Self-Aligned Through Vias for Low-Resistance Semiconductor Routing
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Solution Overview
Problem
As semiconductor devices continue to integrate more components into a given area through reduced minimum feature sizes, challenges arise in signal routing resistance and capacitance, misalignment, and device defects due to the use of conventional interconnect structures.
Innovation Solution
The implementation of feedthrough vias, which are self-aligned to a feedthrough isolation structure, replacing conventional routing with shorter, wider conductive lines, reducing signal routing resistance and capacitance, and minimizing misalignment and defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional interconnect structures are used for signal routing, then device integration density can be maintained, but signal routing resistance and capacitance increase
Solution Approach 1:
The patent introduces through-vias that extend vertically through multiple interlayer dielectric layers, transitioning from planar routing to three-dimensional routing. This allows signals to bypass conventional horizontal routing paths, reducing routing resistance and capacitance while maintaining integration density through vertical stacking of interconnect layers.
Solution Approach 2:
The patent divides the interconnect structure into multiple segments: through-vias penetrating individual interlayer dielectric layers, separate contact regions, and distinct conductive pathways. This segmentation allows independent optimization of each routing segment, reducing overall signal resistance and capacitance while maintaining high integration density through modular stacking.
2Quantity of substance
If minimum feature sizes are reduced to increase integration density, then more components can be integrated, but misalignment and device defects increase
Solution Approach 1:
The patent forms contact holes and through-vias in sequential steps with predetermined depths and positions before final conductive layer deposition. This preliminary structuring establishes precise alignment references that guide subsequent processing steps, reducing misalignment errors even as feature sizes are reduced to increase integration density.
Solution Approach 2:
The patent introduces intermediary layers including adhesion layers and barrier layers between the substrate and conductive materials. These intermediary layers serve as buffer zones that compensate for dimensional variations and misalignment, reducing defect formation while allowing continued scaling for higher integration density.
3Device complexity
If conventional routing paths are used, then device structure can be maintained, but signal routing length increases causing higher resistance
Solution Approach 1:
The patent implements vertical through-vias that penetrate through interlayer dielectric layers to create direct vertical signal pathways, replacing longer horizontal routing paths. This three-dimensional routing architecture significantly reduces signal routing length and resistance while maintaining device structural integrity through systematic layer stacking and alignment.
Data Source
AI summary
Methods of forming through vias for providing connections between a front-side of a substrate and a backside of the substrate and semiconductor devices including the same are disclosed. In an embodiment, a semiconductor device includes a gate structure on a substrate; a first isolation feature extending partially through the gate structure; a first conductive feature extending through the first isolation feature; and a second conductive feature extending partially through the gate structure, the second conductive feature being electrically coupled to the first conductive feature.