US 2003/0189801 A1 · Patterned exchange bias GMR using metallic buffer layer

Abstract

In magnetic read heads based on bottom spin valves the preferred structure is for the longitudinal bias layer to be in direct contact with the free layer. Such a structure is very difficult to manufacture. The present invention overcomes this problem by introducing an extra layer between the bias electrodes and the free layer. This layer protects the free layer during processing but is thin enough to not interrupt exchange between the bias electrodes and the free layer. In one embodiment this is a layer of copper about 5 Å thick and parallel exchange is operative. In other embodiments ruthenium is used to provide antiparallel exchange between the bias electrode and the free layer. A process for manufacturing the structure is also described.

Claims35

Dependent claims

A magnetic read head, comprising:

a GMR stack whose topmost layer is a magnetically free layer;
on said free layer, a buffer layer having a trapezoidal cross-section whereby said buffer layer further comprises a central area, of uniform thickness and having a width, that has two opposing parallel edges and, abutting said edges, opposing side areas whose thickness tapers off uniformly to zero over a distance from each of said edges;
on said buffer layer, excluding said central area, and on said free layer, a soft ferromagnetic layer;
on said soft ferromagnetic layer, an antiferromagnetic layer;
on said antiferromagnetic layer, a conductive lead layer;
and
on all of said central area, a cap layer.

4 more elements

Dependencies are inferred from the claim text.

Patterned exchange bias GMR using metallic buffer layer

Life of this patent

Patterned exchange bias GMR using metallic buffer layer

Life of this patent

Abstract

Claims35