SOT-MTJ Memory Cell Structure for Compact Magnetic Sensing
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Solution Overview
Problem
Existing magnetoresistive random access memory (MRAM) technologies face issues such as high chip area, high cost, high power consumption, limited sensitivity, and susceptibility to temperature variations, which need to be addressed for improved performance.
Innovation Solution
A semiconductor device fabrication method involving the formation of a spin orbit torque (SOT) layer, magnetic tunneling junction (MTJ), and multiple cap and inter-metal dielectric (IMD) layers, with specific materials and processes to optimize device structure and functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional magnetic field sensor technologies (AMR sensors, GMR sensors, MTJ sensors) are used, then magnetic field sensing function is achieved, but chip area is large and cost is high
Solution Approach 1:
The patent combines the magnetic field sensing function with MRAM memory cells into a single integrated structure. The MTJ device serves dual purposes as both memory element and magnetic field sensor, eliminating the need for separate sensor components and reducing overall chip area.
Solution Approach 2:
The magnetic tunneling junction (MTJ) device is designed to perform multiple functions: it acts as both a non-volatile memory storage element and a magnetic field sensor. This multi-functionality allows the same structure to replace both MRAM and separate magnetic field sensors, reducing chip area and cost.
2Measurement precision
If conventional magnetic field sensor technologies are used, then magnetic field sensing function is achieved, but power consumption is high
Solution Approach 1:
The MTJ-based sensor utilizes the magnetoresistance effect inherent in its memory structure to detect magnetic fields passively. The device leverages its own magnetic tunneling properties for sensing without requiring additional active sensing circuits or high power consumption, achieving self-service functionality.
3Measurement precision
If conventional magnetic field sensor technologies are used, then magnetic field sensing function is achieved, but sensitivity is limited and temperature sensitivity is high
Solution Approach 1:
The patent utilizes the magnetoresistance (MR) effect and giant magnetoresistance (GMR) effect to achieve high sensitivity magnetic field detection. By changing the resistance state of the MTJ based on magnetic field variations, the device achieves enhanced sensitivity while the non-volatile memory特性 provides stability against temperature variations.
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 proposed method and device structure enhance MRAM performance by reducing chip area, lowering costs, and improving sensitivity and temperature stability, offering a more efficient and reliable memory solution.
Implementation Method 1
first forming a spin orbit torque (SOT) layer on a substrate
Implementation Method 2
the characterization of utilizing GMR materials to generate different resistance under different magnetized states
Data Source
AI summary
A method for fabricating a semiconductor device includes the steps of first forming a spin orbit torque (SOT) layer on a substrate, forming a magnetic tunneling junction (MTJ) on the SOT layer, forming a first cap layer on the MTJ, forming a first inter-metal dielectric (IMD) layer on the first cap layer, forming a second cap layer on the first cap layer and the first IMD layer, forming a second IMD layer on the first cap layer, the first IMD layer, and the second cap layer, and then planarizing the first cap layer, the first IMD layer, the second cap layer, and the second IMD layer.