Multilevel Interconnect Reliability Test Structure

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Solution Overview

Problem

Conventional methods for testing the reliability of semiconductor devices require multiple test structures for each conducting layer, occupying valuable space on the chip and limiting the ability to efficiently predict and detect stress-induced electromigration in multi-level interconnect structures.

Innovation Solution

A single test structure with multiple segments of different metal layers and nodes configured to receive and sense forces and voltages, allowing for rapid and precise detection of stress-induced electromigration across multiple interconnect metallization layers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple separate test structures are used for each conducting layer, then the reliability testing coverage is improved, but the chip space occupied increases and device complexity increases

Engineering Contradiction:

Improvereliability testing coverageVSAvoidchip space

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The patent combines multiple separate test structures for different conducting layers into a single integrated test structure. The test structure includes segments from first and second conducting layers connected through via structures, allowing simultaneous testing of multiple layers. This merging reduces the total chip space required while maintaining comprehensive reliability testing coverage for electromigration in both conducting layers.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The single test structure serves multiple functions by incorporating segments from different conducting layers (first and second metal layers) and enabling testing of electromigration reliability across all layers. The structure includes force nodes and sense nodes that can detect stress-induced electromigration in both the first conducting layer segment and the second conducting layer segment, making it a universal test solution for multi-level interconnects.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If multiple separate test structures are used for each conducting layer, then the reliability testing coverage is improved, but the device complexity increases

Engineering Contradiction:

Improvereliability testing coverageVSAvoidtest structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges multiple separate test structures into one unified test structure that simultaneously tests electromigration reliability in both the first and second conducting layers. This consolidation reduces device complexity by eliminating redundant separate test structures while maintaining comprehensive reliability testing coverage through the integrated multi-layer design with shared via connections.

Inventive Principle:

Principle #5Merging (Combining)

3Measurement precision

If conventional testing methods are used, then individual layer testing is achieved, but the ability to efficiently predict and detect stress-induced electromigration in multi-level interconnect structures is limited

Engineering Contradiction:

Improveelectromigration detection precisionVSAvoidtesting efficiency

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The test structure is designed with universal applicability to detect stress-induced electromigration in multiple conducting layers simultaneously. It includes segments from both the first and second conducting layers with force nodes and sense nodes configured to measure electromigration effects in each layer, enabling efficient multi-layer testing that improves both detection precision and testing productivity compared to conventional single-layer methods.

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 approach enables efficient detection of electromigration in both upper and lower metal layers, reducing chip space usage and improving the ability to predict and locate failure points, thereby enhancing the reliability and yield of semiconductor devices.

Implementation Method 1

testing for breakdown in conductivity of an interconnect structure attributable to electromigration

Methodology Applied

Scientific EffectElectromigration:

Implementation Method 2

nodes configured to receive force and sense voltages. Selective application of force and sense voltages to these nodes allows rapid and precise detection of stress-induced immigration

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentUS8323990B2Reliability test structure for multilevel interconnect

Publication Date: 2012.12.04 SEMICON MFG INT (SHANGHAI) CORP

AI summary

Embodiments in accordance with the present invention relate to structures and methods allowing stress-induced electromigration to be tested in multiple interconnect metallization layers. An embodiment of a testing structure in accordance with the present invention comprises at least two segments of a different metal layer through via structures. Each segment includes nodes configured to receive force and sense voltages. Selective application of force and sense voltages to these nodes allows rapid and precise detection of stress-induced immigration in each of the metal layers.