Recessed Contact Inter-Block Structure Against Galvanic Corrosion
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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 dissimilar metals used for recessed conductive structures, which can lead to increased resistivity and reliability issues due to galvanic reactions during etching and cleaning processes.
Innovation Solution
The introduction of an inter block dielectric material between recessed conductive structures prevents direct contact and etchant access, reducing galvanic effects by forming an inter block within the source/drain contact plugs, allowing the use of different metals for each conductive structure and enhancing the adherence and stability of the conductive structures through a bottom-up deposition process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If dissimilar metals are used for recessed conductive structures, then material versatility and electrical performance are improved, but galvanic corrosion occurs during etching and cleaning processes
Solution Approach 1:
An inter block dielectric material is introduced as an intermediary between dissimilar metals in recessed conductive structures. This dielectric layer prevents direct contact between different metals during etching and cleaning processes, eliminating galvanic corrosion while allowing the use of different metal materials for optimal electrical performance in each conductive structure
Solution Approach 2:
The conductive structure is segmented into multiple regions with different dielectric materials. Specifically, a first dielectric material is used in a first recessed conductive structure and a second dielectric material is used in a second recessed conductive structure, allowing each segment to be optimized independently for electrical performance while preventing galvanic interaction through dielectric isolation
2Ease of manufacture
If direct contact between dissimilar metals is allowed, then manufacturing simplicity is maintained, but galvanic reactions increase resistivity
Solution Approach 1:
The inter block dielectric serves as a mediator that prevents galvanic reactions between dissimilar metals. By introducing this dielectric layer, the patent achieves both manufacturing simplicity (through a straightforward deposition process) and precise electrical resistance control (by eliminating galvanic corrosion that would otherwise increase resistivity)
3Reliability
If inter block dielectric is introduced, then galvanic corrosion is prevented, but device structure complexity increases
Solution Approach 1:
The inter block dielectric is introduced as a thin intermediary layer that prevents galvanic corrosion without significantly increasing device complexity. The dielectric is deposited conformally and planarized, integrating smoothly into existing manufacturing processes while providing effective galvanic isolation
Solution Approach 2:
The patent controls the thickness and material properties of the inter block dielectric to optimize protection against galvanic corrosion while minimizing impact on device performance and complexity. By adjusting dielectric thickness and material selection, the solution achieves reliable corrosion prevention with minimal structural overhead
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 galvanic corrosion, improves the electrical resistance, and enhances the structural integrity of the conductive structures by preventing etchant and cleaning agent contact between dissimilar metals, enabling the use of different materials for each conductive structure while maintaining low resistivity and stability.
Implementation Method 1
The introduction of an inter block dielectric material between recessed conductive structures prevents direct contact and etchant access, reducing galvanic effects
Implementation Method 2
enhancing the adherence and stability of the conductive structures through a bottom-up deposition process
Data Source
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.