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US 8,477,462 B2Granted
CPP device with improved current confining structure and process
AssigneeHeadway Technologies, Inc.
InventorsKunliang Zhang, Min Li, Yue Liu
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Abstract
Plasma nitridation, in place of plasma oxidation, is used for the formation of a CCP layer. Al, Mg, Hf, etc. all form insulating nitrides under these conditions. Maintaining the structure at a temperature of at least 150° C. during plasma nitridation and/or performing post annealing at a temperature of 220° C. or higher, ensures that no copper nitride can form. Additionally, unintended oxidation by molecular oxygen of the exposed magnetic layers (mainly the pinned and free layers) is also avoided.
Claims5
A CCP CPP GMR device, comprising:
- a layer of copper on a magnetically pinned layer that is free of oxygen contamination;
- on said copper layer, an insulating layer of a metallic nitride having an upper surface;
- filaments of pure copper, extending from said copper layer through said insulating metallic nitride layer to said upper surface, serving thereby as a current confining layer;
- a magnetically free layer, that is free of oxygen contamination, on said first upper surface;
- and
- a top electrode on said free layer.
3 more elements
Dependencies are inferred from the claim text.