Series MRAM Pillar Spin Current Structure Retention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In three-dimensional magnetic random-access memory (MRAM) structures, existing technologies face challenges in achieving high data retention while maintaining a lower write current value, particularly when memory elements are connected in series, as this often results in reduced data retention due to conflicting performance parameters like latency and thermal stability.
Innovation Solution
The introduction of a second magnetic memory element with a spin current structure, which has a lower write current value than the first, allows for individual switching and increased retention by incorporating a Precessional Spin Current (PSC) structure that enhances thermal stability and retention without increasing the write current, enabling both elements to have similar retention values even when connected in series.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If memory elements are connected in series in three-dimensional MRAM structures, then device density is improved, but data retention deteriorates due to conflicting performance parameters
Solution Approach 1:
The patent applies local quality by introducing a spin current structure specifically to the second magnetic memory element in the series connection, while the first element maintains conventional structure. This localized modification allows the second element to achieve enhanced thermal stability and retention characteristics without affecting the overall series connection architecture, thereby resolving the contradiction between high density and data retention.
Solution Approach 2:
The patent changes physical parameters by incorporating a spin current structure that modifies the magnetic switching characteristics of the second memory element. This structure enables the element to maintain lower write current requirements while achieving higher retention values, thus changing the performance parameters to simultaneously satisfy both high density and reliable data retention requirements.
2Ease of operation
If a magnetic memory element is designed for lower write current value, then ease of operation is improved, but data retention deteriorates
Solution Approach 1:
The spin current structure is locally applied to the second magnetic memory element to fundamentally alter its switching characteristics. This localized enhancement allows the element to achieve both lower write current operation and higher data retention simultaneously, breaking the traditional trade-off between ease of operation and reliability.
Solution Approach 2:
The spin current structure acts as a composite enhancement to the conventional magnetic memory element, combining conventional magnetic layers with spin current generation and detection mechanisms. This composite structure enables dual functionality of low-power switching and high-retention storage within the same element.
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 enables higher retention values for the overall magnetic memory system while maintaining a lower write current, overcoming the limitations of reduced data retention associated with lower latency memory elements, thus ensuring robust and efficient data storage.
Implementation Method 1
The switching of the MTJ element between high and low resistance states results from electron spin transfer. When electrons flow through a magnetized layer, the spin orientations of the electrons become aligned so that there is a net aligned orientation of electrons flowing through the magnetic layer
Implementation Method 2
incorporating a Precessional Spin Current (PSC) structure that enhances thermal stability and retention without increasing the write current
Implementation Method 3
The first magnetic layer, which can be referred to as a reference layer, has a magnetization that is fixed in a direction that is perpendicular to that plane of the layer. The second magnetic layer, which can be referred to as a magnetic free layer, has a magnetization that is free to move
Implementation Method 4
Magnetic Random-Access Memory (MRAM) is a non-volatile data memory technology that stores data using magnetoresistive cells such as Magnetoresistive Tunnel Junction (MTJ) cells. MTJ elements include first and second magnetic layers that are separated by a thin, non-magnetic layer such as a tunnel barrier layer
Data Source
AI summary
A magnetic memory pillar structure having a plurality of magnetic memory elements connected in series, wherein switching of individual memory elements in the pillar structure can be accomplished based on differing switching current values of the magnetic memory elements. Each of the plurality of memory elements advantageously have similar retention values in spite of the different switching current values (latency values) as a result of a precessional spin current injection structure provided in the memory element or memory elements having the lower switching current value.