Reinforced IC Seal Ring Layout for Singulation Stress Protection

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Solution Overview

Problem

Multi-gate semiconductor devices, such as FinFETs and MBC transistors, are prone to damage from mist ingress and stress during the singulation process due to inadequate mechanical strength and stress absorption in existing seal structures, particularly in metal lines with dimensions smaller than 1 μm.

Innovation Solution

The integration of a seal ring structure with metal line loops and lateral connectors in the interconnect structure, where the metal line loops completely encircle the device portion and are laterally connected by connectors perpendicular to their longitudinal direction, enhancing mechanical integrity and stress absorption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of moving object

If metal line dimensions are reduced to smaller than 1 μm to enable scaling, then device density and integration are improved, but mechanical strength and stress absorption of seal structures deteriorate

Engineering Contradiction:

Improvedevice densityVSAvoidmechanical strength of seal structures

Core Design Contradiction:

Area of moving objectVSStrength

Solution Approach 1:

The seal ring structure is segmented into multiple components: a first seal ring, a second seal ring, and multiple tie bars connecting them. This segmentation allows each component to be optimized independently while collectively providing enhanced mechanical strength despite reduced metal line dimensions

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The seal structure uses composite construction with multiple metal line loops and connecting tie bars forming a reinforced composite structure. This composite design provides superior mechanical strength and stress absorption compared to single-loop seal structures of the same scale

Inventive Principle:

Principle #40Composite materials

2Ease of manufacture

If existing seal structures are used without reinforcement, then manufacturing simplicity is maintained, but protection against mist ingress and stress during singulation is insufficient

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidprotection against mist ingress and stress

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The reinforced seal ring structure is formed as part of the interconnect structure before singulation. The multiple metal line loops and tie bars are preliminarily constructed to provide stress absorption and protection against mist ingress during the subsequent singulation process

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The tie bars and multiple seal rings provide beforehand cushioning by absorbing stress and preventing mist ingress during singulation. This protective function is built into the structure in advance to cushion against harmful effects during manufacturing

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentUS20240379587A1Seal ring reinforcement

Publication Date: 2024.11.14 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

Integrated circuit (IC) chips and seal ring structures are provided. An IC chip according to the present disclosure includes an interconnect structure that includes a first metal line, a second metal line, a third metal line, a fourth metal line, and a fifth meal line extending along a first direction, a first group of lateral connectors disposed between the second metal line and the third metal line or between the fourth metal line and the fifth metal line, and a second group of lateral connectors disposed between the first metal line and the second metal line or between the third metal line and the fourth metal line.