Cu Electrode Insulating Film Structure to Prevent Edge Cracking

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Solution Overview

Problem

In semiconductor devices with a Cu electrode layer on an insulating layer with a barrier electrode layer in between, cracks often occur near the peripheral edge of the barrier electrode layer due to thermal expansion stresses applied through an outer-surface insulating film containing copper oxide.

Innovation Solution

The semiconductor device is designed with an outer-surface insulating film that coats the Cu electrode layer and is in contact with the barrier electrode layer, but is formed to avoid direct contact with the insulating layer, thereby reducing thermal expansion-induced stresses. Additionally, a resin film is used to coat the Cu electrode layer, preventing copper oxide formation and further reducing stress on the insulating layer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an outer-surface insulating film containing copper oxide is formed on the Cu electrode layer, then the insulating property is improved, but thermal expansion stresses cause cracks near the barrier electrode layer

Engineering Contradiction:

Improveinsulating propertyVSAvoidcrack resistance

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

A resin film is introduced as an intermediary layer between the Cu electrode layer and the outer-surface insulating film. This resin film prevents direct contact between the copper oxide-containing insulating film and the Cu electrode layer, thereby blocking the transmission path of thermal expansion stresses that would otherwise cause cracks in the barrier electrode layer, while still allowing the insulating film to provide its insulating function.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The resin film is applied beforehand to the Cu electrode layer to create a protective cushioning layer. This layer absorbs and mitigates the thermal expansion stresses before they can reach the barrier electrode layer and cause cracks, preventing the harmful effect from occurring in the first place.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Reliability

If the outer-surface insulating film is in contact with the barrier electrode layer, then the insulating property is improved, but thermal expansion stresses are transmitted to the insulating layer causing cracks

Engineering Contradiction:

Improveinsulating propertyVSAvoidthermal expansion stress

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The resin film serves as a mediator that allows the outer-surface insulating film to maintain its insulating function while preventing the transmission of thermal expansion stresses to the barrier electrode layer and insulating layer, thus blocking the harmful effect pathway.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If copper oxide is present in the outer-surface insulating film, then insulation performance is enhanced, but stress concentration occurs at the interface with the barrier electrode layer

Engineering Contradiction:

Improveinsulation performanceVSAvoidstress concentration

Core Design Contradiction:

ReliabilityVSStress or pressure

Solution Approach 1:

The resin film acts as an intermediary that decouples the stress transmission between the copper oxide-containing insulating film and the barrier electrode layer. This allows the insulating film to maintain its high insulation performance while the resin film absorbs the stress concentration that would otherwise occur at the interface.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 effectively prevents cracks in the insulating layer by minimizing the thermal expansion-induced stresses applied to the barrier electrode layer and the insulating layer, thereby enhancing the reliability and durability of the semiconductor device.

Implementation Method 1

cracks often occur near the peripheral edge of the barrier electrode layer due to thermal expansion stresses applied through an outer-surface insulating film containing copper oxide

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

a resin film is used to coat the Cu electrode layer, preventing copper oxide formation and further reducing stress on the insulating layer

Methodology Applied

Scientific EffectOxidation: Oxidation

Data Source

PatentUS20250079369A1Semiconductor device

Publication Date: 2025.03.06 ROHM CO LTD

AI summary

A semiconductor device includes an insulating layer, a barrier electrode layer formed on the insulating layer, a Cu electrode layer that includes a metal composed mainly of copper and that is formed on a principal surface of the barrier electrode layer, and an outer-surface insulating film that includes copper oxide, that coats an outer surface of the Cu electrode layer, and that is in contact with the principal surface of the barrier electrode layer.