Magnetic Domain Wall Storage Tracks Using Intermediate Layer Pinning
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Solution Overview
Problem
Conventional nonvolatile information storage devices, such as HDDs and flash memories, face issues with operational reliability, slow reading and writing speeds, short lifespan, and high manufacturing costs, while magnetic domain wall-based storage devices require complex pinning site formation.
Innovation Solution
Magnetic tracks and information storage devices are developed with an intermediate layer having alternately arranged first and second material regions on a substrate, allowing for magnetic domain and domain wall formation without artificial pinning sites, using a seed layer, intermediate layers, and a magnetic layer with specific material compositions and structures to control magnetic domain walls.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If artificial pinning sites are formed to control magnetic domain walls, then magnetic domain wall control is achieved, but manufacturing process complexity increases
Solution Approach 1:
The patent introduces an intermediate layer between the substrate and the magnetic layer. This intermediate layer serves as a mediator that naturally provides pinning sites through its material properties and interface structures, eliminating the need for artificial pinning site formation. The intermediate layer includes a first material region and a second material region with different magnetic anisotropic energies, which together control the magnetic domain wall behavior without requiring complex additional manufacturing steps.
Solution Approach 2:
The patent utilizes changes in magnetic anisotropic energy parameters across different regions of the intermediate layer and magnetic layer. By creating regions with high magnetic anisotropic energy (for stable magnetic domains) and regions with low magnetic anisotropic energy (for movable domain walls), the system achieves natural pinning and control mechanisms through parameter variation rather than structural complexity.
2Reliability
If conventional flash memory is used for nonvolatile storage, then no rotating parts are needed, but reading and writing speeds become slow
Solution Approach 1:
The patent replaces the mechanical rotating disk system of conventional HDDs with a solid-state magnetic domain wall-based storage system. Information is stored and accessed through the movement and positioning of magnetic domain walls in a static magnetic layer, eliminating mechanical moving parts while maintaining fast access speeds comparable to or exceeding conventional flash memory.
3Speed
If magnetic domain wall movement is used for storage, then fast reading and writing speeds are achieved, but manufacturing complexity increases due to pinning site formation
Solution Approach 1:
The patent merges the functions of the substrate, pinning site formation, and magnetic layer into an integrated structure. The intermediate layer is formed as part of the standard magnetic tunnel junction (MTJ) fabrication process, combining multiple functions into a single manufacturing sequence without requiring separate pinning site formation steps.
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 simplifies manufacturing processes and enhances the stability and control of magnetic domain walls, improving data retention and storage capabilities while reducing operational failures and costs.
Implementation Method 1
A magnetic anisotropic energy of the magnetic domain forming region may be between about 2×10³ and about 10⁷ J/m³, inclusive. A magnetic anisotropic energy of the magnetic domain wall forming region may be between about 10 and about 10³ J/m³, inclusive.
Implementation Method 2
Another nonvolatile information storage device uses magnetic domain wall movement of a magnetic material. In these conventional information storage devices, a minute magnetic region—a ferromagnetic substance—is referred to as a magnetic domain.
Implementation Method 3
The magnetic domain wall may be moved by applying a current or an external magnetic field to a magnetic layer.
Data Source
AI summary
Information storage devices and methods of manufacturing the same are provided. A magnetic track of the information storage device includes a magnetic layer in which at least one magnetic domain forming region and at least one magnetic domain wall forming region are alternately disposed in a lengthwise direction. The at least one magnetic domain forming regions has a different magnetic anisotropic energy relative to the at least one magnetic domain wall forming region. An intermediate layer is formed under the magnetic layer. The intermediate layer includes at least one first material region and at least one second material region. Each of the at least one first material regions and the at least one second material regions corresponds to one of the at least one magnetic domain forming regions and the at least one magnetic domain wall forming regions.