TSV Formation Using Mandrel-Based Segmentation
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Solution Overview
Problem
The conventional process of forming through-silicon-vias (TSVs) in semiconductor structures faces challenges due to the widening of TSV openings with technology node evolution, leading to damage to contact plugs and ILD layers during chemical mechanical polish (CMP) processes, which affects the integrity and functionality of the semiconductor structure.
Innovation Solution
A method is developed to form a TSV structure by patterning an opening in a substrate, depositing a dielectric layer and conductive material, and using CMP to remove excess material, ensuring the TSV structure extends continuously through the substrate while maintaining the integrity of the ILD and contact plugs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If TSV openings are widened to accommodate technology node evolution, then TSV conductivity and current carrying capacity are improved, but contact plugs and ILD layers are damaged during CMP processes
Solution Approach 1:
The patent segments the TSV structure by introducing a mandrel-based formation process that divides the TSV creation into distinct stages: mandrel deposition, spacer formation, and selective removal. This segmentation allows precise control over TSV dimensions and positioning, enabling wider openings without compromising surrounding structures during CMP processes.
Solution Approach 2:
The patent applies preliminary action by forming a sacrificial mandrel structure before creating the TSV opening. This mandrel serves as a template that pre-defines the TSV geometry and location, allowing subsequent spacer deposition and material filling to proceed with high precision. The preliminary mandrel structure protects contact plugs and ILD layers from damage during the CMP process by establishing clear boundaries for material removal.
2Ease of manufacture
If conventional TSV formation processes are used, then manufacturing simplicity is maintained, but structural integrity of semiconductor components is compromised
Solution Approach 1:
The patent introduces a sacrificial mandrel as an intermediary element that facilitates precise TSV formation. The mandrel acts as a temporary structure that guides spacer deposition and defines TSV geometry before being removed. This intermediary approach maintains manufacturing simplicity while achieving high structural integrity, as the mandrel can be formed using standard deposition techniques and removed through selective etching or CMP processes.
Solution Approach 2:
The patent utilizes parameter changes by controlling the deposition thickness of spacers around the mandrel, the composition of sacrificial material, and the etching selectivity ratios. These parameter adjustments enable precise control over TSV opening size, depth, and positioning without compromising surrounding structures. The method transforms the formation process from a direct etch approach to a controlled deposition-and-removal sequence, improving both precision and structural integrity.
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 the formation of reliable TSV structures that maintain the structural integrity of the semiconductor, enabling efficient electrical connections and enhancing the performance of 3D ICs by preventing damage to the ILD and contact plugs during the CMP process.
Implementation Method 1
portions of the oxide liner and the TSV metallic material is then subjected to a chemical mechanical polish (CMP) process
Data Source
AI summary
A semiconductor structure includes a dielectric layer disposed over a substrate. A metallic line is disposed in the dielectric layer. A through-silicon-via (TSV) structure continuously extends through the dielectric layer and the substrate. A surface of the metallic line is substantially leveled with a surface of the TSV structure.