Double-Sided Fabrication of Low-Leakage-Current Through-Silicon Vias (TSVs) with High-Step-Coverage Liner/Barrier Layers

In this paper, a novel through-silicon via (TSV) fabrication strategy based on through-hole structures is proposed for low-cost and low-complexity manufacturing. Compared to conventional TSV fabrication processes, this method significantly simplifies the process flow by employing double-sided liner...

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Bibliographic Details
Main Authors: Baoyan Yang, Houjun Sun, Kaiqiang Zhu, Xinghua Wang
Format: Article
Language:English
Published: MDPI AG 2025-06-01
Series:Micromachines
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Online Access:https://www.mdpi.com/2072-666X/16/7/750
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Summary:In this paper, a novel through-silicon via (TSV) fabrication strategy based on through-hole structures is proposed for low-cost and low-complexity manufacturing. Compared to conventional TSV fabrication processes, this method significantly simplifies the process flow by employing double-sided liner deposition, double-sided barrier layer/seed layer formation, and double-sided Cu electroplating. This method enhances the TSV stability by eliminating Cu contamination issues during chemical–mechanical polishing (CMP), which are a common challenge in traditional blind via fabrication processes. Additionally, the liner and barrier layer/seed layer achieve a high step coverage exceeding 80%, ensuring excellent conformality and structural integrity. For electroplating, a multi-stage bi-directional electroplating technique is introduced to enable void-free Cu filling in TSVs. The fabricated TSVs exhibit an ultra-low leakage current of 135 fA at 20 V, demonstrating their potential for advancing 3D integration technologies in heterogeneous integration.
ISSN:2072-666X