Magnetic Memory Cells with Opposite Magnetization Directions
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Solution Overview
Problem
Current memory devices face challenges in achieving a balance between operating speed and non-volatility, with DRAM offering high speeds but being volatile and flash memory providing non-volatility but with lower speeds and higher voltage requirements.
Innovation Solution
A magnetic memory device design featuring first and second magnetic memory cells with different stacking orders of pinned, tunnel insulating, and free magnetic layers, and a common source line, allowing for binary data storage through resistance comparison and magnetization direction manipulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If DRAM is used for high operating speed, then operating speed is improved, but data loss occurs when power is lost or turned off
Solution Approach 1:
The patent changes the fundamental operating parameter from electrical charge storage (DRAM) to magnetization state storage (magnetic memory). By utilizing the magnetic properties of materials and their ability to maintain magnetization states without power, the system achieves both high operating speed and non-volatility simultaneously
2Reliability
If flash memory is used for non-volatility, then data retention is improved, but operating speed decreases and operating voltage increases
Solution Approach 1:
The patent changes the storage mechanism from charge trapping in floating gate structures (flash) to magnetization switching in magnetic tunnel junctions. This parameter change enables faster write operations and lower operating voltages while maintaining non-volatile data retention
Solution Approach 2:
The patent replaces the electrical field-based charge storage mechanism with a magnetic field-based magnetization storage mechanism. This substitution enables faster switching speeds and reduced power consumption while achieving non-volatility
3Productivity
If magnetization directions are made opposite in adjacent memory cells, then data storage efficiency is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent introduces asymmetry in the stacking order of magnetic layers between adjacent memory cells. By deliberately designing different stacking sequences (e.g., PFTJ vs. RMTJ structures), the patent achieves opposite magnetization directions and improved data storage efficiency while providing clear structural differentiation that can be manufactured with standard precision
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 magnetic memory device achieves improved operating speed and efficient data storage with reduced voltage requirements, addressing the limitations of existing memory technologies.
Implementation Method 1
The magnetic memory device is a memory device which operates based on a change of a resistance state according to a magnetization direction of a magnetic body
Implementation Method 2
operates based on a change of a resistance state according to a magnetization direction of a magnetic body
Implementation Method 3
a tunnel insulating layer therebetween
Data Source
AI summary
A magnetic memory device includes first and second magnetic memory cells coupled to first and second bit lines, respectively. The first and second magnetic memory cells respectively include a pinned magnetic layer, a free magnetic layer, and a tunnel insulating layer therebetween. Respective stacking orders of the pinned magnetic layer, the tunnel insulating layer, and the free magnetic layer are different in the first and second magnetic memory cells. The magnetic memory device further includes at least one transistor that is configured to couple the first and second magnetic memory cells to a common source line. Related methods of operation are also discussed.