MRAM Seal Layer Prevents Etching Damage
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Solution Overview
Problem
Existing MRAM technologies face issues with short circuits and structural damage during the formation of conductive patterns, primarily due to excess etching and spacer layer shrinkage, which affect the performance and reliability of magnetoresistive random access memory devices.
Innovation Solution
A seal layer is introduced to protect the MRAM structure by covering only one region, preventing exposure and short circuits between the magnetic tunneling junction and conductive patterns, while maintaining the integrity of the MRAM structure during subsequent processing steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If excess etching is performed during the formation of conductive patterns, then the conductive patterns can be formed more completely, but the MRAM structure becomes exposed and vulnerable to damage
Solution Approach 1:
A seal layer is formed over the MRAM structure before the conductive pattern formation process begins. This seal layer serves as a protective barrier that prevents excess etching from damaging the MRAM structure while allowing the conductive patterns to be formed completely. The seal layer is removed after the conductive patterns are formed, having fulfilled its protective function.
Solution Approach 2:
The seal layer acts as an intermediary protective element between the etching process and the MRAM structure. It mediates the conflict by providing a sacrificial layer that can be etched away along with the dielectric layers, protecting the underlying MRAM structure from direct exposure to the etching process.
2Ease of manufacture
If the spacer layer is allowed to shrink during processing, then the manufacturing process is simpler, but the MRAM structure becomes exposed and short circuits may occur
Solution Approach 1:
The seal layer is formed in advance to cover the MRAM structure before any processing that might cause spacer layer shrinkage. This preliminary protective action ensures that even if the spacer layer shrinks during subsequent processing steps, the MRAM structure remains protected and covered.
Solution Approach 2:
The seal layer provides a cushioning protective effect against the potential harmful consequences of spacer layer shrinkage. By having this protective layer in place beforehand, the patent prevents the exposure of the MRAM structure that would otherwise occur due to spacer layer shrinkage, avoiding short circuits.
3Productivity
If no seal layer is used, then the manufacturing process is simpler and faster, but short circuits occur between the MTJ and conductive patterns
Solution Approach 1:
The seal layer serves as an intermediary protective barrier during the conductive pattern formation process. It prevents direct contact between the conductive patterns and the MTJ structure, eliminating short circuits. The seal layer is removed after serving its protective function, allowing the device to maintain its intended functionality.
Solution Approach 2:
The seal layer is introduced as a temporary protective element that is extracted (removed) after fulfilling its protective function. This approach allows the manufacturing process to proceed with the necessary etching and patterning steps while protecting the MRAM structure, and then removes the protective layer to avoid interfering with the final device performance.
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 seal layer effectively prevents structural damage and short circuits, enhancing the performance and reliability of the semiconductor device by safeguarding the MRAM structure from etching and spacer layer shrinkage, thereby improving the overall device structure and functionality.
Implementation Method 1
a seal layer is additionally formed on the MRAM structure, to protect the MRAM structure disposed underneath. In this way, the seal layer may be used to avoid the exposure of the MRAM structure during the subsequent forming processes of the conductive patterns caused by excess etching, as well as the possible short circuit issue between the MTJ of the MRAM structure and the conductive pattern disposed thereon
Data Source
AI summary
A semiconductor device and method of forming the same, the semiconductor device includes a substrate, first plug, a magnetoresistive random access memory (MRAM) structure, a spacer layer, a seal layer and a first conductive pattern. The substrate has a first region and a second region, and the first plug is disposed on a dielectric layer disposed on the substrate, within the first region. The MRAM structure is disposed in the dielectric layer and electrically connected to the first plug. The spacer layer is disposed both within the first region and the second region, to cover the MRAM structure. The seal layer is disposed on the MRAM structure and the first plug, only within the first region. The first conductive pattern penetrates through the seal layer to electrically connect the MRAM structure.