Seed Layer Deposition on High-Aspect Ratio Vias
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Solution Overview
Problem
Forming a uniform and sufficient seed layer on high-aspect ratio vias in semiconductor devices is challenging due to the high aspect ratio, which affects plating adhesion and filling-plating efficiency, and existing methods struggle to reduce stress in the seed layer.
Innovation Solution
A method involving tilting the substrate to a predetermined angle, controlling pressure in multiple steps, and using a combination of Mo and Cu seed layers to ensure uniform deposition and enhanced adhesion, with the substrate being tilted front and back and left and right to achieve efficient Cu filling-plating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a seed layer is formed on high-aspect ratio vias using conventional deposition methods, then the deposition process can be completed, but the seed layer thickness becomes non-uniform and insufficient on the inner wall and bottom of vias
Solution Approach 1:
The substrate is dynamically tilted and rotated during the deposition process rather than remaining stationary. This dynamic movement ensures that the seed layer forming material is deposited at a predetermined angle or less, achieving uniform and sufficient thickness on both the inner wall and bottom of high-aspect ratio vias while maintaining process feasibility
Solution Approach 2:
The deposition process introduces substrate tilting and rotation movements, transforming the static deposition geometry into a dynamic multi-dimensional process. This allows the seed layer forming material to reach all surfaces of the high-aspect ratio vias effectively, solving the uniformity problem without excessive process complexity
2Productivity
If the aspect ratio of vias is increased to enhance integration, then more components can be packed, but plating adhesion and filling-plating efficiency deteriorate
Solution Approach 1:
A seed layer is formed as a preliminary step before Cu filling-plating. The seed layer is deposited with uniform and sufficient thickness on the inner wall and bottom of high-aspect ratio vias through substrate tilting and rotation, creating a reliable foundation that enables subsequent Cu filling-plating to proceed efficiently even in high-aspect ratio structures
Solution Approach 2:
The deposition parameters are optimized by controlling the substrate tilting angle and rotation speed to maintain a predetermined angle or less between the seed layer forming material direction and the via axis. This parameter control ensures uniform seed layer formation that enhances plating adhesion while accommodating high integration density requirements
3Reliability
If a thick seed layer is formed to ensure sufficient coverage, then plating adhesion improves, but stress in the seed layer increases
Solution Approach 1:
The deposition parameters including substrate tilting angle, rotation speed, and material flux are optimized to achieve the minimum sufficient thickness uniformly distributed on the via surfaces. This controlled parameter approach ensures adequate plating adhesion while minimizing excess material deposition that would generate harmful stress in the seed layer
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 allows for efficient Cu filling-plating with improved plating adhesion and reduced stress in the seed layer, enhancing the durability of metal wiring in electronic components.
Implementation Method 1
forming the seed layer is performed by at least one of a tilting movement for tilting the substrate front and back and left and right and a turning movement of the substrate so that a seed layer forming material is deposited at a predetermined angle or less
Data Source
AI summary
Disclosed are a method of forming a seed layer on a high-aspect ratio via and a semiconductor device having a high-aspect ratio via formed thereby. Thus, efficient Cu filling-plating is possible, and plating adhesion of the seed layer to filling-plated Cu can be simply and profitably enhanced, thus imparting high durability upon forming metal wiring for electronic components. Moreover, stress of the seed layer can be lowered, thereby enhancing plating adhesion.