Liner-Lined Single Diffusion Break for FinFET Epitaxial Protection
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Solution Overview
Problem
In advanced semiconductor technologies, the fabrication of single diffusion breaks for FinFET structures is challenging due to damage or removal of epitaxial source and drain regions during deep trench etch processes, leading to smaller source/drain epitaxial volume and increased contact resistance, which degrades device performance.
Innovation Solution
A single diffusion break structure is created in a substrate between adjacent gate structures, filled with an insulator material and lined with a liner material, which protects the epitaxial regions from damage during the trench etching process, maintaining the source and drain profiles and reducing defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a deep trench etch process is used to create single diffusion breaks by removing dummy gate structures, then the single diffusion break is formed, but the epitaxial source and drain regions are damaged or removed, resulting in smaller source/drain epitaxial volume and increased contact resistance
Solution Approach 1:
A liner material is introduced as an intermediary layer between the trench etch process and the epitaxial source/drain regions. This liner material protects the sensitive epitaxial regions from direct exposure to the harsh etching conditions, preventing damage and removal of the source/drain regions while still allowing the trench to be formed for the single diffusion break.
Solution Approach 2:
The liner material is deposited beforehand on the sidewalls of the trench before the trench is fully etched and before the insulator material is filled. This pre-established protective layer cushions the epitaxial source and drain regions against the harmful effects of the deep trench etch process, ensuring their integrity is maintained throughout the manufacturing process.
2Ease of manufacture
If the dummy gate structure is removed to create the deep trench undercut, then the single diffusion break is achieved, but the source and drain epitaxial volume is reduced, degrading device performance
Solution Approach 1:
The liner material serves as a protective intermediary that allows the trench to be formed without compromising the volume of the epitaxial source and drain regions. By lining the trench walls, it prevents the etch process from undercutting into and removing the valuable epitaxial material, thereby maintaining the required source/drain epitaxial volume for optimal device performance.
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 approach maintains device performance even at smaller technology nodes, such as the 10 nm node and beyond, by preventing damage to epitaxial source and drain regions and reducing contact resistance.
Implementation Method 1
a liner material lining the undercut region... which protects the epitaxial regions from damage during the trench etching process
Implementation Method 2
the single diffusion break filled with an insulator material
Data Source
AI summary
The present disclosure relates to semiconductor structures and, more particularly, to single diffusion cut for gate structures and methods of manufacture. The structure includes a single diffusion break extending into a substrate between diffusion regions of adjacent gate structures, the single diffusion break filled with an insulator material and further comprising an undercut region lined with a liner material which is between the insulator material and the diffusion regions.