US 12,068,008 B2
Magnetic flux guiding device with spin torque oscillator (STO) film having negative spin polarization layers in assisted writing application
Wenyu Chen, San Jose, CA (US); Shohei Kawasaki, Sunnyvale, CA (US); and Tetsuya Roppongi, San Jose, CA (US)
Assigned to Headway Technologies, Inc., Milpitas, CA (US)
Filed by Headway Technologies, Inc., Milpitas, CA (US)
Filed on Jan. 30, 2023, as Appl. No. 18/102,975.
Application 18/102,975 is a continuation of application No. 17/538,391, filed on Nov. 30, 2021, granted, now 11,568,891.
Prior Publication US 2023/0178103 A1, Jun. 8, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. G11B 5/235 (2006.01); G11B 5/11 (2006.01); G11B 5/127 (2006.01); G11B 5/31 (2006.01); G11B 5/00 (2006.01); G11B 5/39 (2006.01)
CPC G11B 5/3146 (2013.01) [G11B 5/11 (2013.01); G11B 5/1278 (2013.01); G11B 5/235 (2013.01); G11B 5/3133 (2013.01); G11B 5/314 (2013.01); G11B 5/3163 (2013.01); G11B 2005/0024 (2013.01); G11B 5/3912 (2013.01); G11B 5/3919 (2013.01); G11B 2005/3996 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A method of manufacturing a transfer torque reversal assisted magnetic recording (STRAMR) structure, the method comprising:
providing a main pole (MP) that is configured to generate a write field which is directed through a pole tip at an air bearing surface (ABS), and to generate a write gap (WG) field in a down-track direction across a spin torque oscillator (STO) device in a WG, and between a MP trailing side and a trailing shield (TS);
disposing the trailing shield (TS) with a side at the ABS, and a bottom surface facing the MP; and
providing the STO device, comprising:
(1) a flux guiding layer that has a negative spin polarization (nFGL), wherein the nFGL comprises a magnetization pointing substantially parallel to the WG field without a current bias and formed between a first spin polarization preserving layer (ppL1) and a second spin polarization preserving layer (ppL2);
(2) a positive spin polarization (pSP) layer that adjoins the TS bottom surface;
(3) a non-spin polarization preserving layer (pxL) contacting the MP trailing side;
(4) a first negative spin injection layer (nSIL1) between the ppL2 and a third spin polarization preserving layer (ppL3); and
(5) 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; and
applying a direct current (DC) of sufficient current density (J) from the TS to MP across the STO device, wherein the magnetization of the nFGL is configured to flip to a direction substantially antiparallel to the WG field, wherein the nSIL1 and nSIL2 are configured to exert an additive spin torque on the nFGL to cause a magnetization of the nFGL to flip to a direction substantially antiparallel to the WG field thereby increasing reluctance in the WG and enhancing the write field, and wherein the nSIL1 and nSIL2 have a saturation magnetization×thickness (Mst) product substantially less than that of the nFGL.