Semiconductor Fuse Structure with Dummy Elements for Defect Containment

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Solution Overview

Problem

Existing electrically programmable fuse (eFUSE) structures in semiconductor devices face issues such as high resistance excursions due to voids and cracks in the silicide film, leading to yield loss and reliability problems, as well as electrical shorts and migration of defects into adjacent structures.

Innovation Solution

Incorporating auxiliary dummy structures adjacent to the fuse body, flared portions at the ends of the fuse body, and a doped well region to reduce stress and contain defects, along with a dielectric structure to isolate and confine cracks, enhancing material migration and transfer during programming.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If electromigration effects are used to change resistance in polysilicon/silicide fuse structures, then flexible programming is achieved, but high resistance excursions occur due to voids and cracks in the silicide film

Engineering Contradiction:

Improveprogramming flexibilityVSAvoidresistance stability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

A dummy fuse structure is introduced as an intermediary element adjacent to the functional fuse body. This dummy structure absorbs stress and prevents crack formation in the silicide film during electromigration programming, thereby maintaining resistance stability while preserving programming flexibility

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The dummy fuse structure is positioned in advance to cushion and absorb thermal and mechanical stress before cracks can form in the functional fuse. This preemptive stress absorption prevents voids and cracks during the electromigration process, ensuring reliable resistance changes without high resistance excursions

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Ease of operation

If voltage or current controlled bias is applied across the polysilicon/silicide fuse for programming, then eFUSE functionality is achieved, but electrical shorts and defect migration into adjacent structures occur

Engineering Contradiction:

Improveprogramming capabilityVSAvoidelectrical shorts and defect migration

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The dummy fuse structure acts as a buffer zone between the high-stress functional fuse and adjacent circuit structures. During voltage-controlled programming, it captures migrating defects and prevents them from reaching sensitive adjacent areas, thereby eliminating electrical shorts while maintaining programming capability

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The dummy fuse structure converts the harmful effect of material migration during programming into a beneficial containment mechanism. Migrating silicide material and dopants are redirected into the dummy structure instead of causing shorts in adjacent circuits, transforming a potential failure mode into a protective feature

Inventive Principle:

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

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

This approach significantly reduces the occurrence of high resistance excursions and defects, improving yield and reliability by containing cracks and voids, and preventing electrical shorts, resulting in more accurate programming and reduced material migration.

Implementation Method 1

The silicide material and dopants within the polysilicon migrate or move by electron current and a thermal gradient from one region of the fuse structure to another

Methodology Applied

Scientific EffectElectromigration:

Implementation Method 2

The silicide material and dopants within the polysilicon migrate or move by electron current and a thermal gradient from one region of the fuse structure to another

Methodology Applied

Scientific EffectThermal gradient: Temperature Gradient

Data Source

PatentUS11355433B2Semiconductor fuse structure and method of manufacturing a semiconductor fuse structure

Publication Date: 2022.06.07 SEMICON COMPONENTS IND LLC

AI summary

A semiconductor device having a fuse structure includes a region of semiconductor material having a major surface. A dielectric region is over the major surface. A first fuse terminal is over a first part of the dielectric region, a second fuse terminal is over a second part of the dielectric region and spaced apart from the first fuse terminal to provide a gap region, and a fuse body over a third part of the dielectric region interposed between and connected to the first fuse terminal and the second fuse terminal. A dummy structure is over the dielectric region in the gap region on a first side of the fuse body, the dummy structure spaced apart and electrically isolated from the fuse body, the first fuse terminal, and the second fuse terminal. The dummy structure is configured to reduce the presence of or reduce the effects of defects, such as cracks or voids that can emanate from the fuse structure.