Crack Deflecting Scribe Seal for Semiconductor Saw Damage

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Solution Overview

Problem

Integrated circuits face mechanical defects and crack propagation issues during separation processes due to scribe lines, which conventional scribe seals do not adequately address, especially in low-k dielectric materials under tensile stress.

Innovation Solution

A crack deflecting scribe seal is introduced, featuring continuous metal layers and contacts with recessed vias, forming an angled outer surface that deflects or terminates crack propagation upward, preventing damage from scribeline cracks and providing additional mechanical strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional scribe seals are used to separate ICs, then separation is achieved, but crack propagation into ICs cannot be effectively prevented

Engineering Contradiction:

Improvecrack propagation resistanceVSAvoidscribe seal structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The scribe seal structure is segmented into multiple functional layers: continuous metal layers, continuous contacts, continuous vias, and an angled outer surface. Each segment serves a specific function in crack deflection, creating a multi-layered defense system that progressively redirects cracks away from the IC interior.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention introduces a new geometric dimension by creating an angled outer surface that slopes upward from the scribeline toward the IC interior. This angular geometry adds a dimensional element that conventional flat scribe seals lack, enabling cracks to be deflected upward along the angled surface rather than propagating straight into the IC.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Reliability

If scribe seals provide resistance to crack propagation, then some protection is achieved, but complete crack termination is not realized

Engineering Contradiction:

Improvecrack propagation resistanceVSAvoidmechanical strength

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The scribe seal employs a composite structure combining multiple materials and geometries: continuous metal layers provide structural backbone, continuous contacts and vias create vertical interconnect pathways, and the angled outer surface formed by recessed vias creates a geometric barrier. This composite approach leverages the strengths of each component to achieve superior crack resistance.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The invention converts the potentially harmful concentrated stress at the scribe seal interface into a beneficial distributed stress pattern. The angled outer surface and recessed vias redistribute crack propagation forces along the angled geometry, transforming the concentrated harmful stress into distributed beneficial stress that redirects cracks away from the IC interior.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Data Source

PatentUS10109597B2Crack deflector structure for improving semiconductor device robustness against saw-induced damage

Publication Date: 2018.10.23 TEXAS INSTRUMENTS INC

AI summary

An integrated circuit containing a crack deflecting scribe seal which separates an interior region of the integrated circuit from a scribeline immediately outside the integrated circuit and a method of forming the same. The crack deflecting scribe seal includes continuous metal layers and continuous contacts and continuous vias between the continuous metal layers. The continuous metal layers do not extend past the continuous contacts and continuous vias. The continuous contacts and continuous vias are recessed from edges of the underlying continuous metal layers on the scribeline side of the scribe seal, providing an angled outer surface on the scribe seal which may desirably terminate crack propagation or deflect crack propagation upward to a top surface of the scribeline or the crack deflecting scribe seal.