MTJ Channel Layer Layout for Low-Power SOT MRAM Switching
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Solution Overview
Problem
Current magnetoresistive random access memory (MRAM) devices face challenges such as high chip area, high cost, high power consumption, and sensitivity to temperature variations, limiting their effectiveness in magnetic field sensing applications.
Innovation Solution
The fabrication of a semiconductor device involves forming a magnetic tunneling junction (MTJ) on a substrate, surrounded by inter-metal dielectric layers, with a channel layer electrically connecting the MTJ to metal interconnections, utilizing a spin orbit torque (SOT) approach to switch magnetic moments through an in-plane current, isolating the read/write path and enhancing device endurance and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional spin torque transfer (STT) approach is used to switch magnetic moments, then write speed can be achieved, but power consumption increases and device endurance decreases
Solution Approach 1:
The patent segments the current path into two separate paths: a write current path flowing through the channel layer to generate spin-orbit torque, and a read current path flowing through the magnetic tunneling junction. This segmentation allows the write operation to use spin-orbit torque with lower power consumption while maintaining write speed, and the read operation to use TMR effect with high stability.
Solution Approach 2:
The patent introduces a channel layer as an intermediary component between the metal interconnection and the magnetic tunneling junction. This channel layer serves as the mediator that converts charge current into spin current through the spin Hall effect or Rashba effect, enabling low-power magnetic moment switching without directly passing current through the MTJ.
2Measurement precision
If conventional magnetic field sensor technologies are used, then sensing capability can be achieved, but chip area increases and cost increases
Solution Approach 1:
The patent creates a multi-functional device structure where the magnetic tunneling junction serves dual purposes: as a memory element for data storage and as a sensing element for magnetic field detection. The same MTJ structure utilizes TMR effect for both read operations in MRAM and magnetic field sensing, eliminating the need for separate sensor components and reducing chip area.
Solution Approach 2:
The patent merges the memory function and sensing function into a single integrated structure. The magnetic tunneling junction is used both for storing data bits in the MRAM cell and for detecting magnetic fields, combining what were traditionally separate functions into one compact component that reduces overall chip area.
3Measurement precision
If conventional magnetic field sensor technologies are used, then sensing capability can be achieved, but device reliability decreases due to temperature sensitivity
Solution Approach 1:
The patent implements compensation mechanisms that use feedback principles to counteract temperature effects. By monitoring resistance changes and applying compensation algorithms, the device maintains stable sensing performance across temperature variations, improving reliability while preserving sensing capability.
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 reduces power consumption, improves device endurance, and enhances read stability by using the spin orbit torque effect to switch magnetic moments, outperforming conventional spin torque transfer (STT) devices in terms of write speed and endurance.
Implementation Method 1
utilizing a spin orbit torque (SOT) approach to switch magnetic moments through an in-plane current
Implementation Method 2
The physical definition of such effect is defined as a variation in resistance obtained by dividing a difference in resistance under no magnetic interference by the original resistance
Data Source
AI summary
A method for fabricating a semiconductor device includes the steps of: forming a magnetic tunneling junction (MTJ) on a substrate; forming a first inter-metal dielectric (IMD) layer around the MTJ; forming a first metal interconnection adjacent to the MTJ; forming a stop layer on the first IMD layer; removing the stop layer to form an opening; and forming a channel layer in the opening to electrically connect the MTJ and the first metal interconnection.