Through Via Structure with Selective CVD Barrier
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Solution Overview
Problem
In high-density package applications, the miniaturization of through via structures leads to increased aspect ratios, resulting in voids or seams during conductive layer filling and corrosion issues due to galvanic effects in existing interconnection technologies.
Innovation Solution
A method involving the formation of a conductive via by stacking a conductive barrier layer and a conductive layer using selective Chemical Vapor Deposition (CVD), which eliminates the need for additional adhesion layers and improves gap filling, thereby avoiding voids and corrosion, and reduces Chemical Mechanical Polishing (CMP) loading.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the dimension of through via structure is reduced to micron or sub-micron level for high-density package application, then the density of package is improved, but the aspect ratio of through via structure is increased causing void or seam during conductive layer filling
Solution Approach 1:
The conductive via is divided into multiple layers: a conductive barrier layer (first conductive layer) and a conductive layer (second conductive layer). This segmentation allows each layer to perform its specific function - the barrier layer prevents corrosion and the conductive layer provides electrical connection, thereby solving the filling quality issue while maintaining high density
Solution Approach 2:
The patent changes the deposition parameters by using selective Chemical Vapor Deposition (CVD) method with controlled deposition conditions. This allows precise control over the conductive layer formation in high-aspect-ratio via holes, eliminating voids and seams while achieving the required fill quality for micron and sub-micron dimensions
2Productivity
If the aspect ratio of through via structure is increased due to miniaturization, then the package density is improved, but void or seam occurs during conductive layer filling
Solution Approach 1:
The conductive via is segmented into a conductive barrier layer and a conductive layer, where each layer is deposited with optimized parameters suitable for high-aspect-ratio structures. This segmentation ensures reliable filling without voids or seams in micron and sub-micron dimensions
Solution Approach 2:
The patent replaces traditional electroplating or physical vapor deposition methods with selective Chemical Vapor Deposition (CVD). This substitution provides better gap-filling capability and conformal coverage in high-aspect-ratio via holes, ensuring complete and defect-free filling
3Ease of manufacture
If conventional interconnection technology is used in high-density package, then the manufacturing process is simple, but corrosion issue due to galvanic effect occurs
Solution Approach 1:
The conductive via is segmented into a conductive barrier layer and a conductive layer. The barrier layer specifically addresses corrosion resistance while the conductive layer maintains electrical connectivity. This segmentation eliminates galvanic corrosion issues while remaining compatible with existing manufacturing processes
Solution Approach 2:
The conductive via uses a composite structure combining a conductive barrier material and a conductive material. This composite approach provides both corrosion resistance and electrical conductivity, solving the galvanic corrosion problem inherent in conventional single-material interconnection technology
4Strength
If additional adhesion layers are used in conventional through via structure, then the adhesion strength is improved, but the device complexity and CMP loading are increased
Solution Approach 1:
The conductive barrier layer serves multiple functions simultaneously: it provides adhesion between the conductive via and surrounding structures, prevents corrosion, and enables electrical conductivity. This multi-functionality eliminates the need for separate adhesion layers, reducing structural complexity and CMP loading
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 effectively prevents voids and seams in high-aspect-ratio via holes and avoids galvanic corrosion, while minimizing the risk of damaging surrounding structures during CMP, enhancing the reliability of semiconductor interconnections.
Implementation Method 1
forming a conductive via by stacking a conductive barrier layer and a conductive layer using selective Chemical Vapor Deposition (CVD)
Data Source
AI summary
A through via structure includes a conductive wiring, at least one dielectric layer over the conductive wiring, a via hole in the at least one dielectric layer and exposing the conductive wiring, and a conductive via in the via hole. The conductive via includes a conductive barrier layer in a bottom portion of the via hole, and a conductive layer in a top portion of the via hole.