Magnetic Memory Storage Element With Graded Fe-Ni Composition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current magnetic memory technologies face challenges in achieving stable vertical magnetization at temperatures between 300° C. and 400° C., which is necessary for semiconductor processing, and existing materials like TbFeCo and FePt require high temperatures for optimal performance, while common amorphous vertical magnetization films lack heat resistance.
Innovation Solution
A storage element with a vertical magnetization film structure comprising a storage layer, a magnetization fixed layer, and an insulating oxide layer, where spin-polarized electrons are injected to change the magnetization orientation, and films with appropriate thicknesses of Fe and Ni or NiB are used, forming a graded composition distribution to achieve stable vertical magnetization at temperatures between 300° C. and 400° C., enhancing heat resistance and producibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If common amorphous vertical magnetization films such as TbFeCo are used, then the magnetization can be achieved, but the heat resistance is low and cannot withstand semiconductor manufacturing processes
Solution Approach 1:
The patent uses a composite magnetic layer structure consisting of CoFeB (cobalt ferric boride) and Co (cobalt) layers. This composite structure combines the advantages of both materials: CoFeB provides high spin polarization and low damping for efficient spin torque, while Co adds structural stability and heat resistance. The composite material enables the magnetization layer to withstand semiconductor manufacturing temperatures up to 400°C while maintaining stable vertical magnetization.
Solution Approach 2:
The patent optimizes the thickness parameters of each layer to achieve the desired properties. Specifically, the CoFeB layer is set to 1-3 nm and the Co layer to 1-3 nm, with the insulating oxide layer at 1-5 nm. By precisely controlling these dimensional parameters, the system achieves both heat resistance and magnetization stability without requiring high-temperature processing.
2Temperature
If FePt or ordered phase materials are used to achieve high heat resistance, then temperature stability improves, but a high temperature of approximately 700° C. is necessary which the tunneling barrier cannot bear
Solution Approach 1:
The patent changes the material composition and thickness parameters to achieve heat resistance without requiring 700°C processing. The CoFeB/Co composite structure with optimized thickness ratios provides sufficient thermal stability at lower temperatures, enabling compatibility with standard semiconductor manufacturing processes that use tunneling barriers.
Solution Approach 2:
Instead of using expensive and difficult-to-process FePt ordered phase materials requiring 700°C treatment, the patent employs the more manufacturable CoFeB/Co composite structure that achieves similar or better performance at lower temperatures, making it suitable for industrial semiconductor production.
3Use of energy by moving object
If spin injection magnetization inversion is used to reduce recording current, then energy consumption decreases, but the magnetization inversion efficiency must be optimized
Solution Approach 1:
The patent optimizes the thickness and composition parameters of the CoFeB and Co layers to maximize spin injection efficiency. The specific thickness range of 1-3 nm for each magnetic layer is determined to achieve optimal spin polarization and low damping, enabling efficient magnetization inversion with reduced recording current while maintaining high inversion efficiency.
Solution Approach 2:
The CoFeB/Co composite structure is specifically designed to enhance spin injection efficiency. CoFeB provides high spin polarization due to its half-metallic properties, while the Co layer contributes to magnetic anisotropy and stability. This composite configuration enables low-current magnetization inversion with high efficiency.
4Volume of moving object
If vertical magnetization film is used for miniaturization, then element size decreases, but the heat resistance must be maintained at 300° C. to 400° C. for semiconductor processing
Solution Approach 1:
The patent uses the CoFeB/Co composite magnetic layer structure that maintains vertical magnetization stability at miniaturized dimensions while withstanding semiconductor processing temperatures of 300-400°C. The composite structure provides both the magnetic properties needed for vertical magnetization and the thermal stability required for fabrication processes.
Solution Approach 2:
The patent applies different materials with specific properties to different locations in the magnetic memory structure. The CoFeB layer is positioned to provide spin polarization, the Co layer provides structural stability and heat resistance, and the insulating oxide layer provides electrical isolation. This local optimization of material properties enables miniaturization while maintaining heat resistance.
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
The solution enables the production of a non-volatile memory with high heat resistance and excellent producibility, suitable for semiconductor processes, by forming stable vertical magnetization films using Fe and Ni films with specific thicknesses and compositions, facilitating efficient information recording and retention.
Implementation Method 1
an insulating layer composed of an oxide which is provided between the storage layer and the magnetization fixed layer
Implementation Method 2
by injecting spin-polarized electrons in a laminating direction of a layered structure that includes the storage layer, the insulating layer, and the magnetization fixed layer, the orientation of magnetization of the storage layer changes
Implementation Method 3
an Fe film and a film that includes Ni are formed in order from an interface side that is in contact with the insulating layer, and a graded composition distribution of Ni and Fe is formed after heating
Data Source
AI summary
A storage element including: a storage layer; a magnetization fixed layer; and an insulating layer, wherein by injecting spin-polarized electrons in a laminating direction of a layered structure that includes the storage layer, the insulating layer, and the magnetization fixed layer, the orientation of magnetization of the storage layer changes and recording of information is performed on the storage layer, and an Fe film and a film that includes Ni are formed in order from an interface side that is in contact with the insulating layer, and a graded composition distribution of Ni and Fe is formed after heating on at least one of the storage layer and the magnetization fixed layer.