TSV Guard Ring Structure for Blocking Water Migration
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Solution Overview
Problem
Current semiconductor chips face issues with water migration during through silicon via (TSV) formation, leading to oxidation of barrier layers and unwanted electrical paths due to the production of water during insulating material deposition, which weakens the BEOL wiring and can cause metal nodules to form, affecting the integrity and performance of the chip.
Innovation Solution
Incorporating a guard ring structure with specific surface spacings and configurations around the TSV to prevent water migration and protect the BEOL wiring, comprising multiple guard ring elements with distinct upper and lower sections, and using metallization techniques to ensure the integrity of the TSV and wiring layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If insulating material is deposited during TSV formation, then the TSV is isolated electrically, but water is produced as a byproduct which migrates and causes oxidation of barrier layers
Solution Approach 1:
A guard ring structure is introduced as an intermediary element between the TSV and the BEOL wiring. The guard ring includes a first portion and a second portion that create physical and chemical barriers to prevent water produced during insulating material deposition from migrating to and oxidizing the barrier layers of the BEOL wiring.
Solution Approach 2:
The guard ring is formed in advance before the insulating material deposition process. It is positioned and configured to preemptively block the path of water migration, thereby preventing oxidation of barrier layers before it can occur during the subsequent insulating material deposition.
2Adaptability or versatility
If TSV passes completely through the semiconductor substrate, then connectivity between stacked chips is achieved, but water can migrate through the entire path causing widespread oxidation
Solution Approach 1:
The guard ring acts as an intermediary barrier structure that interrupts the continuous path through the semiconductor substrate. By positioning the guard ring at strategic locations around the TSV, it creates discontinuities that block water migration while maintaining the electrical connectivity function of the TSV.
Solution Approach 2:
The guard ring is divided into multiple portions (first portion and second portion) that are positioned at different locations around the TSV. This segmentation creates multiple barrier points that collectively block water migration paths while allowing the TSV to maintain its through-substrate connectivity function.
3Object-affected harmful factors
If guard ring structure is added around TSV, then water migration is blocked, but device complexity increases
Solution Approach 1:
The guard ring is implemented using thin film structures that are deposited as part of the existing BEOL wiring process. These thin film guard ring structures provide effective water migration barriers while minimizing the additional volume and structural complexity added to the device.
Solution Approach 2:
The guard ring formation process is merged with the existing BEOL wiring fabrication process. The guard ring portions are formed using similar deposition and patterning steps as the wiring layers, thereby reducing process complexity and avoiding the need for entirely separate manufacturing steps.
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
The guard ring effectively blocks water migration, preventing oxidation of barrier layers and reducing the formation of unwanted electrical paths, thereby enhancing the reliability and performance of the semiconductor chip by maintaining the integrity of the BEOL wiring and TSV.
Implementation Method 1
the guard ring effectively blocks water migration, preventing oxidation of barrier layers
Implementation Method 2
the production of water during insulating material deposition
Implementation Method 3
water migration during through silicon via (TSV) formation, leading to oxidation of barrier layers
Implementation Method 4
preventing oxidation of barrier layers
Data Source
AI summary
A semiconductor article which includes a semiconductor substrate, a back end of the line (BEOL) wiring portion on the semiconductor substrate, a through silicon via and a guard ring. The semiconductor substrate is made of a semiconductor material. The BEOL wiring portion includes a plurality of wiring layers having electrically conductive wiring and electrical insulating material. The through silicon via provides a conductive path through the BEOL wiring portion and the semiconductor substrate. The guard ring surrounds the through silicon via in the BEOL wiring portion and in some embodiments in the semiconductor substrate.