公开(公告)号：US11694713B2

公开(公告)日：2023-07-04

申请号：US17100199

申请日：2020-11-20

Applicant: Western Digital Technologies, Inc. ,  Tokyo Institute of Technology

Inventor： Quang Le ,  Cherngye Hwang ,  Brian R. York ,  Thao A. Nguyen ,  Zheng Gao ,  Kuok San Ho ,  Pham Nam Hai

IPC: G11B5/11 ,  H01F10/32 ,  G11B5/147 ,  H10N50/85 ,  H10N52/80 ,  H10B61/00 ,  H10N52/00 ,  G11B5/00

CPC classification number: G11B5/11 ,  G11B5/147 ,  H01F10/329 ,  H01F10/3254 ,  H01F10/3272 ,  H10B61/00 ,  H10N50/85 ,  H10N52/00 ,  H10N52/80 ,  G11B2005/0024

Abstract: A spin-orbit torque (SOT) magnetic tunnel junction (MTJ) device includes a substrate, a buffer layer formed over the substrate, and a bismuth antimony (BiSb) layer formed over the buffer layer, the BiSb layer having a (012) orientation. In certain embodiments, the SOT MTJ device is part of a microwave assisted magnetic recording (MAMR) write head. In certain embodiments, the SOT MTJ device is part of a magnetoresistive random access memory (MRAM) device.

公开(公告)号：US11489108B2

公开(公告)日：2022-11-01

申请号：US16861118

申请日：2020-04-28

Applicant: Western Digital Technologies, Inc.

Inventor： Quang Le ,  Cherngye Hwang ,  Brian R. York ,  Andrew Chen ,  Thao A. Nguyen ,  Yongchul Ahn ,  Xiaoyong Liu ,  Hongquan Jiang ,  Zheng Gao ,  Kuok San Ho

IPC: H01L29/82 ,  H01L43/04 ,  H01L27/22 ,  H01L43/06 ,  H01L43/10 ,  H01F10/32 ,  G11B5/39 ,  G11B5/00

Abstract: A spin-orbit torque (SOT) magnetic tunnel junction (MTJ) device includes a substrate, a seed layer over the substrate, and a bismuth antimony (BiSb) layer having (0120) orientation on the seed layer. The seed layer includes a silicide layer and a surface control layer. The silicide layer includes a material of NiSi, NiFeSi, NiFeTaSi, NiCuSi, CoSi, CoFeSi, CoFeTaSi, CoCuSi, or combinations thereof. The surface control layer includes a material of NiFe, NiFeTa, NiTa, NiW, NiFeW, NiCu, NiCuM, NiFeCu, CoTa, CoFeTa, NiCoTa, Co, CoM, CoNiM, CoNi, NiSi, CoSi, NiCoSi, Cu, CuAgM, CuM, or combinations thereof, in which M is Fe, Cu, Co, Ta, Ag, Ni, Mn, Cr, V, Ti, or Si.

公开(公告)号：US10950258B1

公开(公告)日：2021-03-16

申请号：US16883911

申请日：2020-05-26

Applicant: Western Digital Technologies, Inc.

Inventor： Zheng Gao ,  Susumu Okamura ,  James Mac Freitag

IPC: G11B5/235 ,  G11B5/127 ,  G11B5/31 ,  G11B5/02

Abstract: Aspects of the present disclosure relate to spin torque oscillator (STO) and methods, such as spin torque oscillators used in write heads of magnetic media drives. The STO includes a seed layer, a spin polarization layer (SPL), a spacer layer, a field generation layer (FGL), a capping layer. An insertion layer is disposed within the STO. The insertion layer increases the negative Hk. The insertion layer may be located between the FGL and the capping layer, as well as between the FGL and the spacer layer. For a reverse STO, the insertion layer may be disposed between the FGL and the seed layer, as well as between the FGL and the spacer layer.

公开(公告)号：US10566015B2

公开(公告)日：2020-02-18

申请号：US15976606

申请日：2018-05-10

Applicant: Western Digital Technologies, Inc.

Inventor： James Mac Freitag ,  Zheng Gao ,  Masahiko Hashimoto ,  Sangmun Oh ,  Hua Al Zeng

IPC: G11B5/127 ,  G11B5/39 ,  G11C11/16 ,  G11B5/17 ,  G11B5/60 ,  G11B5/31 ,  G11B5/35 ,  G11B5/00

Abstract: A spin transfer torque (STT) device has a free ferromagnetic layer that includes a Heusler alloy layer and a template layer beneath and in contact with the Heusler alloy layer. The template layer may be a ferromagnetic alloy comprising one or more of Co, Ni and Fe and the element X, where X is selected from one or, more of Ta, B, Hf, Zr, W, Nb and Mo. A CoFe nanolayer may be formed below and in contact with the template layer. The STT device may be a spin-torque oscillator (STO), like a STO incorporated into the write head of a magnetic recording disk drive. The STT device may also be a STT in-plane or perpendicular magnetic tunnel junction (MTJ) cell for magnetic random access memory (MRAM). The template layer reduces the critical current density of the STT device.

公开(公告)号：US10121500B2

公开(公告)日：2018-11-06

申请号：US16005835

申请日：2018-06-12

Applicant: Western Digital Technologies, Inc.

Inventor： Zheng Gao ,  James Mac Freitag

IPC: G11B5/39 ,  H01L43/08 ,  G11C11/16 ,  H01L43/10

Abstract: In one embodiment, a system includes a sensor, the sensor having a free layer, a ferromagnetic spin sink layer spaced from the free layer, the spin sink layer being operative to reduce a spin-induced damping in the free layer during operation of the sensor, and a nonmagnetic spacer layer positioned between the free layer and the spin sink layer, the spacer layer having a long spin-diffusion length.

公开(公告)号：US11657836B2

公开(公告)日：2023-05-23

申请号：US17649246

申请日：2022-01-28

Applicant: Western Digital Technologies, Inc.

Inventor： James Mac Freitag ,  Susumu Okamura ,  Alexander Goncharov ,  Zheng Gao

IPC: G11B5/127 ,  G11B5/02 ,  G11B5/31 ,  G11B5/23

CPC classification number: G11B5/1278 ,  G11B5/02 ,  G11B5/23 ,  G11B5/313 ,  G11B5/314 ,  G11B5/315 ,  G11B5/3133 ,  G11B5/3146

Abstract: Aspects of the present disclosure generally relate to a magnetic recording head of a spintronic device, such as a write head of a data storage device, for example a magnetic media drive. In one example, a magnetic recording head includes a main pole, a trailing shield, and a spin torque layer (STL) between the main pole and the trailing shield. The magnetic recording head includes a first layer structure on the main pole, and the first layer structure includes a negative polarization layer. The magnetic recording head also includes a second layer structure disposed on the negative polarization layer and between the negative polarization layer and the STL. The negative polarization layer is an FeCr layer. The second layer structure includes a Cr layer disposed on the FeCr layer, and a Cu layer disposed on the Cr layer and between the Cr layer and the STL.

公开(公告)号：US11257514B2

公开(公告)日：2022-02-22

申请号：US16912509

申请日：2020-06-25

Applicant: Western Digital Technologies, Inc.

Inventor： James Mac Freitag ,  Susumu Okamura ,  Alexander Goncharov ,  Zheng Gao

IPC: G11B5/127 ,  G11B5/02 ,  G11B5/31 ,  G11B5/23

Abstract: Aspects of the present disclosure generally relate to a magnetic recording head of a spintronic device, such as a write head of a data storage device, for example a magnetic media drive. In one example, a magnetic recording head includes a main pole, a trailing shield, and a spin torque layer (STL) between the main pole and the trailing shield. The magnetic recording head includes a first layer structure on the main pole, and the first layer structure includes a negative polarization layer. The magnetic recording head also includes a second layer structure disposed on the negative polarization layer and between the negative polarization layer and the STL. The negative polarization layer is an FeCr layer. The second layer structure includes a Cr layer disposed on the FeCr layer, and a Cu layer disposed on the Cr layer and between the Cr layer and the STL.

公开(公告)号：US11127420B1

公开(公告)日：2021-09-21

申请号：US16450857

申请日：2019-06-24

Applicant: Western Digital Technologies, Inc.

Inventor： James Mac Freitag ,  Zheng Gao ,  Susumu Okamura ,  Brian York

IPC: G11B5/147 ,  G11B5/31 ,  G11B11/105 ,  H01F10/30 ,  H01F10/32 ,  G11B5/00

Abstract: Certain embodiments are directed to a spin torque oscillator (STO) device in a microwave assisted magnetic recording (MAMR) device. The magnetic recording head includes a seed layer, a spin polarization layer over the seed layer, a spacer layer over the spin polarization layer, and a field generation layer is over the spacer layer. In one embodiment, the seed layer comprises a tantalum alloy layer. In another embodiment, the seed layer comprises a template layer and a damping reduction layer over the template layer. In yet another embodiment, the seed layer comprises a texture reset layer, a template layer on the texture reset layer, and a damping reduction layer on the template layer.

公开(公告)号：US10943611B1

公开(公告)日：2021-03-09

申请号：US16836687

申请日：2020-03-31

Applicant: Western Digital Technologies, Inc.

Inventor： James Mac Freitag ,  Zheng Gao ,  Susumu Okamura ,  Yongchul Ahn ,  Aron Pentek ,  Amanda Baer

IPC: G11B5/235 ,  G11B5/31 ,  G11B5/127 ,  G11B5/39 ,  G11B5/02 ,  G11B5/00 ,  G11B5/23

Abstract: In one embodiment, a write head includes a spin polarization layer (SPL) over a seed layer. A spacer layer is over the SPL. A trailing shield is over the spacer layer. The spacer layer forms a first interface between the spacer layer and the trailing shield and forms a second interface between the spacer layer and the SPL. The first interface has an area larger than an area of the second interface. In another embodiment, a write head includes a SPL over a spacer layer. A capping layer is over the SPL. A trailing shield is over the capping layer. The spacer layer forms a first interface between the spacer layer and the main pole and forms a second interface between the spacer layer and the SPL. The first interface has an area larger than an area of the second interface.

公开(公告)号：US20190279666A1

公开(公告)日：2019-09-12

申请号：US15596198

申请日：2017-05-16

Applicant: Western Digital Technologies, Inc.

Inventor： James Mac Freitag ,  Susumu Okamura ,  Masahiko Hashimoto ,  Zheng Gao

IPC: G11B5/39 ,  G11B5/60

Abstract: A spin transfer torque (STT) device is formed on an electrically conductive substrate and includes a ferromagnetic free layer near the substrate, a ferromagnetic polarizing layer and a nonmagnetic spacer layer between the free layer and the polarizing layer. A multilayer structure is located between the substrate and the free layer. The multilayer structure includes a metal or metal alloy seed layer for the free layer and an intermediate oxide layer below and in contact with the seed layer. The intermediate oxide layer reflects spin current from the free layer and thus reduces undesirable damping of the oscillation of the free layer's magnetization by the seed layer.