TMR Sensor Layer Structure for Out-of-Plane Field Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing magnetic field sensors with tunnel magnetoresistance (TMR) elements are limited to in-plane detection and struggle to reliably fabricate a reference direction for out-of-plane detection, which is essential for measuring changing magnetic field intensity.
Innovation Solution
A TMR element is fabricated with a specific configuration of antiferromagnetic and ferromagnetic layers, where the magnetization directions alternate by layer, allowing for a consistent reference direction in the z- or -z-direction, enabling out-of-plane detection by controlling the magnetization direction of the free layer to measure changing resistance values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional fabrication methods are used for TMR elements, then in-plane detection is achieved, but out-of-plane detection capability is lost
Solution Approach 1:
The antiferromagnetic material is segmented into multiple layers with alternating magnetization directions. This segmentation allows the top layer's magnetization direction to be independently controlled to establish a reference direction in the z-direction, enabling out-of-plane detection while maintaining reliable directional consistency.
Solution Approach 2:
The invention transitions from in-plane detection (x-y plane) to out-of-plane detection (z-direction) by orienting the reference layer's magnetization direction perpendicular to the x-y plane. This dimensional change is achieved through controlling the top antiferromagnetic layer's magnetization direction during fabrication.
2Reliability
If the reference layer's magnetization direction is not properly controlled, then fabrication is simpler, but out-of-plane detection reliability is compromised
Solution Approach 1:
The alternating magnetization direction structure is built into the antiferromagnetic material during fabrication, with the top layer's magnetization direction pre-established in the z-direction. This preliminary action ensures the reference layer's magnetization direction is correctly oriented before the sensing operation, enabling reliable out-of-plane detection without requiring complex post-fabrication adjustments.
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
Enables reliable out-of-plane detection of magnetic field intensity with measurable changes in resistance, overcoming the limitations of traditional in-plane detection methods.
Implementation Method 1
antiferromagnetic material that includes a plurality of antiferromagnetic layers having magnetization directions alternating by layer between a first direction and a second direction opposite the first direction
Implementation Method 2
tunnel magnetoresistance (TMR) element to sense out-of-plane changes in magnetic field intensity
Data Source
AI summary
In one aspect, a method includes manufacturing a tunneling magnetoresistance (TMR) element to sense out-of-plane changes in magnetic field intensity in a magnetic field. The manufacturing includes depositing a plurality of antiferromagnetic layers having magnetization directions alternating by layer between a first direction and a second direction opposite the first direction. A top layer of the plurality of antiferromagnetic layers has a magnetization direction in the first direction. The manufacturing also includes depositing a ferromagnetic layer directly on the top layer; depositing a first multilayer structure directly on the ferromagnetic layer; depositing a metal layer directly on the first multilayer structure; and depositing a second multilayer structure directly on the metal layer. The ferromagnetic layer, the first multilayer structure, and the second multilayer structure are each parallel to an x-y plane and the first direction is either in a z-direction or in a −z direction.