US 2004/0169962 A1 · Ferromagnetic/antiferromagnetic bilayer, including decoupler, for longitudinal bias

Abstract

As the dimensions of spin valve heads continue to be reduced, a number of difficulties are being encountered. One such is with the longitudinal bias when an external magnetic field can cause reversal of the hard magnet, thereby causing a hysteric response by the head. This coercivity reduction becomes more severe as the hard magnet becomes thinner. This problem has been overcome by inserting a decoupling layer between the antiferromagnetic layer that is used to stabilize the pinned layer of the spin valve itself and the soft ferromagnetic layer that is used for longitudinal biasing. This soft ferromagnetic layer is pinned by a second antiferromagnetic layer deposited on it on its far side away from the first antiferromagnetic layer. The presence of the decoupling layer ensures that the magnetization of the soft layer is determined only by the second antiferromagnetic layer. The inclusion of said decoupling layer allows more latitude in etch depth control during manufacturing.

Claims21

Dependent claims

A spin valve recording head, comprising:

a first dielectric layer on a magnetic shield;
on said first dielectric layer, a GMR enhancing seed layer;
on said seed layer, a first antiferromagnetic layer;
on said first antiferromagnetic layer, a bottom spin valve pedestal that further comprises a capping layer on a free layer on a non-magnetic spacer layer on a pinned layer, said pedestal having sidewalls that slope outwards away from the capping layer;
a part of the pinned layer, away from the capping layer, having been removed;
on the sidewalls, a decoupling layer that is between about 30 and 50 Angstroms thick;
on the decoupling layer only, a first layer of soft ferromagnetic material;
on said first layer of soft ferromagnetic material only, a second antiferromagnetic layer;
on the second antiferromagnetic layer, a conductive lead layer that overlaps the first soft ferromagnetic and second antiferromagnetic layers and contacts the capping layer;
and
on the capping layer and conductive layer, a second dielectric layer.

8 more elements

A process for manufacturing a spin valve recording head, comprising:

providing a first dielectric layer on a magnetic shield;
on said first dielectric layer, depositing a GMR enhancing seed layer;
on said seed layer, depositing a first antiferromagnetic layer;
in succession, depositing on said first antiferromagnetic layer a pinned layer, a non-magnetic spacer layer, a free layer, and a capping layer, thereby forming a bottom spin valve stack;
on the capping layer, forming an etch mask that defines a pedestal;
using said mask, etching the stack until all unprotected parts of said capping layer, free layer, and spacer layer and a part of said pinned layer have been removed, thereby forming a pedestal, said pedestal having outwardly sloping sidewalls that extend from the capping layer to the unremoved portion of the pinned layer;
on the sidewalls, depositing a decoupling layer that is between about 20 and 50 Angstroms thick;
on the decoupling layer only, depositing a first layer of soft ferromagnetic material;
on said first layer of soft ferromagnetic material only, depositing a second antiferromagnetic layer;
on the second antiferromagnetic layer, depositing a conductive lead layer that overlaps the first soft ferromagnetic and second antiferromagnetic layers and contacts the capping layer;
and
on the capping layer and conductive layer, depositing a second dielectric layer.

9 more elements

Dependencies are inferred from the claim text.

Ferromagnetic/antiferromagnetic bilayer, including decoupler, for longitudinal bias

Life of this patent

Ferromagnetic/antiferromagnetic bilayer, including decoupler, for longitudinal bias

Life of this patent

Abstract

Claims21