Dual CCP Layers in CPP Magnetic Read Heads
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Solution Overview
Problem
Current CCP-CPP GMR designs face uniformity issues due to variations in Cu metal path shapes caused by the conventional PIT/IAO processes, leading to inconsistent resistance and resistance ratio across the wafer.
Innovation Solution
Implementing two separate PIT/IAO processes on each of two AlCu or Al layers, with each process applied for a shorter duration, effectively terminating copper filaments at the interface between dielectric layers, resulting in more uniform copper path formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a single CCP layer with conventional PIT/IAO process is used, then the manufacturing process is simple, but the uniformity of Cu path shapes and device performance is poor
Solution Approach 1:
The single CCP layer is divided into two separate CCP layers (first and second CCP layers), each subjected to its own PIT/IAO process. This segmentation allows independent control and optimization of Cu path formation in each layer, improving overall uniformity while managing complexity through modular processing
Solution Approach 2:
The first CCP layer undergoes PIT/IAO treatment to form initial Cu paths before the second CCP layer is deposited. This preliminary action establishes a foundation that guides and uniformizes the subsequent Cu path formation in the second layer, leading to more consistent final paths
2Manufacturing precision
If longer PIT/IAO process duration is used, then Cu path formation is more complete, but variations in path shapes and performance increase
Solution Approach 1:
The total PIT/IAO treatment time is segmented into two separate processes applied to different layers. Each process runs for a shorter duration, preventing excessive oxidation and Cu migration that cause path shape variations, while achieving complete path formation through the combined effect of both layers
Solution Approach 2:
Each individual PIT/IAO process applies partial oxidation treatment rather than attempting complete path formation in one step. This partial action approach prevents over-oxidation effects that lead to path shape variations, with the second layer completing the formation process
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach significantly improves the uniformity of performance characteristics across the substrate, reducing variations in Cu path shapes and enhancing the overall performance of CCP-CPP GMR devices.
Implementation Method 1
This AlCu layer is then exposed to oxygen by means of the PIT/IAO process to form a current confining path through Al2O3 and Cu segregation
Implementation Method 2
PIT (plasma ion treatment)
Implementation Method 3
Al atoms attract oxygen and form amorphous AlOx. Since Cu is chemically more inert to O2 than Al under the current process conditions, it tends to remain as a Cu metal phase
Implementation Method 4
form a current confining path through Al2O3 and Cu segregation
Data Source
AI summary
An improved CPP magnetic read device whose oxide barrier comprises at least two separate CCP layers is disclosed. These two CCP layers differ in the PIT and IAO treatments that they received relative to the PIT/IAO treatment that would be used when only a single CCP layer is formed.