Air Gap Interconnections for Semiconductor Reliability
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Solution Overview
Problem
Highly integrated semiconductor devices face reliability issues due to increased parasitic capacitance and hydrogen atom retention, which affect their performance and integration capabilities.
Innovation Solution
The implementation of interconnections with air gaps and barrier dielectric patterns, along with spacers, reduces parasitic capacitance and hydrogen retention by creating a structure where air gaps are formed between interconnections, and spacers cover the barrier dielectric patterns, minimizing the distance between interconnections and preventing upper dielectric layer intrusion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If semiconductor devices are highly integrated to meet demand for higher speed and lower power consumption, then productivity and energy efficiency are improved, but parasitic capacitance increases causing reliability deterioration
Solution Approach 1:
The patent introduces air gaps that segment the continuous dielectric medium between interconnections into discrete regions. This segmentation reduces the parasitic capacitance by creating low-dielectric-constant regions (air) between adjacent conductive interconnections, thereby resolving the reliability issue caused by high integration density
Solution Approach 2:
The patent changes the dielectric parameter of the medium between interconnections from solid dielectric material to air (dielectric constant ≈ 1). This parameter change significantly reduces parasitic capacitance while maintaining the high integration density, thus improving reliability without sacrificing productivity
2Area of stationary object
If interconnections are placed closer together to increase integration, then area is reduced, but parasitic capacitance between adjacent interconnections increases
Solution Approach 1:
The patent applies local quality by introducing air gaps specifically in the regions between adjacent interconnections where parasitic capacitance is generated. The air gaps are localized to the critical areas between interconnections while maintaining close spacing overall, thus reducing harmful parasitic capacitance without increasing chip area
Solution Approach 2:
The air gap acts as an intermediary layer between adjacent interconnections. This intermediary region with low dielectric constant mediates the electromagnetic interaction between interconnections, reducing parasitic capacitance while allowing the interconnections to remain closely spaced for high integration
3Ease of manufacture
If conventional dielectric structures are used between interconnections, then manufacturing is simple, but hydrogen atom retention causes reliability deterioration
Solution Approach 1:
The patent extracts the solid dielectric material from the regions between interconnections and replaces it with air gaps. This extraction removes the source of hydrogen atoms that would otherwise be retained in the dielectric material and cause reliability issues, while the air gap formation process is integrated into existing fabrication flows
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 solution enhances the reliability and integration of semiconductor devices by reducing parasitic capacitance, signal delay, and hydrogen-related reliability deterioration, allowing for more compact and efficient semiconductor designs.
Implementation Method 1
An air gap may be disposed between the interconnections adjacent to each other
Implementation Method 2
barrier dielectric patterns disposed on top surfaces of the interconnections, respectively
Data Source
AI summary
Semiconductor devices and methods of fabricating the same are provided. The semiconductor device may include interconnections extending in a first direction on a substrate and spaced apart from each other in a second direction perpendicular to the first direction, barrier dielectric patterns disposed on top surfaces of the interconnections, respectively, and an upper interlayer dielectric layer disposed on the interconnection. Respective air gaps are disposed between adjacent ones of the interconnections.