IP Library › Granted Patent US 12,688,869
Granted Patent B2
US 12,688,869 · App. 18/893,605 · Granted Jul 21, 2026

Topological insulator based spin torque oscillator reader

Inventors: Xiaoyong Liu (San Jose, CA); Zhanjie Li (Pleasanton, CA); Quang Le (San Jose, CA); Brian R. York (San Jose, CA); Cherngye Hwang (San Jose, CA); Kuok San Ho (Emerald Hills, CA); Hisashi Takano (Fujisawa, JP)
Assignee: Western Digital Technologies, Inc.
G11B5/3909G11B5/3912G11B5/3932G11B5/3967G11B2005/3996
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Quick Facts
Patent No.
US 12,688,869
App. No.
18/893,605
Granted
Jul 21, 2026
Kind
B2
Abstract

The present disclosure generally relates to a bismuth antimony (BiSb) based STO (spin torque oscillator) sensor. The STO sensor comprises a SOT device and a magnetic tunnel junction (MTJ) structure. By utilizing a BiSb layer within the SOT device, a larger spin Hall angle (SHA) can be achieved, thereby improving the efficiency and reliability of the STO sensor.

Claims (48)

1 . A magnetic recording device, comprising:

a magnetic recording head, comprising:

a sensor, comprising:

an antiferromagnetic (AFM) layer disposed at a media facing surface (MFS);

a magnetic tunnel junction (MTJ) structure comprising a free layer; and

a spin orbit torque (SOT) device comprising a bismuth antimony (BiSb) layer;

means for flowing a current through the SOT device while reading data from a magnetic recording media; and

means for measuring frequency of a precession of the free layer, wherein the precession is responsive to a magnetic field generated by the magnetic recording media.

2 . The magnetic recording device of claim 1 , wherein the MTJ structure is disposed over the AFM layer, and wherein the SOT device is disposed over the MTJ structure.

3 . The magnetic recording device of claim 1 , wherein the MTJ structure is disposed over the SOT device, and wherein the AFM layer is disposed over the MTJ structure.

4 . The magnetic recording device of claim 1 , wherein the MTJ structure further comprises a first pinning layer, a Ru layer, and a second pinning layer.

5 . The magnetic recording device of claim 1 , wherein the sensor further comprises a first shield and a second shield, and wherein the AFM layer is disposed adjacent to the second shield.

6 . The magnetic recording device of claim 1 , wherein the sensor further comprises a first shield and a second shield, and wherein the AFM layer is disposed in contact with the first shield.

7 . A magnetic recording device, comprising:

a magnetic recording head, comprising:

a sensor, comprising:

an antiferromagnetic (AFM) layer disposed at a media facing surface (MFS);

a magnetic tunnel junction (MTJ) structure comprising:

a free layer;

a first pinning layer;

a Ru layer; and

a second pinning layer; and

a spin orbit torque (SOT) device comprising:

a first buffer layer;

a bismuth antimony (BiSb) layer disposed on the first buffer layer; and

a second buffer layer disposed on the BiSb layer;

means for flowing a current through the SOT device while reading data from a magnetic recording media; and

means for measuring frequency of a precession of the free layer, wherein the precession is responsive to a magnetic field generated by the magnetic recording media.

8 . The magnetic recording head of claim 7 , further comprising a seed layer disposed between the AFM layer and the MTJ structure.

9 . The magnetic recording device of claim 7 , wherein the MTJ structure is disposed over the AFM layer, and wherein the SOT device is disposed over the MTJ structure.

10 . The magnetic recording device of claim 9 , wherein the sensor further comprises a first shield and a second shield, wherein the AFM layer is disposed on the first shield.

11 . The magnetic recording device of claim 7 , wherein the MTJ structure is disposed over the SOT device, and wherein the AFM layer is disposed over the MTJ structure.

12 . The magnetic recording device of claim 11 , wherein the sensor further comprises a first shield, a capping layer disposed on the AFM layer, and a second shield disposed on the capping layer.

13 . A magnetic recording device, comprising:

a magnetic recording head, comprising:

a sensor, comprising:

an antiferromagnetic (AFM) layer;

a magnetic tunnel junction (MTJ) structure comprising a free layer; and

a spin orbit torque (SOT) device comprising a bismuth antimony (BiSb) layer, the SOT device being disposed in contact with the MTJ structure;

means for flowing a current through the SOT device while reading data from a magnetic recording media; and

means for measuring frequency of a precession of the free layer, wherein the precession is responsive to a magnetic field generated by the magnetic recording media.

14 . The magnetic recording device of claim 13 , wherein the MTJ structure is disposed over the AFM layer.

15 . The magnetic recording device of claim 13 , wherein the SOT device is disposed over the MTJ structure.

16 . The magnetic recording device of claim 13 , wherein the MTJ structure is disposed over the AFM layer, and wherein the SOT device is disposed over the MTJ structure.

17 . The magnetic recording device of claim 13 , wherein the sensor further comprises a first shield and a second shield, and wherein the AFM layer is disposed in contact with the first shield.

18 . The magnetic recording device of claim 13 , wherein the MTJ structure further comprises a first pinning layer, a Ru layer, and a second pinning layer.

19 . The magnetic recording device of claim 13 , wherein the SOT device further comprises one or more buffer layers.

20 . The magnetic recording head of claim 13 , further comprising a seed layer disposed between the AFM layer and the MTJ structure.