MRAM MTJ Blocking Layer Against Hydrogen Penetration
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Solution Overview
Problem
Existing MRAM devices face issues such as high chip area, high cost, high power consumption, limited sensitivity, and susceptibility to temperature variations, which current fabrication methods have not adequately addressed.
Innovation Solution
A method for fabricating MRAM devices involving the formation of a blocking layer made of metal or dielectric material to shield MTJs from hydrogen gas penetration, using a single or dual damascene process for metal interconnects, and employing specific materials like copper, tungsten, and silicon oxide for improved electrical connectivity and magnetic performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional fabrication methods are used for MRAM devices, then manufacturing process is simpler, but hydrogen gas penetrates MTJs causing degraded magnetic performance
Solution Approach 1:
A blocking layer comprising a first blocking layer and a second blocking layer is introduced between the hydrogen gas environment and the MTJ structure. The first blocking layer is positioned between the hydrogen gas and the top electrode of the MTJ, while the second blocking layer is positioned between the hydrogen gas and the bottom electrode of the MTJ. This intermediary blocking layer structure prevents hydrogen gas from penetrating into the MTJ, thereby maintaining magnetic performance while allowing conventional fabrication processes to continue.
2Reliability
If blocking layer is added to prevent hydrogen gas penetration, then magnetic performance is protected, but fabrication process becomes more complex
Solution Approach 1:
The blocking layers are formed prior to subsequent fabrication steps that may expose the device to hydrogen gas. By establishing the protective blocking layer structure in advance, the MTJ is pre-protected from hydrogen gas penetration during later manufacturing processes, ensuring device reliability without requiring complex post-fabrication modifications.
3Reliability
If existing MRAM device structures are used, then chip area is smaller, but sensitivity is limited and power consumption is high
Solution Approach 1:
The blocking layer structure is selectively applied only to the MTJ regions where hydrogen gas protection is critical, rather than covering the entire chip area. This localized approach provides the necessary protection for magnetic performance while minimizing the additional area consumed by the blocking layers, thus maintaining compact device dimensions.
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 hydrogen gas impact on magnetic performance, thereby enhancing device reliability and reducing chip area, cost, and power consumption while maintaining sensitivity, addressing the limitations of existing technologies.
Implementation Method 1
a blocking layer made of metal or dielectric material to shield MTJs from hydrogen gas penetration
Implementation Method 2
the characterization of utilizing GMR materials to generate different resistance under different magnetized states
Data Source
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AI summary
A method for fabricating semiconductor device includes the steps of: providing a substrate (12) having a logic region (16) and a magnetoresistive random access memory (MRAM) region, forming a magnetic tunneling junction, MTJ (34), on the MRAM region (14), forming a metal interconnection (26, 32, 48, 54) on the MTJ (34), forming a dielectric layer (64, 66, 68) on the metal interconnection (26, 32, 48, 54), patterning the dielectric layer (64, 66, 68) to form openings (70), and forming the blocking layer (60) on the patterned dielectric layer and the metal interconnection (26, 32, 48, 54) and into the openings (70); wherein the blocking layer (60) comprises a second dielectric layer, particularly silicon carbide, silicon carbon nitride, SiCN, or silicon carbo-oxynitride, SiCON.