Air-Gap Metal Line Structure for Lower Parasitic Capacitance
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Solution Overview
Problem
As electronic devices are scaled down, parasitic capacitance between metal lines increases, leading to signal loss and adversely affecting circuit speed response.
Innovation Solution
Incorporating an air gap between metal lines and a middle structure composed of three different materials to reduce parasitic capacitance, including an intermediate dielectric layer, mask layer, and supporting portions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the gap between upper metal line and lower metal line is reduced to scale down electronic devices, then device size is reduced, but parasitic capacitance increases causing signal loss
Solution Approach 1:
The patent extracts the harmful dielectric material from the region between metal lines and replaces it with air gaps. By removing the solid dielectric material that causes parasitic capacitance and replacing it with air (which has minimal dielectric constant), the patent eliminates the source of signal loss while maintaining the reduced device dimensions.
Solution Approach 2:
The patent introduces air gaps (porous structure) between metal lines instead of using solid dielectric material. These air gaps create a porous or hollow structure that reduces parasitic capacitance while maintaining mechanical support through surrounding dielectric layers, thereby reducing signal loss in scaled-down devices.
2Loss of energy
If air gaps are introduced between metal lines, then parasitic capacitance is reduced, but manufacturing complexity increases
Solution Approach 1:
The patent performs preliminary actions by forming sacrificial structures and defining air gap regions during earlier manufacturing stages before final metal deposition. By pre-establishing the air gap geometry through patterned dielectric layers and sacrificial materials, the subsequent formation of metal lines becomes simpler, as the air gap structure is already in place to guide the manufacturing process.
Solution Approach 2:
The patent uses intermediate dielectric layers and sacrificial materials as mediators to create air gaps. These intermediate structures serve as temporary placeholders or guiding frameworks during manufacturing, enabling precise air gap formation without requiring complex direct patterning methods. The intermediate layers are later removed or modified to reveal the final air gap structure.
Data Source
AI summary
A circuit structure and a method of manufacturing a circuit structure are provided. The circuit structure includes a first metal line and a second metal line. The second metal line is disposed over the first metal line. At least one air gap is disposed between the first metal line and the second metal line.