AMR Sensor Fabrication via Inverted Barber Pole Sequence
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Solution Overview
Problem
Conventional anisotropic magnetoresistive (AMR) sensors face challenges in fabrication efficiency and cost due to contamination risks during the process, particularly when dealing with materials like nickel-iron, which are difficult to handle in clean room environments, and there is a need for improved sensor architectures and techniques for high-performance operation.
Innovation Solution
The AMR sensor design involves forming the AMR element above the barber pole structures, using a seed layer and multiple capping layers to protect materials and prevent contamination, with the capping materials such as tantalum, ruthenium, and titanium, and employing specific etching techniques to fabricate the sensor layers efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional fabrication processes are used to create AMR sensors, then manufacturing simplicity is maintained, but contamination occurs during fabrication due to exposure to sensitive materials like nickel-iron
Solution Approach 1:
The patent applies preliminary action by forming the AMR element above the barber pole structures during fabrication, rather than the conventional approach of forming barber poles above the AMR element. This sequence change prevents contamination of the AMR material during standard fabrication processes, as the sensitive AMR layer is positioned and protected before any potential contaminating steps occur.
Solution Approach 2:
The patent uses capping layers as intermediary protective barriers between the AMR element and the fabrication environment. These capping layers isolate the sensitive AMR material from potential contaminants during handling and processing, enabling standard fabrication techniques to be used without direct exposure to the nickel-iron AMR material.
2Reliability
If the AMR element is formed above the barber pole structures, then contamination risks are reduced, but fabrication steps and material layers increase
Solution Approach 1:
The patent achieves multi-functionality by designing the capping layers to serve multiple purposes: they protect the AMR element from contamination, provide structural support during fabrication, and enable the use of standardized fabrication processes. This universal approach allows a single structural element to address multiple concerns, improving ease of manufacture despite the additional layer.
Solution Approach 2:
The patent inverts the conventional fabrication sequence by forming the AMR element above the barber pole structures rather than below them. This inversion fundamentally changes the fabrication dynamics, allowing standard processes to be applied without contaminating the sensitive AMR material, thereby improving ease of manufacture while enhancing material protection.
3Ease of manufacture
If standardized device fabrication processes are used, then manufacturing cost is reduced, but contamination exposure to sensitive materials increases
Solution Approach 1:
The patent employs capping layers as intermediary protective barriers that enable standardized fabrication processes to be used without direct exposure to sensitive AMR materials. These capping layers act as mediators between the standardization benefits and contamination risks, allowing industrial-scale manufacturing techniques to be applied while maintaining material purity.
Solution Approach 2:
The patent applies preliminary action by positioning the AMR element above the barber pole structures and applying protective capping layers before any standardized fabrication steps occur. This preliminary protective measure ensures that when standardized processes are applied, the sensitive AMR material is already isolated and protected, enabling cost-effective manufacturing without contamination.
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 reduces contamination risks, enhances fabrication efficiency, and allows for the use of standardized device fabrication processes, resulting in improved performance and cost-effectiveness of AMR sensors by isolating sensitive materials from the initial fabrication environment.
Implementation Method 1
the upper portion of the barber poles to protect other materials in the AMR sensor from exposure to the metal of the lower portion of the barber poles
Implementation Method 2
Magnetoresistance is the ability of a material to change its electrical resistance when exposed to an external magnetic field
Implementation Method 3
Anisotropic magnetoresistance (AMR) is a form of magnetoresistance where the change in resistance of a material depends upon the angle between the direction of magnetization and the direction of current flow in the material
Data Source
AI summary
Novel anisotropic magneto-resistive (AMR) sensor architectures and techniques for fabricating same are described. In some embodiments, AMR sensors having barber pole structures disposed below corresponding AMR sensing elements are provided. AMR sensors having segmented AMR sensing elements are also described. Fabrication techniques that can be used to fabricate such sensors are also described. Fabrication techniques are also described that can reduce the risk of contamination during AMR sensor fabrication.