Magnetic Memory Cell With Side Magnetic Layer For Write Current Reduction
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Solution Overview
Problem
Current magnetoresistive random access memory (MRAM) technologies face challenges in reducing the write current required for data storage, which affects power consumption and storage density, due to limitations in the high-frequency magnetic field assist effect and the inversion threshold of magnetization in existing magnetic memory cells.
Innovation Solution
The integration of a fourth magnetic layer on the side surface of the magnetoresistive effect element via an insulating film, which collects and amplifies the high-frequency magnetic field generated by the rotation layer, reducing the write current by enhancing the high-frequency magnetic field assist effect and synchronizing the magnetic field with the precession movement of the storage layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the high-frequency magnetic field assist effect is used to reduce write current, then power consumption is reduced, but the inversion threshold of magnetization remains too high to achieve sufficient current reduction
Solution Approach 1:
The patent introduces a fourth magnetic layer positioned on the side surface of the magnetoresistive effect element, adding a spatial dimension to the magnetic field generation. This side-surface placement allows the magnetic field to act on the storage layer from a different geometric perspective, enhancing the assist effect and enabling further reduction of write current while maintaining reliable magnetization inversion.
Solution Approach 2:
The patent combines multiple magnetic field generation mechanisms by integrating the rotation layer within the magnetoresistive effect element and the fourth magnetic layer on its side surface. Both layers generate high-frequency magnetic fields that work synergistically to assist magnetization inversion, merging their effects to overcome the insufficient assist effect of single-layer configurations.
2Reliability
If the size of the select transistor is increased to supply higher write current, then data storage capability is improved, but chip size increases
Solution Approach 1:
The patent changes the physical parameters of the magnetic memory cell by introducing the fourth magnetic layer with specific magnetic properties on the side surface. This parameter change enables more efficient magnetization inversion through enhanced high-frequency magnetic field assist effect, allowing data storage capability to be maintained or improved while using smaller select transistors and reducing chip size.
3Use of energy by moving object
If the write current through the magnetoresistive effect element is reduced, then power consumption decreases, but the magnetic field assist effect is insufficient without additional structures
Solution Approach 1:
The patent adds structural complexity in a specific spatial configuration by placing the fourth magnetic layer on the side surface of the magnetoresistive effect element. This three-dimensional arrangement creates an additional magnetic field pathway that enhances the assist effect, allowing write current reduction while the added structural complexity is localized and geometrically efficient.
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 reduces the write current through the magnetoresistive effect element, leading to lower power consumption and improved storage density without increasing the size of the select transistor, thereby contributing to chip size reduction and enhanced storage capabilities.
Implementation Method 1
a fourth magnetic layer which is provided on the side surface of the magnetoresistive effect element via an insulating film, collects a magnetic field generated from the end of the third magnetic layer
Implementation Method 2
The magnetoresistive effect element includes the ferromagnetic layer which is invariable in magnetization direction (hereinafter referred to as a magnetization invariable layer or reference layer), the ferromagnetic layer which is variable in magnetization direction (hereinafter referred to as a magnetization free layer or storage layer)
Implementation Method 3
the frequency of the magnetic field synchronizes with the precession movement of the storage layer
Data Source
AI summary
According to one embodiment, a magnetic memory according to an embodiment includes a magnetoresistive effect element and a fourth magnetic layer which is provided on the side surface of the magnetoresistive effect element via an insulating film. The magnetoresistive effect element has a first magnetic layer of which the magnetization direction is variable, a second magnetic layer of which the magnetization direction fixed, a third magnetic layer of which the magnetization direction parallel to a film plane is variable, and an intermediate layer between the first magnetic layer and the second magnetic layer. The fourth magnetic layer collects a magnetic field generated from the end of the third magnetic layer.