Tunnel magnetoresistive sensor having conductive ceramic layers

Patent metadata

Field	Value
Publication number	US-9508367-B1
Application number	US-201615014983-A
Country	US
Kind code	B1
Filing date	Feb 3, 2016
Priority date	Feb 3, 2016
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

Abstract

In one general embodiment, an apparatus includes a sensor having an active tunnel magnetoresistive region, magnetic shields flanking the tunnel magnetoresistive region, and spacers between the active tunnel magnetoresistive region and the magnetic shields. The active tunnel magnetoresistive region includes a free layer, a tunnel barrier layer and a reference layer. At least one of the spacers includes an electrically conductive ceramic layer. The presence of the electrically conductive ceramic layer enables current-perpendicular-to-plane operation, while enhancing wear resistance and resistance to deformities of the thin films.

First claim

What is claimed is:

1. An apparatus, comprising:
a sensor having an active tunnel magnetoresistive region, magnetic shields flanking the tunnel magnetoresistive region, and spacers between the active tunnel magnetoresistive region and the magnetic shields,
wherein the active tunnel magnetoresistive region includes a free layer, a tunnel barrier layer and a reference layer,
wherein at least one of the spacers includes an electrically conductive ceramic layer.

2. An apparatus as recited in claim 1 , wherein a thickness of the ceramic layer is at least 2 nanometers.

3. An apparatus as recited in claim 1 , wherein a thickness of the ceramic layer is at least 10 nanometers.

4. An apparatus as recited in claim 1 , wherein the ceramic layer includes ruthenium oxide.

5. An apparatus as recited in claim 4 , wherein the ceramic layer is sandwiched between ruthenium films.

6. An apparatus as recited in claim 4 , wherein the ruthenium oxide in the ceramic layer is at least partially crystalline.

7. An apparatus as recited in claim 1 , wherein the ceramic layer is at least partially crystalline.

8. An apparatus as recited in claim 1 , wherein the ceramic layer includes at least one material selected from a group consisting of: alumina, titanium nitride, zirconia, ruthenium oxide, iridium oxide, silicon nitride, and silicon carbide.

9. An apparatus as recited in claim 1 , comprising an array of the sensors sharing a common media-facing surface.

10. An apparatus as recited in claim 9 , wherein no write transducers are present on the common media-facing surface.

11. An apparatus as recited in claim 1 , wherein the sensor is an electronic lapping guide.

12. An apparatus as recited in claim 1 , wherein both spacers include an electrically conductive ceramic layer.

13. An apparatus as recited in claim 12 , wherein the electrically conductive ceramic layer of one of the spacers has a different composition than the electrically conductive ceramic layer of the other of the spacers.

14. An apparatus as recited in claim 1 , wherein at least one of the spacers includes a metal.

15. An apparatus as recited in claim 1 , wherein one of the spacers includes the electrically conductive ceramic layer and another of the spacers is metallic or a metallic alloy.

16. An apparatus as recited in claim 1 , comprising a durable layer above an upper one of the shields and/or below a lower one of the shields, the durable layer being harder than the shield nearest thereto.

17. An apparatus as recited in claim 1 , comprising a second electrically conductive ceramic layer between the active tunnel magnetoresistive region and at least one of the spacers.

18. An apparatus as recited in claim 1 , comprising:
a drive mechanism for passing a magnetic medium over the sensor; and
a controller electrically coupled to the sensor.

19. An apparatus, comprising:
a sensor having an active tunnel magnetoresistive region, magnetic shields flanking the tunnel magnetoresistive region, spacers between the tunnel magnetoresistive region and the magnetic shields, and an electrically conductive ceramic layer between the active tunnel magnetoresistive region and at least one of the spacers,
wherein the active tunnel magnetoresistive region includes a free layer, a tunnel barrier layer and a reference layer.

20. An apparatus as recited in claim 19 , wherein a thickness of ceramic layer is at least 2 nanometers.

21. An apparatus as recited in claim 19 , wherein the ceramic layer includes ruthenium oxide.

22. An apparatus as recited in claim 21 , wherein the ceramic layer is sandwiched between ruthenium films.

23. An apparatus as recited in claim 21 , wherein the ruthenium oxide in the ceramic layer is at least partially crystalline.

24. An apparatus as recited in claim 19 , wherein the ceramic layer is at least partially crystalline.

25. An apparatus as recited in claim 19 , wherein ceramic layers are positioned between the active tunnel magnetoresistive region and both of the spacers.

Assignees

• IBM

Inventors

• Biskeborn Robert G
• Lo Calvin S
• Rice Philip M
• Topuria Teya

Classifications

• 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

• G11B5/3945

  Heads comprising more than one sensitive element · CPC title

• G11B5/3106

  where the integrated or assembled structure comprises means for conditioning against physical detrimental influence, e.g. wear, contamination (G11B5/3133 takes precedence) · CPC title

• G11B5/3948

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

• G11B5/3909

  Arrangements using a magnetic tunnel junction · CPC title