Method of making a tunnel junction sensor with a smooth interface between a pinned or free layer and a barrier layer
AssigneeInternational Business Machines Corporation
InventorMustafa Pinarbasi
Life of this patent
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Abstract
A method of making provides a smooth surface of a pinned or free layer interfacing a barrier layer in a tunnel junction sensor wherein the smooth surface is an oxidized monolayer of the pinned or free layer. After sputter depositing the pinned or free layer the layer is subjected to an oxygen (O2) atmosphere which is extremely low for a very short duration. In a preferred embodiment of the invention a partial thickness of the barrier layer is provided with a smooth surface by the same process after which a remainder thickness of the barrier layer is deposited and the barrier layer is exposed to oxygen (O2) to form an oxide of the deposited metal.
Claims11
A method of making a magnetic read head which has an air bearing surface (ABS), comprising the steps of:
- making a tunnel junction sensor including the steps of:
- forming a ferromagnetic pinned layer structure with a magnetic moment;
- forming an antiferromagnetic pinning layer exchange coupled to the pinned layer structure for pinning the magnetic moment of the pinned layer structure;
- forming a ferromagnetic free layer structure with a magnetic moment;
- forming a nonmagnetic electrically insulative baffler layer between the free layer structure and the pinned layer structure;
- and
- forming at least one of the pinned layer structure or the free layer structure with a first oxidized monolayer that interfaces the barrier layer;
- the step of forming the barrier layer including the steps of:
- forming at least a first portion of the baffler layer in an unoxidized state;
- forming said at least said first portion of the baffler layer with a second oxidized monolayer;
- forming at least a second portion of the barrier layer in an unoxidized state on said second oxidized monolayer of said at least said first portion of the barrier layer;
- and
- oxidizing said at least first and second portions of the barrier layer.
A method of making a magnetic head assembly having an air bearing surface (ABS), comprising the steps of:
- making a write head including the steps of:
- forming ferromagnetic first and second pole piece layers that have a yoke portion between a pole tip portion and a back gap portion;
- forming a nonmagnetic write gap layer located between the pole tip portions of the first and second pole piece layers;
- forming an insulation stack with at least one coil layer embedded therein between the yoke portions of the first and second pole piece layers;
- and
- connecting the back gap portions of the first and second pole piece layers;
- and
- making a read head including the steps of:
- forming a first shield layer;
- forming a tunnel junction sensor located between the first shield layer and the first pole piece layer;
- making the tunnel junction sensor including the steps of:
- forming a ferromagnetic pinned layer structure that has a magnetic moment;
- forming an antiferromagnetic pinning layer structure exchange coupled to the pinned layer structure for pinning the magnetic moment of the pinned layer structure;
- forming a ferromagnetic free layer structure which has a magnetic moment;
- and
- forming a nonmagnetic electrically insulative barrier layer between the free layer structure and the pinned layer structure;
- forming at least one of the pinned layer structure or the free layer structure with a first oxidized monolayer that is adjacent the barrier layer;
- the step of forming the barrier layer includes the steps of:
- forming at least a first portion of the barrier layer in an unoxidized state;
- forming said at least said first portion of the barrier layer with a second oxidized monolayer;
- forming at least a second portion of the barrier layer in an unoxidized state on said second oxidized monolayer of said at least said first portion of the barrier layer;
- and
- oxidizing said at least first and second portions of the barrier layer.
Dependencies are inferred from the claim text.