FinFET Interconnect Structure With Adhesion Layer for Delamination Control
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Solution Overview
Problem
Existing interconnect structures in semiconductor devices face challenges in achieving optimal adhesion between conductive features and dielectric layers, leading to issues such as shrinkage and delamination during processing, particularly in high aspect ratio trench-via structures.
Innovation Solution
The implementation of an adhesion layer, such as titanium nitride, between the dielectric layer and conductive features to enhance adhesion and prevent shrinkage, combined with controlled etching processes to maintain desired trench-via structure profiles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing interconnect structures are used without adhesion layers, then the fabrication process is simpler, but adhesion between conductive features and dielectric layers deteriorates, leading to shrinkage and delamination
Solution Approach 1:
An adhesion layer is introduced as an intermediary between the dielectric layer and conductive features. This adhesion layer acts as a mediator that bonds to both the dielectric and conductive materials, preventing delamination and shrinkage without requiring fundamental changes to the interconnect structure architecture.
Solution Approach 2:
The interconnect structure employs composite material layers including dielectric material, adhesion layer, and conductive material in a multi-layer composite structure. Each material is selected for its specific properties: dielectric for insulation, adhesion layer for bonding, and conductive material for electrical connectivity, creating a composite structure that achieves superior overall performance.
2Productivity
If high aspect ratio trench-via structures are formed, then device density increases, but structural integrity deteriorates due to shrinkage and delamination
Solution Approach 1:
The adhesion layer serves as a critical intermediary in high aspect ratio trench-via structures, providing mechanical support and preventing shrinkage of the via walls. This mediator layer maintains the structural integrity of narrow, deep vias enabling higher device density without compromising stability.
Solution Approach 2:
The adhesion layer is deposited beforehand to cushion and protect the dielectric-conductive interface from stress and deformation during subsequent processing steps. This prior cushioning prevents delamination and maintains structural integrity throughout fabrication, especially in high aspect ratio structures where stress concentrations are critical.
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
Improves adhesion and reduces delamination, allowing for more reliable and efficient formation of interconnect structures with reduced resistance and improved structural integrity.
Implementation Method 1
The implementation of an adhesion layer, such as titanium nitride, between the dielectric layer and conductive features to enhance adhesion and prevent shrinkage
Data Source
AI summary
A semiconductor device structure and method for forming the same are provided. The semiconductor device structure includes a first metal layer formed over a substrate and a dielectric layer formed over the first metal layer. The semiconductor device structure further includes an adhesion layer formed in the dielectric layer and over the first metal layer and a second metal layer formed in the dielectric layer. The second metal layer is electrically connected to the first metal layer, and a portion of the adhesion layer is formed between the second metal layer and the dielectric layer. The adhesion layer includes a first portion lining with a top portion of the second metal layer, and the first portion has an extending portion along a vertical direction.