TSV Via Configuration for Uniform Current Density
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Solution Overview
Problem
Conventional through-semiconductor via (TSV) structures experience electromigration degradation due to high current density and local joule heating, leading to thermal and tensile stresses that can cause voids and increase the risk of damage, particularly at the surface where metal contacts a dielectric interface.
Innovation Solution
The integration of a plurality of vias within the dielectric layer, configured to create a substantially uniform current density throughout the TSV, by varying their size, shape, or material to distribute electrical resistance evenly, thereby reducing current crowding and electromigration risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a conventional TSV structure with a single metal layer is used, then the structure is simple, but high current density and local joule heating occur causing electromigration degradation
Solution Approach 1:
The patent divides the single metal layer into multiple metal layers (first metal layer and second metal layer) separated by a dielectric layer. This segmentation distributes the current flow across multiple pathways, reducing current density in any single TSV and preventing localized joule heating that causes electromigration.
Solution Approach 2:
A dielectric layer is introduced as an intermediary between the first and second metal layers. This dielectric layer enables the creation of multiple via pathways (first vias and second vias) that distribute current flow, while also providing thermal management and mechanical stress relief to prevent electromigration degradation.
2Reliability
If multiple vias are used to distribute current density, then electromigration resistance improves, but device complexity increases
Solution Approach 1:
The via structure is segmented into multiple discrete vias (first vias coupling the first metal layer to TSV, and second vias coupling the second metal layer to TSV). This segmentation creates multiple current pathways that distribute current density uniformly, reducing electromigration risk while maintaining a systematic and manufacturable structure.
Solution Approach 2:
The patent transitions from a two-dimensional single-layer via structure to a three-dimensional multi-layer via structure by adding vertical stacking of metal layers and dielectric layers. This dimensional expansion allows current to flow through multiple vertical pathways, distributing current density without requiring excessive lateral space.
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 effectively reduces the risk of electromigration damage by evenly distributing current density, minimizing thermal and tensile stresses, and preventing void formation in TSV structures.
Implementation Method 1
by varying their size, shape, or material to distribute electrical resistance evenly
Implementation Method 2
High current density and local joule heating in one portion of the TSV may cause the TSV to experience electromigration degradation
Implementation Method 3
Electromigration is caused primarily by frictional force between metal ions and flowing electrons
Data Source
AI summary
The present disclosure generally provides for integrated circuit (IC) structures with through-semiconductor vias (TSV). In an embodiment, an IC structure may include a through-semiconductor via (TSV) embedded in a substrate, the TSV having a cap; a dielectric layer adjacent to the substrate; a metal layer adjacent to the dielectric layer; a plurality of vias each embedded within the dielectric layer and coupling the metal layer to the cap of the TSV at respective contact points, wherein the plurality of vias is configured to create a substantially uniform current density throughout the TSV.