Air-Gap Insulation Using Nanoparticles for Semiconductor Conductors
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Solution Overview
Problem
Conventional methods for forming air-gaps between adjacent conductors in semiconductor devices face issues with poor step coverage and reduced cross-sectional area due to non-conformal deposition of dielectric materials, which increases parasitic capacitance and signal crosstalk.
Innovation Solution
The use of nanoparticles with specific cross-sectional widths that prevent entry into the air-gaps, allowing for the formation of air-gaps with a substantial volume between adjacent conductors by depositing them over the conductors and sealing them with an insulating material, thereby maintaining a larger air-gap volume.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If non-conformal deposition methods are used to form air-gaps, then the deposition process is simpler, but the cross-sectional area of air-gaps is reduced and step coverage is poor
Solution Approach 1:
The patent segments the air-gap formation process into multiple sequential deposition steps with different deposition conditions. Each step deposits dielectric material with specific characteristics (conformal or non-conformal) to achieve different functions: initial conformal deposition for step coverage, followed by non-conformal deposition for air-gap formation, and final conformal deposition for sealing. This segmentation allows optimization of each step independently.
Solution Approach 2:
The patent performs preliminary conformal deposition of dielectric material around conductors before forming the air-gaps. This preliminary action ensures that the conductor surfaces are fully covered and provides a foundation for subsequent air-gap formation, preventing poor step coverage while enabling effective air-gap creation in later non-conformal deposition steps.
2Ease of manufacture
If air-gaps are formed by burning off material, then the process may be simpler, but the efficacy and reliability of air-gap formation has not been demonstrated
Solution Approach 1:
The patent replaces the thermal/chemical burning-off process with a controlled physical deposition and removal process. Instead of using high-temperature burning to create air-gaps, the method uses precise deposition of dielectric materials followed by selective removal, providing better control over air-gap dimensions and composition while maintaining process reliability.
Solution Approach 2:
The patent changes the deposition parameters (conformal vs. non-conformal, deposition thickness, deposition material composition) to control air-gap formation precisely. By adjusting these parameters across multiple deposition steps, the method achieves reliable air-gap formation with controlled dimensions without relying on uncertain burning-off processes.
3Strength
If conventional insulating material is deposited to completely fill spaces between conductors, then mechanical strength is improved, but parasitic capacitance increases due to reduced air-gap volume
Solution Approach 1:
The patent applies local quality by using different dielectric materials with different properties in different regions. The first dielectric material (lower permittivity) is placed in regions where minimizing parasitic capacitance is critical (near conductor surfaces), while the second dielectric material (higher mechanical strength) is used in regions where mechanical support is needed. This spatial differentiation of material properties simultaneously reduces parasitic capacitance and maintains mechanical strength.
Solution Approach 2:
The patent creates a composite insulating structure using two different dielectric materials with complementary properties. The composite structure combines a low-permittivity material for electrical performance (reducing parasitic capacitance) with a high-strength material for mechanical performance, achieving both goals that cannot be met by a single material alone.
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 effectively reduces parasitic capacitance and signal crosstalk by maintaining a larger air-gap volume between conductors, improving the mechanical strength and reducing leakage currents, while simplifying the fabrication process.
Implementation Method 1
depositing them over the conductors and sealing them with an insulating material
Data Source
AI summary
A semiconductor device and a method of forming it are disclosed in which at least two adjacent conductors have an air-gap insulator between them which is covered by nanoparticles of insulating material being a size which prevent the nanoparticles from substantially entering into the air-gap.