Semiconductor Airgap Layout for Lower Off-State Capacitance
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Solution Overview
Problem
High off-state capacitance in semiconductor arrangements leads to increased time delay and decreased switching performance due to device and wiring capacitances.
Innovation Solution
Incorporating an airgap with a low dielectric constant between key components of the semiconductor arrangement, such as between contacts and gate structures, to reduce capacitance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional dielectric materials are used between contacts and gate structures, then structural integrity and electrical insulation are maintained, but off-state capacitance increases leading to increased time delay and decreased switching performance
Solution Approach 1:
The patent changes the dielectric constant parameter by replacing conventional dielectric materials (with higher k-values) with airgap structures (with k≈1). This parameter change directly reduces the capacitance between contacts and gate structures, thereby reducing time delay and improving switching performance without sacrificing structural integrity or electrical insulation.
2Reliability
If airgap is introduced to reduce capacitance, then off-state capacitance decreases improving switching performance, but structural complexity and fabrication difficulty increase
Solution Approach 1:
The patent applies the extraction principle by removing the dielectric material entirely from specific regions to create airgaps between contacts and gate structures. Instead of introducing a complex new material system, the invention extracts the harmful dielectric component and replaces it with air, simplifying the material system while achieving the desired capacitance reduction and improving switching performance.
3Reliability
If airgap is introduced to reduce capacitance, then off-state capacitance decreases improving switching performance, but manufacturing precision requirements increase
Solution Approach 1:
The patent employs preliminary action by forming mandrels and sacrificial structures during earlier fabrication steps that define the future airgap regions. These preliminary structures guide subsequent etching and material removal processes, ensuring precise airgap formation without requiring high-precision direct airgap creation. This approach embeds the precision requirements into well-established fabrication processes.
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
Reduces off-state capacitance by 40% or more, improving resistance-capacitance time delay and radio frequency switching performance.
Implementation Method 1
Incorporating an airgap with a low dielectric constant between key components of the semiconductor arrangement, such as between contacts and gate structures, to reduce capacitance
Data Source
AI summary
A semiconductor arrangement includes a gate structure disposed between a first source/drain region and a second source/drain region and a first contact disposed over the first source/drain region. The semiconductor arrangement includes a second contact disposed over the second source/drain region and an airgap disposed between the first contact and the second contact and over the gate structure.