TSV and Metal Pad Integration via Single Conductive Fill
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Solution Overview
Problem
Conventional through-substrate via (TSV) formation processes face challenges in achieving precise etching and planarization, leading to inefficiencies and excess material removal, which affect the reliability and cost-effectiveness of 3D integrated circuits.
Innovation Solution
A novel TSV formation method involving etching through dielectric layers and substrates, with a continuous diffusion barrier layer extending from the top surface to the bottom, allowing for the same material to form both metal pads and TSVs without intermediate barriers, and using CMP to remove excess metallic material, optimizing the integration of metal pads and TSVs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional etching and planarization processes are used for TSV formation, then TSV openings can be formed and filled with conductive material, but the process requires multiple separate steps including intermediate barriers and planarization, leading to excess material removal and reduced manufacturing precision
Solution Approach 1:
The patent merges the TSV formation process with the metal pad formation process into a single integrated flow. The same conductive material filling step creates both the TSVs and the metal pads simultaneously, eliminating the need for separate planarization and intermediate barrier layers between TSVs and metal pads. This integration reduces process complexity and improves manufacturing precision by minimizing the number of process steps and material removal operations.
Solution Approach 2:
The conductive material filling step serves multiple functions simultaneously: it forms the TSVs, creates the metal pads, and establishes electrical connections between them. The etching process also serves dual purposes by creating both TSV openings and metal pad openings in the same operation. This multi-functionality reduces the overall process complexity and eliminates unnecessary intermediate steps.
2Reliability
If multiple intermediate barriers and planarization steps are used in TSV formation, then electrical coupling can be achieved, but material waste increases and cost-effectiveness decreases
Solution Approach 1:
The patent combines the TSV and metal pad formation into a single integrated process, eliminating the need for separate planarization steps and intermediate barrier materials. The conductive material is deposited in a way that simultaneously fills TSV openings and forms metal pads, removing the need for excess material removal and reducing material waste while maintaining electrical coupling reliability.
Solution Approach 2:
The patent extracts and eliminates unnecessary intermediate barrier layers and planarization steps from the conventional TSV formation process. By removing these redundant components, the process achieves electrical coupling between TSVs and metal pads with minimal material usage, reducing both material waste and manufacturing complexity.
3Ease of manufacture
If separate processes are used for TSV and metal pad formation, then each feature can be optimized independently, but the overall manufacturing cost increases and process efficiency decreases
Solution Approach 1:
The patent merges TSV formation and metal pad formation into a single integrated process flow. The same etching and conductive material filling steps create both features simultaneously, eliminating the need for separate manufacturing processes. This integration improves productivity by reducing the total number of process steps and enhances cost-effectiveness by minimizing material waste and process complexity.
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 enhances the precision and efficiency of TSV formation, reducing material waste and improving the electrical coupling of metal pads and TSVs, thereby enhancing the reliability and cost-effectiveness of 3D integrated circuits.
Implementation Method 1
using CMP to remove excess metallic material
Data Source
AI summary
A device includes a substrate having a first surface, and a second surface opposite the first surface. A through-substrate via (TSV) extends from the first surface to the second surface of the substrate. A dielectric layer is disposed over the substrate. A metal pad is disposed in the dielectric layer and physically contacting the TSV, wherein the metal pad and the TSV are formed of a same material, and wherein no layer formed of a material different from the same material is between and spacing the TSV and the metal pad apart from each other.