Inter-Block Dielectric Structure for Corrosion-Resistant Recessed Contacts

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Solution Overview

Problem

In the manufacturing of integrated circuits, the formation of contact plugs for transistors faces challenges such as galvanic corrosion between different metal conductive structures, which can lead to increased resistivity and reliability issues.

Innovation Solution

The introduction of an inter block dielectric material between conductive structures prevents galvanic reactions by blocking etchants and cleaning solutions from contacting interfaces between dissimilar metals, allowing for the use of different metals for each conductive structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If different metals are used for each conductive structure, then electrical characteristics can be optimized, but galvanic corrosion occurs between dissimilar metals

Engineering Contradiction:

Improveelectrical characteristicsVSAvoidgalvanic corrosion

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

An inter block dielectric material is introduced as an intermediary between dissimilar metal conductive structures. This dielectric layer physically separates the metals and prevents direct contact, thereby eliminating the galvanic corrosion pathway while allowing each metal to maintain its optimized electrical characteristics for specific applications

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of operation

If etchants and cleaning solutions contact interfaces between dissimilar metals, then cleaning effectiveness is improved, but galvanic reactions are triggered

Engineering Contradiction:

Improvecleaning effectivenessVSAvoidgalvanic reactions

Core Design Contradiction:

Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The inter block dielectric serves as a protective intermediary that blocks etchants and cleaning solutions from reaching the interface between dissimilar metals. This prevents galvanic reactions triggered by electrolyte contact while still allowing effective cleaning of accessible surfaces

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The presence of the inter block dielectric transforms a potential harm (inability to clean metal interfaces) into a benefit by preventing galvanic corrosion. The dielectric itself can be cleaned or removed if necessary, and its protective function outweighs the limitation on interface cleaning

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 solution effectively reduces or eliminates galvanic corrosion, enhances the electrical characteristics of the contact plugs, and improves the overall reliability of the integrated circuits by ensuring better contact between different metal regions.

Implementation Method 1

Methodology Applied

Scientific EffectPhysical barrier blocking:

Data Source

PatentUS12349395B2Inter block for recessed contacts and methods forming same

Publication Date: 2025.07.01 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

Embodiments provide a dielectric inter block disposed in a metallic region of a conductive line or source/drain contact. A first and second conductive structure over the metallic region may extend into the metallic region on either side of the inter block. The inter block can prevent etchant or cleaning solution from contacting an interface between the first conductive structure and the metallic region.