of the spacer layer and the second magnetic layer, a new magnetic layer is formed on the now exposed first magnetic layer such that the new magnetic layer has substantially the same thickness as the spacer layer and second magnetic layer combined.Type: ApplicationFiled: December 30, 2019Publication date: February 25, 2021Inventors: Yuankai ZHENG, Christian KAISER, Zhitao DIAO, Chih-Ching HU, Chen-jung CHIEN, Yung-Hung WANG, Ming MAO, Ming JIANG
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Publication number: 20200286508Abstract: A read head includes a first ferromagnetic layer, a second ferromagnetic layer, a first diffusion-assist nonmagnetic metallic layer located between the first ferromagnetic layer and the second ferromagnetic layer, a second diffusion-assist nonmagnetic metallic layer located between the first ferromagnetic layer and the second ferromagnetic layer, and a semiconductor spacer layer located between the first diffusion-assist nonmagnetic metallic layer and the second diffusion-assist nonmagnetic metallic layer.Type: ApplicationFiled: March 5, 2019Publication date: September 10, 2020Inventors: Yuankai ZHENG, Christian KAISER, Zhitao DIAO
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Patent number: 10755733Abstract: A read head includes a first ferromagnetic layer, a second ferromagnetic layer, a first diffusion-assist nonmagnetic metallic layer located between the first ferromagnetic layer and the second ferromagnetic layer, a second diffusion-assist nonmagnetic metallic layer located between the first ferromagnetic layer and the second ferromagnetic layer, and a semiconductor spacer layer located between the first diffusion-assist nonmagnetic metallic layer and the second diffusion-assist nonmagnetic metallic layer.Type: GrantFiled: March 5, 2019Date of Patent: August 25, 2020Assignee: SANDISK TECHNOLOGIES LLCInventors: Yuankai Zheng, Christian Kaiser, Zhitao Diao
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Patent number: 10446209Abstract: A method and system for providing a magnetic element and a magnetic memory utilizing the magnetic element are described. The magnetic element is used in a magnetic device that includes a contact electrically coupled to the magnetic element. The method and system include providing pinned, nonmagnetic spacer, and free layers. The free layer has an out-of-plane demagnetization energy and a perpendicular magnetic anisotropy corresponding to a perpendicular anisotropy energy that is less than the out-of-plane demagnetization energy. The nonmagnetic spacer layer is between the pinned and free layers. The method and system also include providing a perpendicular capping layer adjoining the free layer and the contact. The perpendicular capping layer induces at least part of the perpendicular magnetic anisotropy in the free layer. The magnetic element is configured to allow the free layer to be switched between magnetic states when a write current is passed through the magnetic element.Type: GrantFiled: February 25, 2011Date of Patent: October 15, 2019Assignee: Samsung Semiconductor Inc.Inventors: Steven M. Watts, Zhitao Diao, Xueti Tang, Kiseok Moon, Mohamad Towfik Krounbi
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Patent number: 9858951Abstract: A method provides a read sensor stack including an antiferromagnetic (AFM) layer, a pinned layer on the AFM layer, a free layer, and a nonmagnetic layer between the free and pinned layers. Providing the AFM layer includes depositing an AFM layer first portion at a first elevated temperature and at a rate of at least 0.1 Angstrom/second. This AFM layer first portion is annealed in-situ at at least one hundred degrees Celsius. An AFM sublayer is deposited at an elevated temperature and at a sublayer deposition rate of less than 0.1 Angstrom/second. The already-deposited portion of the AFM layer is annealed in-situ at at least one hundred degrees Celsius and less than five hundred degrees Celsius. The sublayer depositing and annealing steps may be repeated in order at least once to provide an AFM layer second portion that has multiple sublayers and is thinner than the AFM layer first portion.Type: GrantFiled: December 1, 2015Date of Patent: January 2, 2018Assignee: WESTERN DIGITAL (FREMONT), LLCInventors: Yuankai Zheng, Qunwen Leng, Xin Jiang, Zhitao Diao, Christian Kaiser
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Patent number: 9830936Abstract: A tunnel magnetoresistance (TMR) read sensor having a tabbed AFM layer and an extended pinned layer and methods for making the same are provided. The TMR read sensor has an AFM layer recessed from the air bearing surface, providing a reduced shield-to-shield distance.Type: GrantFiled: November 17, 2015Date of Patent: November 28, 2017Assignee: WESTERN DIGITAL (FREMONT), LLCInventors: Shaoping Li, Yuankai Zheng, Gerardo A. Bertero, Qunwen Leng, Michael L. Mallary, Rongfu Xiao, Ming Mao, Zhihong Zhang, Anup G. Roy, Chen Jung Chien, Zhitao Diao, Ling Wang
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Patent number: 9508365Abstract: A magnetic read apparatus has an air-bearing surface (ABS) and includes a shield, a crystal decoupling structure on the shield and a read sensor on the crystal decoupling structure. The crystal decoupling structure includes at least one of a magnetic high crystalline temperature amorphous alloy layer and a combination of a high crystalline temperature amorphous layer and an amorphous magnetic layer. The high crystalline temperature amorphous layer has a crystalline temperature of at least three hundred degrees Celsius. The amorphous magnetic layer is amorphous as-deposited.Type: GrantFiled: June 24, 2015Date of Patent: November 29, 2016Assignee: WESTERN DIGITAL (FREMONT), LLC.Inventors: Yuankai Zheng, Qunwen Leng, Xin Jiang, Tong Zhao, Zhitao Diao, Christian Kaiser, Zhipeng Li, Jianxin Fang
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Patent number: 9412787Abstract: A magnetic element and a magnetic memory utilizing the magnetic element are described. A contact is electrically coupled to the magnetic element. The magnetic element includes pinned, nonmagnetic spacer, and free layers and a perpendicular capping layer adjoining the free layer and the contact. The free layer has an out-of-plane demagnetization energy and a perpendicular magnetic anisotropy corresponding to a perpendicular anisotropy energy that is less than the out-of-plane demagnetization energy. The nonmagnetic spacer layer is between the pinned and free layers. The perpendicular capping layer induces at least part of the perpendicular magnetic anisotropy. The free layer is switchable between magnetic states when a write current is passed through the magnetic element. The free layer includes ferromagnetic layers interleaved with capping layer(s) such that a ferromagnetic layer resides at an edge of the free layer.Type: GrantFiled: February 10, 2014Date of Patent: August 9, 2016Assignee: SAMSUNG ELECTRONICS CO., LTD.Inventors: Steven M. Watts, Zhitao Diao, Xueti Tang