Partitioned TSV Connection Pads for Semiconductor Yield
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Solution Overview
Problem
The via last system in TSV technique for semiconductor devices faces issues such as dishing in connection pads during CMP, leading to defective wiring and reduced manufacturing yield, as well as moisture and metal ion intrusion into interlayer insulating films, affecting the reliability and operation characteristics of semiconductor elements.
Innovation Solution
A method involving the formation of connection pads and through electrodes using a partitioned approach, where trenches are formed in a dual-damascene process to minimize dishing and prevent exposure of interlayer insulating films, ensuring the integrity of the through hole and reducing the risk of moisture and ion intrusion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If connection pads are formed by damascene method with large planar area, then electrical connection is achieved, but dishing is generated in CMP process leading to defective wiring and reduced manufacturing yield
Solution Approach 1:
The connection pad-forming region is divided into multiple partitioned regions, and connection pads are formed separately in each partitioned region. This segmentation approach reduces the planar area of individual connection pads, thereby minimizing dishing during CMP while maintaining adequate electrical connection capability through the distributed arrangement of multiple smaller pads
2Reliability
If through hole is formed to pass through silicon substrate and interlayer insulating film, then vertical connection is achieved, but interlayer insulating film is exposed in side surface allowing moisture and metal ion intrusion
Solution Approach 1:
The insulating film is selectively formed only on the side surface of the through hole, providing localized protection where it is most needed (at the interface with interlayer insulating film) without adding unnecessary complexity elsewhere. This targeted approach prevents moisture and ion intrusion while maintaining structural simplicity
Data Source
AI summary
To provide a technique adopting a TSV technique, capable of improving manufacturing yield and reliability of semiconductor devices. By partitioning a connection pad-forming region into a plurality of regions and by forming, respectively, connection pads 17 having a relatively small planar area, spaced apart from an adjacent connection pad 17 in each of partitioned regions, dishing generated in the connection pad 17 is lightened. In addition, by not forming a through hole 23 for forming a through electrode 27 in an interlayer insulating film 9 covering a semiconductor element, intrusion of H2O, a metal ion such as Na+ or K+, etc. into an element-forming region from the through hole, via the interlayer insulating film is prevented.