Air Spacer Structure for Source/Drain Capacitance Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As semiconductor devices continue to shrink in size, challenges arise in reducing parasitic capacitance and improving isolation between source/drain regions, which affect device performance.
Innovation Solution
The formation of sealed air gaps and spacers adjacent source/drain regions in semiconductor devices, achieved by depositing a multi-layer stack, etching to form nanostructures and recesses, and filling these with inner spacer layers to reduce parasitic capacitance and enhance isolation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If minimum feature sizes are reduced to increase integration density, then more components can be integrated into a given area, but parasitic capacitance increases and isolation between source/drain regions deteriorates
Solution Approach 1:
The patent extracts and removes dielectric material from the region between source/drain regions to create air gaps. This extraction of the harmful dielectric medium reduces parasitic capacitance while maintaining the high integration density achieved through minimized feature sizes.
Solution Approach 2:
The patent applies different properties to different regions: air gaps are created specifically in the isolation regions between source/drain structures, while dielectric layers remain in other areas. This localized modification reduces parasitic capacitance without compromising overall device integration density.
2Productivity
If minimum feature sizes are reduced to increase integration density, then more components can be integrated into a given area, but isolation between source/drain regions deteriorates
Solution Approach 1:
The patent extracts dielectric material to create air gaps between source/drain regions, improving isolation. The air gaps act as effective barriers that enhance electrical isolation while allowing tight spacing for high integration density.
Solution Approach 2:
The patent changes the dielectric constant parameter in the isolation regions by replacing high-k dielectric material with air (k≈1). This parameter change enhances isolation effectiveness while maintaining the spatial constraints required for high integration density.
Data Source
AI summary
Semiconductor devices including air gaps between source/drain regions and a semiconductor substrate and methods of forming the same are disclosed. In an embodiment, a semiconductor device includes a semiconductor substrate; a first channel region on the semiconductor substrate; a gate structure on the first channel region; a first source/drain region adjacent the gate structure and the first channel region; a first inner spacer layer between the first source/drain region and the semiconductor substrate in a first direction perpendicular to a major surface of the semiconductor substrate; and a first air gap between the first source/drain region and the first inner spacer layer in the first direction.