CoFe/Ni multilayer film with perpendicular anisotropy for microwave assisted magnetic recording

Patent metadata

Field	Value
Publication number	US-9558765-B2
Application number	US-201615162059-A
Country	US
Kind code	B2
Filing date	May 23, 2016
Priority date	May 11, 2010
Publication date	Jan 31, 2017
Grant date	Jan 31, 2017

Abstract

A spin transfer oscillator (STO) with a seed/FGL/spacer/SIL/capping configuration is disclosed with a composite seed layer made of Ta and a metal layer having a fcc(111) or hcp(001) texture to enhance perpendicular magnetic anisotropy (PMA) in an overlying (A1/A2) Y FeCo laminated field generation layer (FGL). The spin injection layer (SIL) may be laminated with a (A1/A2) X FeCo configuration. The FeCo layer in the SIL is exchanged coupled with the (A1/A2) X laminate (x is 5 to 50) to improve robustness. The (A1/A2) Y laminate (y=5 to 30) in the FGL may be exchange coupled with a high Bs layer to enable easier oscillations. A1 may be one of Co, CoFe, or CoFeR where R is a metal, and A2 is one of Ni, NiCo, or NiFe. The STO is typically formed between a main pole and trailing shield in a write head.

First claim

We claim:

1. A spin transfer oscillator (STO) structure in a spintronic device, comprising:
(a) a composite seed layer comprising at least a lower Ta layer formed on a substrate and a metal (M1) layer having a fcc(111) or hcp(001) crystal structure contacting the lower Ta layer;
(b) a field generation layer (FGL) that has an (A1/A2) Y /FeCo alloy configuration where A1 is one of Co, CoFe, or CoFeR wherein R is one of Ru, Rh, Pd, Ti, Zr, Hf, Ni, Cr, Mg, Mn, or Cu, and A2 is one of Ni, NiCo, and NiFe, and Y is a number of laminations, the (A1/A2) Y laminate has perpendicular magnetic anisotropy (PMA) and contacts a top surface of the composite seed layer and is one of (Co/NiFe) Y , (Co/NiCo) Y , (CoFe/NiFe) Y , (CoFe/NiCo) Y , (CoFeR/Ni) Y , (CoFeR/NiFe) Y , or (CoFeR/NiCo) Y where R is one of Ru, Rh, Pd, Ti, Zr, Hf, Ni, Cr, Mg, Mn, or Cu, and the FeCo alloy includes one or more of Al, Ge, Si, Ga, C, Se, and Sn and contacts a bottom surface of a non-magnetic spacer;
(c) the non-magnetic spacer;
(d) a laminated spin injection layer (SIL) with high perpendicular magnetic anisotropy (PMA) and with a (A1/A2) X /FeCo configuration contacting a top surface of the non-magnetic spacer wherein X is in a range from 5 to 50, and a thickness (t2) of each A2 magnetic layer is greater than a thickness (t1) of each A1 magnetic layer; and
(e) a capping layer contacting the FeCo layer of the SIL.

2. The STO structure of claim 1 wherein the Fe content in the FeCo alloy in the FGL is less than 50 atomic %.

3. The STO structure of claim 1 where Y is from about 5 to 30.

4. The STO structure of claim 1 wherein the non-magnetic spacer is comprised of Cu to give a CPP-GMR configuration or is made of AlOx, MgO, TiOx, TiAlOx, MgZnOx, or ZnOx to give a CPP-TMR configuration.

5. The STO structure of claim 1 wherein the M1 layer is Ru, Cu, or NiCr.

6. The STO structure of claim 1 wherein the composite seed layer has a Ta/Ru/Cu configuration.

7. The STO structure of claim 5 wherein the composite seed layer is further comprised of a metal (M2) layer where M2 is Ti, Pd, W, Rh, Au, or Ag to give a Ta/M1/M2 composite seed layer configuration.

Assignees

• Headway Tech Inc

Inventors

• Zhang Kunliang
• Li Min
• Zhou Yuchen

Classifications

• G11C11/161

  details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell · CPC title

• G11B2005/3996

  large or giant magnetoresistive effects [GMR], e.g. as generated in spin-valve [SV] devices · CPC title

• G11B5/3967

  Composite structural arrangements of transducers, e.g. inductive write and magnetoresistive read (G11B5/3906 takes precedence) · CPC title

• Y10T428/1121

  Multilayer · CPC title

• G11B2005/0024

  Microwave assisted recording · CPC title