Gate Isolation Layer Air Gap for Lower FinFET Capacitance
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Solution Overview
Problem
The increased integration density of semiconductor devices leads to undesirably high capacitance due to the gate isolation layer, which is a challenge in FinFETs with three-dimensional structures, particularly during the replacement metal gate process.
Innovation Solution
Incorporating an air gap into the gate isolation layer to reduce capacitance, with a middle critical dimension greater than the top critical dimension, enhancing insulation efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the gate isolation layer is made solid to ensure structural integrity, then manufacturing reliability is improved, but capacitance increases due to material presence
Solution Approach 1:
The gate isolation layer is designed with an air gap (porous structure) instead of being completely solid. This air gap reduces the dielectric material volume, thereby reducing capacitance while maintaining the necessary structural integrity through the surrounding solid material framework.
Solution Approach 2:
The gate isolation layer becomes a composite structure combining solid material and air gap. This composite approach allows the structure to maintain mechanical strength from the solid portions while reducing capacitance through the low-dielectric-constant air region.
2Productivity
If the gate isolation layer width is reduced to increase integration density, then productivity is improved, but capacitance reduction is limited
Solution Approach 1:
Instead of uniformly reducing the entire gate isolation layer width, the invention introduces an air gap locally within the gate isolation layer. This local modification reduces capacitance without requiring a significant reduction in overall layer width, thus maintaining high integration density.
3Object-generated harmful factors
If the gate isolation layer is made thinner to reduce capacitance, then harmful factors are reduced, but manufacturing precision becomes more difficult to control
Solution Approach 1:
The gate isolation layer is segmented into solid material regions and an air gap region. This segmentation allows the solid portions to maintain sufficient thickness for manufacturability while the air gap provides additional capacitance reduction without requiring the entire layer to be thinner.
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
The air gap in the gate isolation layer effectively reduces capacitance, improving insulation between gate structures and maintaining high integration density in semiconductor devices.
Implementation Method 1
a gate isolation layer configured to separate a gate line may be disposed in a FinFET. With the downscaling of semiconductor devices to achieve high integration, capacitance due to the gate isolation layer may undesirably increase.
Data Source
AI summary
Semiconductor devices are provided. A semiconductor device includes a channel region that protrudes from a substrate. The semiconductor device includes a gate line on the channel region. Moreover, the semiconductor device includes a gate isolation layer that is between a first portion of the gate line and a second portion of the gate line. The gate isolation layer is in contact with the gate line and includes a gap that is in the gate isolation layer. Related methods of manufacturing a semiconductor device are also provided.