3D E-Fuse Structure with Via Layer for Low Blowing Current

Solution Overview

Problem

Semiconductor components are susceptible to defects during complex processes, leading to issues in IC manufacturing yield and programming, as existing fuse circuits require high blowing currents for effective open circuit creation.

Innovation Solution

The e-fuse structure incorporates top and bottom conductive patterns with extension portions and a via conductive layer, amplifying the electro-migration effect to reduce the required blowing current and increase the blowing window, allowing for a larger operational range.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional fuse structures are used, then the open circuit condition can be achieved, but the blowing current required is high which limits the blowing window

Engineering Contradiction:

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The fuse structure is segmented into top and bottom conductive patterns with extension portions, and a via conductive layer connecting them. This segmentation creates multiple paths for electro-migration, amplifying the effect and reducing the required blowing current while maintaining reliable open circuit condition.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The fuse structure transitions from a planar configuration to a three-dimensional structure by adding vertical via conductive layers connecting top and bottom extension portions. This dimensional change increases the effective path length for electro-migration without increasing the lateral footprint, thereby reducing blowing current requirements.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Reliability

If high blowing current is used, then the open circuit condition is achieved, but the blowing window becomes small reducing operational flexibility

Engineering Contradiction:

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

By segmenting the fuse into top/bottom patterns with extension portions connected via vias, the structure creates multiple electro-migration pathways. This segmentation amplifies the cumulative electro-migration effect, enlarging the blowing window to approximately 2.5 times that of conventional fuses and improving operational flexibility.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The transition to a 3D structure with vertical via connections increases the effective electro-migration path length without increasing lateral dimensions. This dimensional enhancement expands the blowing window, providing a larger operational range for fuse blowing operations.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Ease of manufacture

If the fuse structure is simplified, then manufacturing is easier, but the blowing current reduction effect is lost

Engineering Contradiction:

Core Design Contradiction:

Ease of manufactureVSUse of energy by moving object

Solution Approach 1:

The top and bottom conductive patterns with their extension portions are formed using the same manufacturing process steps as existing metal interconnection structures. By merging the fuse structure creation with standard interconnection fabrication, the patent achieves blowing current reduction without adding manufacturing complexity.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The fuse structure utilizes the same materials and processes as the metal interconnection system, making it universally compatible with existing manufacturing workflows. This multi-functionality allows the fuse to benefit from established fabrication processes while achieving reduced blowing current through its enhanced 3D configuration.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 design reduces the blowing current needed for an open circuit condition, enhances the blowing window, and improves data security by making it more difficult to locate the blowing point in the via conductive layer, particularly beneficial for programming and memory elements.

Implementation Method 1

e-fuse having the open circuit condition provided by proper circuit generating electro-migration (EM) effect

Methodology Applied

Scientific EffectElectro-migration effect:

Data Source

PatentUS8922328B2Electrical fuse structure

Publication Date: 2014.12.30

AI summary

An electrical fuse structure includes a top conductive pattern having a top fuse and a top fuse extension portion, a bottom conductive pattern having a bottom fuse and a bottom fuse extension portion corresponding to the top fuse extension portion, and a via conductive layer positioned between the top fuse extension portion and the bottom fuse extension portion for electrically connecting the top fuse extension portion and the bottom fuse extension portion.