MRAM Logic Region Stop Layer Thickness Optimization
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Solution Overview
Problem
Current magnetoresistive random access memory (MRAM) devices face issues 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
A semiconductor device with a substrate having a magnetic random access memory (MRAM) region and a logic region, featuring a magnetic tunneling junction (MTJ) and stop layers of different thicknesses, which are formed using a specific process involving metal interconnections, IMD layers, and etching techniques to improve device reliability and breakdown voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a uniform thickness stop layer is used across both MRAM and logic regions, then manufacturing is simplified, but breakdown voltage and reliability are compromised due to the thinner logic region requiring
Solution Approach 1:
The patent applies local quality by varying the stop layer thickness according to the specific requirements of different regions. The MRAM region receives a first thickness while the logic region receives a second, greater thickness. This localized differentiation allows each region to have optimal stop layer thickness for its specific electrical characteristics and breakdown voltage requirements, resolving the contradiction between manufacturing simplicity and reliability.
Solution Approach 2:
The stop layer is segmented into multiple regions with different thicknesses - a first stop layer for the MRAM region and a second stop layer for the logic region. This segmentation allows independent optimization of each region's electrical properties while maintaining a unified manufacturing process flow, thus improving breakdown voltage without significantly complicating manufacturing.
2Measurement precision
If magnetic field sensor technologies such as AMR sensors, GMR sensors, or MTJ sensors are used, then sensing capability is achieved, but chip area increases and cost increases
Solution Approach 1:
The patent makes the MRAM device multi-functional by enabling it to perform both memory storage and magnetic field sensing functions. The same MTJ structure and magnetic layers that provide memory functionality are also utilized for sensing applications. This universality eliminates the need for separate dedicated sensor structures, thereby reducing chip area and cost while maintaining sensing capability.
Solution Approach 2:
The patent merges the memory function and sensing function into a single integrated structure. The MTJ device serves dual purposes: storing data through magnetized states and detecting magnetic fields through resistance changes. By combining these functions in one structure rather than using separate components, the chip area and overall cost are reduced while preserving measurement 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 solution reduces the thickness of the stop layer on the logic region to improve breakdown voltage and overall reliability, addressing the limitations of existing MRAM devices by enhancing their performance and efficiency.
Implementation Method 1
the characterization of utilizing GMR materials to generate different resistance under different magnetized states could also be used to fabricate MRAM devices
Implementation Method 2
the stop layer on the first metal interconnection and the stop layer on the second metal interconnection have different thicknesses
Data Source
AI summary
A semiconductor device includes a substrate having a magnetic random access memory (MRAM) region and a logic region, a first metal interconnection on the MRAM region, a second metal interconnection on the logic region, a stop layer extending from the first metal interconnection to the second metal interconnection, and a magnetic tunneling junction (MTJ) on the first metal interconnection. Preferably, the stop layer on the first metal interconnection and the stop layer on the second metal interconnection have different thicknesses.