Through-Via Annular Trench Layout for Lower Parasitic Capacitance
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Solution Overview
Problem
Existing semiconductor apparatuses face challenges in enhancing reliability, particularly in reducing parasitic capacitance and improving yield, due to the formation of parasitic capacitance between through vias and the semiconductor substrate.
Innovation Solution
The semiconductor apparatus includes a semiconductor substrate with a through hole and an annular trench surrounding its circumference, featuring a rear-surface insulating film, a rear-surface redistribution wire, and a solder mask, which enhances insulation and durability, reduces parasitic capacitance, and improves signal transfer performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If through vias are formed in a semiconductor substrate, then signal transfer performance is improved, but parasitic capacitance is formed between the through vias and the semiconductor substrate which deteriorates signal transfer performance
Solution Approach 1:
The patent extracts and removes the harmful parasitic capacitance by forming annular trenches around the through holes, isolating the conductors from the semiconductor substrate. This separation eliminates the capacitive coupling between the through via conductors and the substrate, thereby removing the harmful effect while preserving the signal transfer function.
Solution Approach 2:
The patent introduces an intermediary structure (annular trench with insulating material) between the through via conductors and the semiconductor substrate. This intermediary layer acts as a mediator that prevents direct electrical interaction, thereby eliminating parasitic capacitance formation while allowing the through vias to maintain their signal transfer function.
2Reliability
If annular trenches are formed around through holes to reduce parasitic capacitance, then reliability is improved, but manufacturing complexity increases
Solution Approach 1:
The patent segments the through via structure by dividing it into distinct components: the through hole, the annular trench surrounding it, and the insulating material filling the trench. This segmentation allows each component to be optimized independently for reliability while maintaining a systematic manufacturing approach that manages complexity through modular construction.
Solution Approach 2:
The patent employs a nested structure where the annular trench is formed within the semiconductor substrate surrounding the through hole, and insulating material is nested within the annular trench. This nested configuration achieves enhanced reliability through multiple protective layers while utilizing the same manufacturing space efficiently, thereby managing complexity.
3Productivity
If the semiconductor substrate is thinned to enhance integration, then productivity is improved, but mechanical strength deteriorates
Solution Approach 1:
The patent employs composite material structures by combining the semiconductor substrate with annular trenches filled with insulating materials. This composite construction provides mechanical reinforcement to the thinned substrate, compensating for the loss of strength due to thinning while enabling higher integration through reduced substrate thickness requirements.
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 configuration enhances the reliability and yield of the semiconductor apparatus by reducing parasitic capacitance, improving insulation properties, and facilitating high-speed signal transfer while allowing for a high degree of integration.
Implementation Method 1
a rear-surface insulating film that covers the rear surface of the semiconductor substrate... enhancing the insulation property
Implementation Method 2
the second rear-surface insulating film may include a fixed electric charge film. This produces the effect of reducing the influence of defects at an interface or the front surface
Data Source
AI summary
Provided is a semiconductor apparatus including a semiconductor substrate having a front surface on which a wiring layer is formed, a through hole that penetrates the semiconductor substrate, a through wire formed along a side surface of the through hole, and an annular trench that surrounds a circumference of the through hole when seen in a direction perpendicular to a rear surface of the semiconductor substrate which is on a side opposite to the front surface and that has formed therein a cavity when seen in a direction parallel to a rear surface.