Two-dimensional magnetic recording device with center shield stabilized by recessed AFM layer

Patent metadata

Field	Value
Publication number	US-9570100-B1
Application number	US-201514918829-A
Country	US
Kind code	B1
Filing date	Oct 21, 2015
Priority date	Oct 21, 2015
Publication date	Feb 14, 2017
Grant date	Feb 14, 2017

Abstract

A two-dimensional magnetic recording (TDMR) read head with an antiferromagnetic (AFM) layer recessed behind a center shield. The TDMR read head comprises a first read sensor and a center shield over the first read sensor, wherein the center shield has a first thickness at an air-bearing surface (ABS) and a second thickness at a back surface, the first thickness being greater than the second thickness. A ferromagnetic layer is disposed over a portion of the center shield, wherein the ferromagnetic layer is recessed from the ABS. The TDMR read head also includes an antiferromagnetic layer over the ferromagnetic layer and a second read sensor over the antiferromagnetic layer. By recessing the AFM layer away from the ABS, the down-track spacing between read sensors is reduced, thereby improving TDMR read head performance.

First claim

We claim:

1. A two-dimensional magnetic recording (TDMR) read head, comprising:
a first read sensor;
a center shield over the first read sensor, wherein the center shield has a first thickness at an air-bearing surface (ABS) and a second thickness at a back surface, the first thickness being greater than the second thickness;
a ferromagnetic layer over a portion of the center shield, wherein the ferromagnetic layer is recessed from the ABS;
an antiferromagnetic layer over the ferromagnetic layer, wherein the ferromagnetic layer is at least partially sandwiched between the antiferromagnetic layer and the center shield; and
a second read sensor over the antiferromagnetic layer.

2. The TDMR read head recited in claim 1 , wherein the second thickness is zero.

3. The TDMR read head recited in claim 1 , wherein the ferromagnetic layer comprises a stitch layer and a nanolayer.

4. The TDMR read head recited in claim 3 , wherein the nanolayer comprises cobalt-iron (CoFe) or cobalt.

5. The TDMR read head recited in claim 1 , further comprising an insulator layer disposed over the antiferromagnetic layer and an exposed portion of the center shield.

6. A hard disk drive comprising the TDMR read head recited in claim 1 .

7. A method of fabricating the TDMR read head recited in claim 1 , the method comprising:
forming the first read sensor;
forming the center shield over the first read sensor;
removing a part of the center shield so that the center shield has the first thickness at the ABS and the second thickness at the back surface;
forming the ferromagnetic layer over the portion of the center shield;
forming the antiferromagnetic layer over the ferromagnetic layer; and
forming the second read sensor over the antiferromagnetic layer.

8. The method of claim 7 , further comprising:
forming an insulator layer over the antiferromagnetic layer and an exposed portion of the center shield.

9. The method of claim 7 , wherein forming the ferromagnetic layer over the portion of the center shield comprises:
forming a stitch layer over the portion of the center shield; and
forming a nanolayer over the stitch layer.

10. The method of claim 9 , wherein the nanolayer comprises cobalt iron (CoFe) or cobalt.

11. The method of claim 7 , wherein removing the part of the center shield comprises:
applying a photoresist material; and
ion milling to remove the part of the center shield.

12. The method of claim 7 , wherein the second thickness is zero.

13. The TDMR read head fabricated using the method recited in claim 7 .

14. A hard disk drive comprising the TDMR read head recited in claim 13 .

15. A method of fabricating the TDMR read head recited in claim 1 , the method comprising:
forming the first read sensor;
forming the center shield over the first read sensor, the center shield made of a first material;
forming the ferromagnetic layer over the center shield;
forming the antiferromagnetic layer over the ferromagnetic layer;
removing a portion of the antiferromagnetic layer proximate the ABS;
removing a portion of the ferromagnetic layer proximate the ABS to expose a part of the center shield;
depositing additional first material over the exposed part of the center shield so that the center shield has the first thickness at the ABS and the second thickness at the back surface; and
forming the second read sensor over the antiferromagnetic layer.

16. The method of claim 15 , further comprising:
after depositing the additional first material over the exposed part of the center shield, forming an insulator layer over the antiferromagnetic layer and the center shield.

17. The method of claim 15 , wherein forming the ferromagnetic layer over the center shield comprises:
forming a stitch layer over the center shield; and
forming a nanolayer over the stitch layer.

18. The method of claim 17 , wherein the nanolayer comprises cobalt iron (CoFe) or cobalt.

19. The method of claim 15 , wherein removing the portion of the antiferromagnetic layer proximate the ABS comprises:
applying a photoresist material over the antiferromagnetic layer proximate the back surface; and
ion milling to remove the portion of the antiferromagnetic layer proximate the ABS.

20. The TDMR read head fabricated using the method recited in claim 15 .

21. A hard disk drive comprising the TDMR read head recited in claim 20 .

Assignees

• HGST Netherlands BV
• Western Digital Tech Inc

Inventors

• Freitag James
• Gao Zheng
• Maat Stefan

Classifications

• G11B5/3948

  the sensitive elements being active read-out elements · CPC title

• G11B5/3912 Primary

  Arrangements in which the active read-out elements are transducing in association with active magnetic shields, e.g. magnetically coupled shields (G11B5/3916 takes precedence) · CPC title

• G11B5/332

  using thin films (G11B5/372, G11B5/3903 take precedence) · CPC title

• G11B5/112

  Manufacture of shielding device · CPC title

• G11B5/4886

  relative to rotating disc · CPC title