MIM Capacitor Passivation Structure for Stress Crack Suppression

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Solution Overview

Problem

Existing methods fail to adequately address stress-induced damage and crack propagation in metal-insulator-metal (MIM) capacitors during semiconductor manufacturing, particularly due to surrounding layers and features like passivation layers and contact pads, leading to degraded performance.

Innovation Solution

Incorporating a stress-reduction feature within the passivation layer, comprising a multi-layer structure with an oxygen-containing layer sandwiched between nitrogen-containing layers, which acts as a crack stop and releases stress, preventing damage to MIM capacitors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If passivation layers and contact pads are formed over MIM capacitors, then device functionality and interconnections are achieved, but stress is induced on the MIM capacitors causing damage and crack propagation

Engineering Contradiction:

Improvedevice functionalityVSAvoidMIM capacitor integrity

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

A stress reduction feature is introduced as an intermediary element between the passivation layer and the MIM capacitor. This feature acts as a mediator that absorbs and redistributes stress, preventing direct transmission of harmful mechanical stress to the capacitor structure while maintaining the functional integrity of the passivation layer and contact pads.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The stress reduction feature is positioned and configured in advance to cushion against stress-induced damage before it can affect the MIM capacitor. By pre-positioning this protective element, the design anticipates and mitigates potential crack propagation and stress concentration issues that would otherwise compromise capacitor reliability during subsequent manufacturing steps.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Adaptability or versatility

If surrounding layers and features are added to MIM capacitors, then device complexity and functionality increase, but crack propagation to MIM capacitors increases

Engineering Contradiction:

Improvedevice functionalityVSAvoidcrack propagation

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The stress reduction feature serves as a protective intermediary between the surrounding layers (passivation layer and contact pads) and the MIM capacitor. It intercepts and mitigates crack propagation paths that would otherwise travel from the surrounding structures into the capacitor, allowing device complexity and functionality to increase without proportionally increasing damage risk.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If stress reduction feature is added to passivation layer, then MIM capacitor reliability improves, but device complexity increases

Engineering Contradiction:

ImproveMIM capacitor performanceVSAvoidpassivation layer structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The stress reduction feature is implemented as a segmented or patterned structure within the passivation layer rather than a continuous complex addition. This segmentation approach provides effective stress reduction functionality while maintaining manufacturing feasibility and limiting the increase in overall device complexity. The feature can be implemented as discrete elements or patterns that are integrated into existing manufacturing flows.

Inventive Principle:

Principle #1Segmentation

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

The stress-reduction feature effectively prevents stress-induced cracks and defects in MIM capacitors, enhancing their performance and reliability by maintaining structural integrity.

Implementation Method 1

a stress-reduction feature is embedded within the passivation layer... which acts as a crack stop and releases stress, preventing damage to MIM capacitors

Methodology Applied

Scientific EffectStress relaxation: Stress Relaxation

Data Source

PatentUS20250318158A1Method of forming a stress reduction structure for metal-insulator-metal capacitors

Publication Date: 2025.10.09 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

A method and semiconductor device including a substrate having one or more semiconductor devices. In some embodiments, the device further includes a first passivation layer disposed over the one or more semiconductor devices. The device may further include a metal-insulator-metal (MIM) capacitor structure formed over the first passivation layer. In addition, the device may further include a second passivation layer disposed over the MIM capacitor structure. In various examples, a stress-reduction feature is embedded within the second passivation layer. In some embodiments, the stress-reduction feature includes a first nitrogen-containing layer, an oxygen-containing layer disposed over the first nitrogen-containing layer, and a second nitrogen-containing layer disposed over the oxygen containing layer.