US 6,888,703 B2 · Multilayered structures comprising magnetic nano-oxide layers for current perpindicular to plane GMR heads

Abstract

Nano-oxide based current-perpendicular-to-plane (CPP) magnetoresistive (MR) sensor stacks are provided, together with methods for forming such stacks. Such stacks have increased resistance and enhanced magnetoresistive properties relative to CPP stacks made entirely of metallic layers. Said enhanced properties are provided by the insertion of magnetic nano-oxide layers between ferromagnetic layers and non-magnetic spacer layers, whereby said nano-oxide layers increase resistance and exhibit spin filtering properties. CPP sensor stacks of various types are provided, all having nano-oxide layers formed therein, including the spin-valve type and the synthetic antiferromagnetic pinned layer spin-valve type. Said stacks can also be formed upon each other to provide laminated stacks of different types.

Claims10

Dependent claims

A magnetic nano-oxide based current-perpendicular-to-plane (CPP) magnetoresistive (MR) sensor stack having increased perpendicular resistance and enhanced magnetoresistive properties, comprising:

a substrate;
a first metallic, non-magnetic spacer layer formed upon said substrate;
a first ferromagnetic tri-layer, comprising two strongly coupled ferromagnetic layers separated by a first magnetic nano-oxide layer, formed upon said first metallic, non-magnetic spacer layer;
a second metallic, non-magnetic spacer layer formed on said first ferromagnetic tri-layer;
a second ferromagnetic tri-layer, comprising two strongly exchange coupled ferromagnetic layers separated by a second magnetic nano-oxide layer, formed upon said second metallic, non-magnetic spacer layer;
a third metallic, non-magnetic spacer layer formed upon said second ferromagnetic tri-layer and wherein said first and second nano-oxide layers are formed of materials that differentiate resistively between spin-up and spin-down electrons and are formed with sufficient thickness to eliminate pinholes.

3 more elements

A method of forming a magnetic nano-oxide based current-perpendicular-to-plane (CPP) magnetoresistive (MR) sensor stack having increased perpendicular resistance and enhanced magnetoresistive properties, comprising:

providing a substrate;
forming upon said substrate a first metallic, non-magnetic spacer layer;
forming upon said first metallic, non-magnetic spacer layer a first ferromagnetic tri-layer, comprising two strongly coupled ferromagnetic layers separated by a first magnetic nano-oxide layer;
forming upon said first ferromagnetic tri-layer a second metallic, non-magnetic spacer layer;
forming upon said second metallic, non-magnetic spacer layer a second ferromagnetic tri-layer, comprising two strongly exchange coupled ferromagnetic layers separated by a second magnetic nano-oxide layer;
forming upon said second ferromagnetic tri-layer a third metallic, non-magnetic spacer layer and wherein said first and second nano-oxide layers are formed of materials that differentiate resistively between spin-up and spin-down electrons and are formed with sufficient thickness to eliminate pinholes.

3 more elements

Dependencies are inferred from the claim text.

Multilayered structures comprising magnetic nano-oxide layers for current perpindicular to plane GMR heads

Life of this patent

Multilayered structures comprising magnetic nano-oxide layers for current perpindicular to plane GMR heads

Life of this patent

Abstract

Claims10