TSV Conductive Protective Layers for Diffusion Control
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Solution Overview
Problem
Current Through-Silicon-Via (TSV) structures face challenges in achieving reliable three-dimensional integration due to limitations in conductive via formation and interconnectivity between stacked substrates, particularly in terms of material diffusivity and structural integrity.
Innovation Solution
The implementation of a conductive via structure with a Ni and/or Co conductive protective layer and a separate polymer insulating layer, along with a diffusion barrier layer, to enhance the integrity and connectivity of TSVs, allowing for effective signal transmission between substrates while minimizing material diffusivity into the silicon substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional TSV structure without separate polymer insulating layer is used, then the manufacturing process is simpler, but material diffusivity into the silicon substrate increases and structural integrity deteriorates
Solution Approach 1:
The patent divides the insulating structure into two separate layers: a polymer insulating layer deposited conformally on the via wall and a separate planarizing insulating layer deposited over the entire surface. This segmentation allows each layer to perform its specific function optimally - the polymer layer provides diffusion barrier and adhesion, while the separate planarizing layer provides mechanical support and planarity without compromising the underlying protective structure.
Solution Approach 2:
The patent employs composite material structure by combining different insulating materials (polymer and oxide/nitride) with distinct properties. The polymer insulating layer offers excellent adhesion to metal and silicon, while the separate planarizing insulating layer provides mechanical strength and planarity. This composite approach resolves the contradiction by leveraging the strengths of each material for specific functions.
2Object-generated harmful factors
If diffusion barrier layer is added to prevent material diffusivity, then material diffusivity into substrate is reduced, but the manufacturing process complexity increases
Solution Approach 1:
The patent introduces a polymer insulating layer as an intermediary between the conductive via and the silicon substrate. This intermediate layer serves as an effective diffusion barrier that prevents metal atoms from migrating into the silicon substrate. The polymer material acts as a mediator that blocks diffusion pathways while being compatible with standard semiconductor fabrication processes.
Solution Approach 2:
The patent changes the material parameter of the insulating layer from conventional oxide/nitride to polymer material. This parameter change provides superior diffusion barrier properties due to the polymer's molecular structure that effectively blocks metal atom migration. The polymer's chemical composition and physical properties are optimized to prevent material diffusivity while maintaining process compatibility.
3Reliability
If conductive protective layer with Ni and/or Co is implemented, then electrical connectivity and structural stability are improved, but manufacturing complexity increases
Solution Approach 1:
The patent applies local quality by implementing a conductive protective layer specifically at the bottom of the via hole where it is most needed for adhesion and electrical connectivity. The Ni and/or Co layer is deposited only in the via region rather than uniformly across the entire substrate, providing enhanced electrical connectivity and structural stability at the critical interface while minimizing overall manufacturing complexity and material usage.
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 solution enables robust and efficient three-dimensional integration by ensuring reliable electrical connectivity and structural stability, facilitating the formation of stacked structures with improved performance and reliability.
Implementation Method 1
a conductive protective layer comprising Ni and/or Co at a bottom of the conductive via
Implementation Method 2
a separate polymer insulating layer on the backside surface of the substrate in contact with the conductive protective layer
Implementation Method 3
a conductive via through a substrate extending from an upper surface of the substrate to a backside surface of the substrate
Data Source
AI summary
Through-Silicon-Via (TSV) structures can include a conductive via through a substrate extending from an upper surface of the substrate to a backside surface of the substrate opposite the upper surface, a conductive protective layer including Ni and/or Co can be at a bottom of the conductive via, and a separate polymer insulating layer can be on the backside surface of the substrate in contact with the conductive protective layer.