Through-Via Guard Ring Layout for Stress and Defect Control

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Solution Overview

Problem

Existing IC packaging technologies face challenges in protecting and enhancing the reliability and integrity of through vias (TSVs) due to defects arising from suboptimal spacing and overlap between guard rings and TSVs, which can lead to stress concentration and performance degradation.

Innovation Solution

A guard ring design is proposed that optimizes the spacing and overlap between the guard ring and TSV, with a specific ratio of guard ring diameter to TSV diameter and controlled overlap between metal layers to reduce defects during TSV fabrication.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If guard ring spacing and overlap are not optimized, then manufacturing process is simpler, but defects increase and TSV reliability deteriorates

Engineering Contradiction:

ImproveTSV reliabilityVSAvoidguard ring spacing and overlap control

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by optimizing the spacing between guard rings and TSVs, controlling the overlap between metal layers, and establishing specific ratios of guard ring diameter to TSV diameter. These parameter optimizations reduce defects during TSV fabrication while maintaining manufacturing feasibility, directly resolving the contradiction between TSV reliability and manufacturing precision control.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If guard ring diameter is increased to improve TSV protection, then TSV reliability improves, but device area increases

Engineering Contradiction:

ImproveTSV integrityVSAvoidguard ring area

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The patent optimizes the guard ring diameter to TSV diameter ratio, establishing a specific parameter relationship that provides adequate TSV protection while minimizing the area occupied by guard rings. This parameter optimization resolves the contradiction between TSV integrity and device area by finding the optimal balance point.

Inventive Principle:

Principle #35Parameter changes

3Stability of the object's composition

If metal layer overlap is increased to improve stress distribution, then structural stability improves, but manufacturing precision requirements increase

Engineering Contradiction:

Improvestructural stabilityVSAvoidmetal layer overlap control

Core Design Contradiction:

Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The patent controls the overlap between metal layers within specific parameter ranges that provide adequate stress distribution and structural stability while remaining achievable with standard manufacturing tolerances. This resolves the contradiction by identifying optimal overlap parameters that balance structural requirements with manufacturing capabilities.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS20250351471A1Guard Ring Design For Through Via

Publication Date: 2025.11.13 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

An exemplary semiconductor structure includes a device substrate having a first side and a second side. A dielectric layer is disposed over the first side of the device substrate. A through via extends along a first direction through the dielectric layer and through the device substrate from the first side to the second side. A guard ring is disposed in the dielectric layer and around the through via. The guard ring includes metal layers stacked along the first direction. The metal layers include first sidewalls and second sidewall. The first sidewalls form an inner sidewall of the guard ring. An overlap between the first sidewalls of the metal layers is less than about 10 nm. The overlap is along a second direction different than the first direction.