-
公开(公告)号：US11011193B1
公开(公告)日：2021-05-18
申请号：US16781631
申请日：2020-02-04
Applicant: Headway Technologies, Inc.
Inventor： Yan Wu , Wenyu Chen , Shohei Kawasaki
Abstract: A spin transfer torque reversal assisted magnetic recording (STRAMR) structure is disclosed wherein two flux change layers (FCL1 and FCL2) are formed within a write gap (WG) and between a main pole (MP) trailing side and trailing shield (TS). Each FCL has a magnetization that flips to a direction substantially opposing a WG field when a direct current of sufficient current density is applied across the STRAMR device thereby increasing reluctance in the WG and producing a larger write field output at the air bearing surface. A reference layer (RL1) is used to reflect spin polarized electrons that exert spin torque on FCL1 and cause FCL1 magnetization to flip. A second reference layer (or the MP or TS) is employed to reflect spin polarize electrons that generate spin torque on FCL2 and flip FCL2 magnetization. Non-spin polarization preserving layers and spin polarization preserving layers are also in the STRAMR structure.
-
公开(公告)号：US10424326B1
公开(公告)日：2019-09-24
申请号：US16197586
申请日：2018-11-21
Applicant: Headway Technologies, Inc.
Inventor： Wenyu Chen , Shohei Kawasaki , Tetsuya Roppongi , Yan Wu
Abstract: A spin torque transfer (STT) assisted magnetic recording structure is disclosed wherein a magnetic flux guiding (MFG) device is formed between a main pole (MP) trailing side and a trailing shield (TS). The MFG device has a field generation layer (FGL) separated from first and second spin polarization (SP) layers by first and second non-magnetic layers, respectively. First and second SP layers have magnetizations in opposite directions so that when a direct current of sufficient magnitude is applied from the MP to TS, or from the TS to MP in other embodiments, FGL magnetization flips to a direction toward the MP and opposes a write gap field flux thereby enhancing the write field. Additive torque from two SP layers on the FGL enables lower current density for FGL flipping or a greater degree of FGL flipping at a given current density compared with MFG schemes having a single SP layer.
-
公开(公告)号：US12211526B2
公开(公告)日：2025-01-28
申请号：US18497867
申请日：2023-10-30
Applicant: Headway Technologies, Inc.
Inventor： Glen Garfunkel , Yan Wu , Wenyu Chen , Kunliang Zhang , Min Li , Shohei Kawasaki
Abstract: A read head includes a permanent magnet (PM) layer formed up to 100 nm behind a free layer where PM layer magnetization may be initialized in a direction that adjusts free layer (FL) bias point, and shifts sensor asymmetry (Asym) closer to 0% for individual heads at slider or Head Gimbal Assembly level to provide a significant improvement in device yield. Asym is adjusted using different initialization schemes and initialization directions. With individual heads, initialization direction is selected based on a prior measurement of asymmetry. The PM layer is CoPt or CoCrPt and has coercivity from 500 Oersted to 1000 Oersted. The PM layer may have a width equal to the FL, or in another embodiment, the PM layer adjoins a backside of the top shield and has a width equal to or greater than that of the FL.
-
公开(公告)号：US20240071414A1
公开(公告)日：2024-02-29
申请号：US18497867
申请日：2023-10-30
Applicant: HeadWay Technologies, INC.
Inventor： Glen Garfunkel , Yan Wu , Wenyu Chen , Kunliang Zhang , Min Li , Shohei Kawasaki
IPC: G11B5/39
CPC classification number: G11B5/3932 , G11B5/3909 , G11B5/3912 , G11B2005/0018
Abstract: A read head includes a permanent magnet (PM) layer formed up to 100 nm behind a free layer where PM layer magnetization may be initialized in a direction that adjusts free layer (FL) bias point, and shifts sensor asymmetry (Asym) closer to 0% for individual heads at slider or Head Gimbal Assembly level to provide a significant improvement in device yield. Asym is adjusted using different initialization schemes and initialization directions. With individual heads, initialization direction is selected based on a prior measurement of asymmetry. The PM layer is CoPt or CoCrPt and has coercivity from 500 Oersted to 1000 Oersted. The PM layer may have a width equal to the FL, or in another embodiment, the PM layer adjoins a backside of the top shield and has a width equal to or greater than that of the FL.
-
公开(公告)号：US20240029759A1
公开(公告)日：2024-01-25
申请号：US17872831
申请日：2022-07-25
Applicant: Headway Technologies, Inc.
Inventor： Wenyu Chen , Zhenyao Tang , Shohei Kawasaki , Tetsuya Roppongi
CPC classification number: G11B5/11 , G11B5/187 , G11B2005/0024
Abstract: The present embodiments relate to write heads implementing microwave-assisted magnetic recording utilizing multiple spin torque oscillators (STOs). Each STO can include a field-generation layer (FGL) that can oscillate in a same frequency and out of phase with one another. The layers in each STO can enable mutual spin transfer torques between adjacent layers, which can drive the FGLs into a large angle oscillation. The oscillation between the FGLs can cause a magnetic field to be generated that can assist in writing to a magnetic recording medium.
-
Patent Agency Ranking
公开(公告)号：US11568891B1
公开(公告)日：2023-01-31
申请号：US17538391
申请日：2021-11-30
Applicant: Headway Technologies, Inc.
Inventor： Wenyu Chen , Shohei Kawasaki , Tetsuya Roppongi
Abstract: A STRAMR structure is disclosed. The STRAMR structure can include a spin torque oscillator (STO) device in a WG provided between the mail pole (MP) trailing side and a trailing shield. The STO device, includes: a flux guiding layer that has a negative spin polarization (nFGL) with a magnetization pointing substantially parallel to the WG field without the current bias and formed between a first spin polarization preserving layer (ppL1) and a second spin polarization preserving layer (ppL2); a positive spin polarization (pSP) layer that adjoins the TS bottom surface; a non-spin polarization preserving layer (pxL) contacting the MP trailing side; a first negative spin injection layer (nSIL1) between the ppL2 and a third spin polarization preserving layer (ppL3); and a second negative spin injection layer (nSIL2) between the ppL3 and the pxL, wherein the nFGL, nSIL1, and nSIL2 have a spin polarization that is negative.
-
公开(公告)号：US20220199113A1
公开(公告)日：2022-06-23
申请号：US17691869
申请日：2022-03-10
Applicant: Headway Technologies, Inc.
Inventor： Ying Liu , Shohei Kawasaki , Wenyu Chen , Yuhui Tang
Abstract: A method of forming a spin transfer torque reversal assisted magnetic recording (STRAMR) writer is disclosed wherein a spin torque oscillator (STO) has a flux guiding layer (FGL) wherein magnetization flips to a direction substantially opposing the write gap (WG) field when sufficient current (IB) density is applied across the STO between a trailing shield and main pole (MP) thereby enhancing the MP write field. The FGL has a center portion with a larger magnetization saturation×thickness (MsT) than in FGL outer portions proximate to STO sidewalls. Accordingly, lower IB density is necessary to provide a given amount of FGL magnetization flipping and there is reduced write bubble fringing compared with writers having a FGL with uniform MsT. Lower MsT is achieved by partially oxidizing FGL outer portions. In some embodiments, there is a gradient in outer FGL portions where MsT increases with increasing distance from FGL sidewalls.
-
公开(公告)号：US11295768B1
公开(公告)日：2022-04-05
申请号：US17029698
申请日：2020-09-23
Applicant: Headway Technologies, Inc.
Inventor： Ying Liu , Shohei Kawasaki , Wenyu Chen , Yuhui Tang
Abstract: A spin transfer torque reversal assisted magnetic recording (STRAMR) writer is disclosed wherein a spin torque oscillator has a flux guiding layer (FGL) wherein magnetization flips to a direction substantially opposing the write gap (WG) field when sufficient current (IB) density is applied across the STO between a trailing shield and main pole (MP) thereby enhancing the MP write field. A key feature is that the FGL has a center portion with a larger magnetization saturation×thickness (MsT) than in FGL outer portions proximate to STO sidewalls. Accordingly, lower IB density is necessary to provide a given amount of FGL magnetization flipping and there is reduced write bubble fringing compared with writers having a FGL with uniform MsT. Lower MsT is achieved by partially oxidizing FGL outer portions. In some embodiments, there is a gradient in outer FGL portions where MsT increases with increasing distance from FGL sidewalls.
-
公开(公告)号：US20220093123A1
公开(公告)日：2022-03-24
申请号：US17029698
申请日：2020-09-23
Applicant: Headway Technologies, Inc.
Inventor： Ying Liu , Shohei Kawasaki , Wenyu Chen , Yuhui Tang
IPC: G11B5/39
Abstract: A spin transfer torque reversal assisted magnetic recording (STRAMR) writer is disclosed wherein a spin torque oscillator has a flux guiding layer (FGL) wherein magnetization flips to a direction substantially opposing the write gap (WG) field when sufficient current (IB) density is applied across the STO between a trailing shield and main pole (MP) thereby enhancing the MP write field. A key feature is that the FGL has a center portion with a larger magnetization saturation×thickness (MsT) than in FGL outer portions proximate to STO sidewalls. Accordingly, lower IB density is necessary to provide a given amount of FGL magnetization flipping and there is reduced write bubble fringing compared with writers having a FGL with uniform MsT. Lower MsT is achieved by partially oxidizing FGL outer portions. In some embodiments, there is a gradient in outer FGL portions where MsT increases with increasing distance from FGL sidewalls.
-
公开(公告)号：US10937450B1
公开(公告)日：2021-03-02
申请号：US16927205
申请日：2020-07-13
Applicant: Headway Technologies, Inc.
Inventor： Shohei Kawasaki , Wenyu Chen , Tetsuya Roppongi
Abstract: A spin transfer torque reversal assisted magnetic recording (STRAMR) device is disclosed wherein a flux guiding layer (FGL) magnetization flips to an opposite direction opposing the write gap (WG) field because of spin torque from an adjacent spin polarization (SP) layer and spin injection layer (SIL) when a current (Ia) of sufficient density is applied across the device and between the main pole (MP) and trailing shield (TS) thereby enhancing the MP write field. The SP layer adjoins the MP or TS and maintains a magnetization in the WG field direction. One or both of the SIL and FGL has a spin polarization from −0.4 to 0.3 and may be doped with C, N, or B so that the extent of FGL flipping is greater at a given current density than in the prior art where all magnetic layers within the STRAMR device have a positive spin polarization ≥0.4.
-
-
-
-
-
-
-
-
-
Search Results
20
records
(took 0.032 seconds)
