Magnetic Element Biasing Structure for Sub-18nm Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Reduced form factor magnetic elements face challenges in achieving reliable magnetic and thermal stability, as well as design and process sensitivity, particularly at widths below 18 nm, due to increased sensitivity to process and design variations and difficulties in providing sufficient demagnetization energy to bring magnetically free layers into a quiescent state.
Innovation Solution
A magnetic stack with a magnetically free layer positioned on an air bearing surface (ABS) is biased to a predetermined magnetization using a biasing structure recessed from the ABS, which maintains reduced shield-to-shield spacing while providing magnetic bias to achieve quiescent states without increasing element thickness or affecting operational characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If the element width is reduced below 18 nm to increase data density, then storage capacity is improved, but magnetic and thermal stability deteriorates
Solution Approach 1:
The patent applies local quality by creating different magnetic environments in different regions of the element. A biasing structure with high coercivity is positioned adjacent to the magnetically free layer, creating a localized magnetic field that provides stability to the free layer's magnetization direction. This allows the element width to be reduced below 18 nm while maintaining magnetic stability through the localized biasing effect.
2Volume of moving object
If the shield-to-shield spacing is reduced to maintain reduced form factor, then element compactness is improved, but providing sufficient demagnetization energy becomes difficult
Solution Approach 1:
The patent resolves this contradiction by utilizing the thickness dimension. The biasing structure is positioned adjacent to the magnetically free layer in the thickness direction, extending along the air bearing surface. This three-dimensional arrangement allows the biasing structure to provide sufficient demagnetization energy and magnetic stability without reducing the shield-to-shield spacing, thereby maintaining compact form factor while ensuring adequate energy for magnetization control.
3Area of moving object
If the element width is reduced below 18 nm, then data density is improved, but sensitivity to process and design variations increases
Solution Approach 1:
The patent implements feedback through the biasing structure that continuously provides a magnetic field to counteract unwanted magnetization changes in the free layer. This magnetic feedback mechanism compensates for variations in element width, coating thickness, and other process parameters, reducing sensitivity to manufacturing variations while maintaining the reduced element width below 18 nm for high data density.
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 configuration enhances magnetic stability and reduces sensitivity to process and design variability, allowing for reliable operation of magnetic elements below 18 nm width by tuning the anisotropies of bias elements and free layers to achieve efficient and stable quiescent magnetization states.
Implementation Method 1
Various embodiments can bias the magnetically free layer to a predetermined magnetization by a biasing structure coupled with the magnetically free layer and positioned distal the ABS
Implementation Method 2
allowing for reliable operation of magnetic elements below 18 nm width by tuning the anisotropies of bias elements and free layers to achieve efficient and stable quiescent magnetization states
Data Source
AI summary
An apparatus can be generally directed to a magnetic stack having a magnetically free layer positioned on an air bearing surface (ABS). The magnetically free layer can be biased to a predetermined magnetization in various embodiments by a biasing structure that is coupled with the magnetically free layer and positioned distal the ABS.