Wiring Structure With Air Gaps For Parasitic Capacitance Reduction
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Solution Overview
Problem
As semiconductor devices become more highly integrated, the parasitic capacitance between metal wirings increases due to reduced spacing, which is not effectively reduced by existing insulation layers with low dielectric constants, especially in deeper device integration levels.
Innovation Solution
A wiring structure is developed with a conductive pattern, a first insulation layer pattern, and a second insulation layer pattern, where the second insulation layer pattern has a smaller distance from the conductive pattern, and both insulation layers have low dielectric constants, with the first layer being more prone to plasma etch damage, creating air gaps to reduce parasitic capacitance while maintaining low resistance and structural stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If metal wirings are arranged at small spacing to increase integration, then device integration degree is improved, but parasitic capacitance between adjacent metal wirings increases
Solution Approach 1:
The patent extracts the harmful dielectric material between the conductive pattern and insulation layer pattern, replacing it with air gaps. This removes the source of parasitic capacitance while maintaining the structural integrity and electrical functionality of the wiring system.
Solution Approach 2:
The patent introduces air gaps (porous spaces) between the conductive pattern and insulation layer pattern, as well as within the insulation layer patterns themselves. These air gaps have effectively low dielectric constants, reducing parasitic capacitance while allowing the structure to maintain mechanical stability.
2Object-generated harmful factors
If insulation layer with low dielectric constant is used to reduce parasitic capacitance, then parasitic capacitance is reduced, but effectiveness is limited in deeper device integration
Solution Approach 1:
The patent applies different dielectric properties to different locations: air gaps are created specifically where parasitic capacitance is most problematic (between conductive pattern and insulation layer pattern, and within insulation layer patterns), while other areas maintain appropriate insulation. This localized approach maximizes capacitance reduction effectiveness.
Solution Approach 2:
The patent creates a composite structure combining conductive patterns, insulation layer patterns with low dielectric constant materials, and air gaps. This composite wiring structure leverages the advantages of both solid insulation materials and air gaps to achieve superior parasitic capacitance reduction.
3Object-generated harmful factors
If air gaps are introduced to reduce parasitic capacitance, then parasitic capacitance is reduced, but structural stability may be compromised
Solution Approach 1:
The patent uses thin insulation layer patterns with low dielectric constants that can conform to the presence of air gaps while maintaining structural integrity. These thin film structures provide both electrical insulation and mechanical support, bridging the air gaps and preventing structural collapse.
Solution Approach 2:
The composite structure combines rigid conductive patterns, flexible insulation layer patterns, and air gaps in a way that the insulation layers act as structural bridges. This composite design distributes mechanical stresses and maintains overall structural stability despite the presence of air gaps.
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 proposed wiring structure effectively reduces parasitic capacitance and maintains low resistance, enhancing electrical characteristics and integration degree in semiconductor devices.
Implementation Method 1
the parasitic capacitance between adjacent metal wirings can be considerably increased
Implementation Method 2
an insulation layer between the wirings can be provided using a material having a low dielectric constant (i.e., low-k material)
Data Source
AI summary
A wiring structure includes a conductive pattern on a substrate, a first insulation layer pattern between adjacent conductive patterns and a second insulation layer pattern on the first insulation layer pattern. The first insulation layer pattern is separated from the conductive pattern by a first distance to provide a first air gap. The second insulation layer pattern is spaced apart from the conductive pattern by a second distance substantially smaller than the first distance to provide a second air gap. The wiring structure may have a reduced parasitic capacitance while simplifying processes for forming the wiring structure.