Patents by Inventor Cherng Chyi Han
Cherng Chyi Han 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: 11011192Abstract: An optically shielded (thermally assisted magnetic recording (TAMR) head comprises a perpendicular magnetic recording (PMR) write head and a near-field transducer (NFT) having an emerging peg at the air-bearing surface (ABS). Self-aligned optical side shields (SA-OSS) are formed using a self-aligning process that positions the shields symmetrically relative to the emergent peg of the NFT. As a result of the symmetric positioning the down-track and cross-track near-field and near-field gradients are significantly sharpened.Type: GrantFiled: February 25, 2020Date of Patent: May 18, 2021Assignee: Headway Technologies, Inc.Inventors: Weihao Xu, Ittetsu Kitajima, Cherng-Chyi Han, Xuhui Jin, Weisheng Hu, Ethan Lo
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Patent number: 10586560Abstract: A PMR (perpendicular magnetic recording) head is configured for thermally assisted magnetic recording (TAMR). The thermal energy is supplied by the near-fields of plasmons and the near-fields are directed to a magnetic recording medium by a PPG layer. The PPG layer is Rhodium (Rh) whose small-grained crystal structure normally makes it subject to thermal deformations and other weaknesses. By growing the PPG layer on a thin template layer (TTL), the portion of the PPG layer adjacent to the air-bearing surface (ABS) develops a larger grain size and stronger forces between its atomic constituents which makes it resistant to those deformations.Type: GrantFiled: March 5, 2019Date of Patent: March 10, 2020Assignee: Headway Technologies, Inc.Inventors: Shengyuan Wang, Weihao Xu, Cherng-Chyi Han, Xuhui Jin, Min Li, Kunliang Zhang
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Patent number: 10262683Abstract: A near field transducer (NFT) is formed between a waveguide and main pole layer at an air bearing surface (ABS). The NFT includes a resonator body layer made of Au, for example, with a front side at a first plane that is recessed a first distance from the ABS and a back side that is at a second plane formed parallel to the ABS and first plane. The NFT also has a peg layer with a rectangular peg portion between the ABS and first plane, and a larger back portion between the first and second planes that overlays directly above the resonator body layer. The peg layer is preferably made of Rh to improve mechanical stability of the NFT without significantly degrading overall optical efficiency of the NFT. A blocker may be formed between the ABS and waveguide to prevent light not coupled to the NFT from reaching the ABS.Type: GrantFiled: February 1, 2016Date of Patent: April 16, 2019Assignee: Headway Technologies, Inc.Inventors: Matteo Staffaroni, Xuhui Jin, Weihao Xu, Cherng-Chyi Han, Weisheng Hu, Shengyuan Wang
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Patent number: 10186288Abstract: A method of forming a TAMR (thermally assisted magnetic recording) write head that uses weakly plasmonic materials that are mechanically strong and thermally stable to create plasmon near field energy. The replacement of highly plasmonic materials like Au with a weakly plasmonic material like Rh avoids the thermal deformations of softer metals like Au. To maintain the performance of the head, it includes pre-focusing structures that concentrate plasmon energy as it moves towards the air bearing surface (ABS). A waveguide blocker at the distal end of the waveguide enhances the plasmons at the interface between the blocker and the dielectric material at the distal end of the waveguide. A pair of symmetrically disposed optical side shields (OSS) are formed to either side of the pole tip and a weakly plasmonic optical field enhancer of sharply defined line-width further strengthens the optical field at its point of application.Type: GrantFiled: April 30, 2018Date of Patent: January 22, 2019Assignee: Headway Technologies, Inc.Inventors: Weihao Xu, Cherng-Chyi Han, Weisheng Hu, Shengyuan Wang, Wen-Ding Huang, Ittetsu Kitajima
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Patent number: 10152991Abstract: A method for manufacturing a TAMR (thermal assisted magnetic recording) write head. The write head has a metal blocker formed against a distal end of a waveguide. The waveguide focuses optical radiation on an adjacent plasmon generator where it excites plasmon modes that heat the recording medium. Although the plasmon generator typically heats the recording medium using the plasmon near field to supply the required Joule heating, an unblocked waveguide would also send optical radiation to the medium and surrounding structures producing unwanted heating and device unreliability. The role of the blocker is to block the unwanted optical radiation and, thereby, to limit the heating to that supplied by the plasmon near field.Type: GrantFiled: December 11, 2017Date of Patent: December 11, 2018Assignee: Headway Technologies, Inc.Inventors: Tsutomu Chou, Kouji Shimazawa, Tobias Maletzky, Weihao Xu, Shinji Hara, Yoshihiro Tsuchiya, Yiming Wang, Cherng-Chyi Han, Xuhui Jin
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Publication number: 20180182419Abstract: A TAMR (thermal assisted magnetic recording) write head and a method of its fabrication. The write head has a metal blocker formed against a distal end of a waveguide. The waveguide focuses optical radiation on an adjacent plasmon generator where it excites plasmon modes that heat the recording medium. Although the plasmon generator typically heats the recording medium using the plasmon near field to supply the required Joule heating, an unblocked waveguide would also send optical radiation to the medium and surrounding structures producing unwanted heating and device unreliability. The role of the blocker is to block the unwanted optical radiation and, thereby, to limit the heating to that supplied by the plasmon near field.Type: ApplicationFiled: December 11, 2017Publication date: June 28, 2018Inventors: Tsutomu Chou, Kouji Shimazawa, Tobias Maletzky, Weihao Xu, Shinji Hara, Yoshihiro Tsuchiya, Yiming Wang, Cherng-Chyi Han, Xuhui Jin
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Patent number: 9852752Abstract: A TAMR (thermal assisted magnetic recording) write head has a metal blocker formed against a distal end of a waveguide. The waveguide focuses optical radiation on an adjacent plasmon generator where it excites plasmon modes that heat the recording medium. Although the plasmon generator typically heats the recording medium using the plasmon near field to supply the required Joule heating, an unblocked waveguide would also send optical radiation to the medium and surrounding structures producing unwanted heating and device unreliability. The role of the blocker is to block the unwanted optical radiation and, thereby, to limit the heating to that supplied by the plasmon near field.Type: GrantFiled: August 12, 2016Date of Patent: December 26, 2017Assignee: Headway Technologies, Inc.Inventors: Tsutomu Chou, Kouji Shimazawa, Tobias Maletzky, Weihao Xu, Shinji Hara, Yoshihiro Tsuchiya, Yiming Wang, Cherng-Chyi Han, Xuhui Jin
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Publication number: 20170221505Abstract: A near field transducer (NFT) is formed between a waveguide and main pole layer at an air bearing surface (ABS). The NFT includes a resonator body layer made of Au, for example, with a front side at a first plane that is recessed a first distance from the ABS and a back side that is at a second plane formed parallel to the ABS and first plane. The NFT also has a peg layer with a rectangular peg portion between the ABS and first plane, and a larger back portion between the first and second planes that overlays directly above the resonator body layer. The peg layer is preferably made of Rh to improve mechanical stability of the NFT without significantly degrading overall optical efficiency of the NFT. A blocker may be formed between the ABS and waveguide to prevent light not coupled to the NFT from reaching the ABS.Type: ApplicationFiled: February 1, 2016Publication date: August 3, 2017Inventors: Matteo Staffaroni, Xuhui Jin, Weihao Xu, Cherng-Chyi Han, Weisheng Hu, Shengyuan Wang
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Patent number: 9337414Abstract: A TMR (tunneling magnetoresistive) read sensor is formed in which a portion of the sensor stack containing the ferromagnetic free layer and the tunneling barrier layer is patterned to define a narrow trackwidth, but a synthetic antiferromagnetic pinning/pinned layer is left substantially unpatterned and extends in substantially as-deposited form beyond the lateral edges bounding the patterned portion. The narrow trackwidth of the patterned portion permits high resolution for densely recorded data. The larger pinning/pinned layer significantly improves magnetic stability and reduces thermal noise, while the method of formation eliminates possible ion beam etch (IBE) or reactive ion etch (RIE) damage to the edges of the pinning/pinned layer.Type: GrantFiled: March 14, 2013Date of Patent: May 10, 2016Assignee: Headway Technologies, Inc.Inventors: Min Li, Ruhang Ding, Cherng Chyi Han, Jianing Zhou, Minghui Yu
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Publication number: 20150029616Abstract: A perpendicular magnetic recording (PMR) head is fabricated with a main pole shielded laterally by a pair of side shields, shielded above by a trailing shield and shielded optionally below by a leading shield. The shields and the seed layers on which they are formed are formed of materials having substantially the same physical characteristics including the same material composition, the same hardness, the same response to processes such as ion beam etching (IBE), chemical mechanical polishing (CMP), mechanical lapping, such as the slider ABS lapping, the same coefficient of thermal expansion (CTE) as well as the same Bs. Optionally, the trailing shield may be formed on a high Bs seed layer to provide the write head with improved down-track performance.Type: ApplicationFiled: September 12, 2014Publication date: January 29, 2015Inventors: Zhigang Bai, Yan Wu, Moris Dovek, Cherng Chyi Han
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Patent number: 8865008Abstract: A two part ion beam etch sequence involving low energy (<300 eV) is disclosed for fabricating a free layer width (FLW) as small as 20-25 nm in a MTJ element. A first etch process has one or more low incident angles and accounts for removal of 70% to 100% of the MTJ stack that is not covered by an overlying photoresist layer. The second etch process employs one or more high incident angles and a sweeping motion that is repeated during a plurality of cycles. Sidewall slope may be adjusted by varying the incident angle during either of the etch processes. FLW is about 30 nm less than an initial critical dimension in the photoresist layer while maintaining a MR ratio over 60% and low RA (resistance×area) value of 1.0 ohm-?m2.Type: GrantFiled: October 25, 2012Date of Patent: October 21, 2014Assignee: Headway Technologies, Inc.Inventors: Ruhang Ding, Hui-Chuan Wang, Minghui Yu, Jianing Zhou, Min Li, Cherng Chyi Han
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Patent number: 8842389Abstract: A perpendicular magnetic recording (PMR) head is fabricated with a main pole shielded laterally by a pair of side shields, shielded above by a trailing shield and shielded optionally below by a leading shield. The shields and the seed layers on which they are formed are formed of materials having substantially the same physical characteristics including the same material composition, the same hardness, the same response to processes such as ion beam etching (IBE), chemical mechanical polishing (CMP), mechanical lapping, such as the slider ABS lapping, the same coefficient of thermal expansion (CTE) as well as the same Bs. Optionally, the trailing shield may be formed on a high Bs seed layer to provide the write head with improved down-track performance.Type: GrantFiled: October 26, 2009Date of Patent: September 23, 2014Assignee: Headway Technologies, Inc.Inventors: Zhigang Bai, Yan Wu, Moris Dovek, Cherng Chyi Han
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Publication number: 20140264665Abstract: A TMR (tunneling magnetoresistive) read sensor is formed in which a portion of the sensor stack containing the ferromagnetic free layer and the tunneling barrier layer is patterned to define a narrow trackwidth, but a synthetic antiferromagnetic pinning/pinned layer is left substantially unpatterned and extends in substantially as-deposited form beyond the lateral edges bounding the patterned portion. The narrow trackwidth of the patterned portion permits high resolution for densely recorded data. The larger pinning/pinned layer significantly improves magnetic stability and reduces thermal noise, while the method of formation eliminates possible ion beam etch (IBE) or reactive ion etch (RIE) damage to the edges of the pinning/pinned layer.Type: ApplicationFiled: March 14, 2013Publication date: September 18, 2014Applicant: HEADWAY TECHNOLOGIES, INC.Inventors: Min Li, Ruhang Ding, Cherng Chyi Han, Jianing Zhou, Minghui Yu
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Patent number: 8784674Abstract: A perpendicular magnetic recording (PMR) head is fabricated with a pole tip shielded laterally by a graded side shield that is conformal to the shape of the pole tip at an upper portion of the shield but not conformal to the pole tip at a lower portion. The shield includes a trailing shield, that is conformal to the trailing edge of the pole tip and may include a leading edge shield that magnetically connects two bottom ends of the graded side shield.Type: GrantFiled: December 6, 2013Date of Patent: July 22, 2014Assignee: Headway Technologies, Inc.Inventors: Yan Wu, Zhigang Bai, Moris Dovek, Cherng-Chyi Han, Min Li, Jianing Zhou, Jiun-Ting Lee, Min Zheng
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Patent number: 8728333Abstract: A three step ion beam etch (IBE) sequence involving low energy (<300 eV) is disclosed for trimming a sensor critical dimension (free layer width=FLW) to less than 50 nm. A first IBE step has a steep incident angle with respect to the sensor sidewall and accounts for 60% to 90% of the FLW reduction. The second IBE step has a shallow incident angle and a sweeping motion to remove residue from the first IBE step and further trim the sidewall. The third IBE step has a steep incident angle to remove damaged sidewall portions from the second step and accounts for 10% to 40% of the FLW reduction. As a result, FLW approaching 30 nm is realized while maintaining high MR ratio of over 60% and low RA of 1.2 ohm-?m2. Sidewall angle is manipulated by changing one or more ion beam incident angles.Type: GrantFiled: February 12, 2010Date of Patent: May 20, 2014Assignee: Headway Technologies, Inc.Inventors: Hui-Chuan Wang, Tong Zhao, Min Zheng, Minghui Yu, Min Li, Cherng Chyi Han
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Publication number: 20140116984Abstract: A two part ion beam etch sequence involving low energy (<300 eV) is disclosed for fabricating a free layer width (FLW) as small as 20-25 nm in a MTJ element. A first etch process has one or more low incident angles and accounts for removal of 70% to 100% of the MTJ stack that is not covered by an overlying photoresist layer. The second etch process employs one or more high incident angles and a sweeping motion that is repeated during a plurality of cycles. Sidewall slope may be adjusted by varying the incident angle during either of the etch processes. FLW is about 30 nm less than an initial critical dimension in the photoresist layer while maintaining a MR ratio over 60% and low RA (resistance×area) value of 1.0 ohm-?m2.Type: ApplicationFiled: October 25, 2012Publication date: May 1, 2014Applicant: HEADWAY TECHNOLOGIES, INC.Inventors: Ruhang Ding, Hui-Chuan Wang, Minghui Yu, Jianing Zhou, Min Li, Cherng Chyi Han
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Patent number: 8614860Abstract: A PMR head comprises a substrate, a magnetic pole formed over the substrate, the pole having a pole tip having a cross-sectional tapered shape wherein the pole tip is surrounded by a write gap layer, an integrated shield comprising side shields on the substrate laterally surrounding the pole tip and a trailing shield overlying the pole tip and integral with the side shields.Type: GrantFiled: November 7, 2011Date of Patent: December 24, 2013Assignee: Headway Technologies, Inc.Inventors: Cherng-Chyi Han, Lijie Guan, Joe Smyth, Moris Dovek
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Patent number: 8611046Abstract: A perpendicular magnetic recording (PMR) head is fabricated with a pole tip shielded laterally by a graded side shield that is conformal to the shape of the pole tip at an upper portion of the shield but not conformal to the pole tip at a lower portion. The shield includes a trailing shield, that is conformal to the trailing edge of the pole tip and may include a leading edge shield that magnetically connects two bottom ends of the graded side shield.Type: GrantFiled: April 19, 2010Date of Patent: December 17, 2013Assignee: Headway Technologies, Inc.Inventors: Yan Wu, Zhigang Bai, Moris Dovek, Cherng-Chyi Han, Min Li, Jianing Zhou, Jiun-Ting Lee, Min Zheng
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Patent number: 8472138Abstract: A magnetic pole suitable for perpendicular magnetic recording is described. This write pole is symmetrically located relative to its side shields and has at least three additional surfaces that are disposed to lie in planes that are normal to the substrate's top surface.Type: GrantFiled: July 1, 2011Date of Patent: June 25, 2013Assignee: Headway Technologies, Inc.Inventors: Cherng-Chyi Han, Min Li, Fenglin Liu, Chen-Jung Chien
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Patent number: 8379347Abstract: A PMR writer with a tapered main pole layer and tapered non-magnetic top-shaping layer is disclosed that minimizes trailing shield saturation. A second non-magnetic top shaping layer may be employed to reduce the effective TH size while the bulk of the trailing shield is thicker to allow a larger process window for back end processing. A sloped surface with one end at the ABS and a second end 0.05 to 0.3 microns from the ABS is formed at a 10 to 80 degree angle to the ABS and includes a sloped surface on the upper portion of the main pole layer and on the non-magnetic top shaping layer. An end is formed on the second non-magnetic top shaping layer at the second end of the sloped surface followed by forming a conformal write gap layer and then depositing the trailing shield on the write gap layer and along the ABS.Type: GrantFiled: July 20, 2012Date of Patent: February 19, 2013Assignee: Headway Technologies, Inc.Inventors: Lijie Guan, Joe Smyth, Moris Dovek, Yoshitaka Sasaki, Cherng-Chyi Han