Multi-Dimension TSV Structure for 3DIC Heat Dissipation and Alignment
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Solution Overview
Problem
The challenge in three-dimensional integrated circuit (3DIC) devices is achieving sufficient thermal performance and alignment during bonding operations, particularly due to the obscuration of alignment markers during wafer inversion and the limitations of small-diameter through silicon via (TSV) structures, which compromise thermal conductivity and alignment accuracy as process technology nodes advance.
Innovation Solution
The implementation of multi-dimension TSV structures with a first columnar structure for electrical signaling and a second columnar structure for thermal management, where the second columnar structure is configured to enhance heat transfer and used for alignment purposes, allowing for improved thermal performance and reduced device size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If small-diameter TSV structures are used to reduce device size, then device footprint is reduced, but thermal conductivity deteriorates
Solution Approach 1:
The patent divides the thermal management function into separate dedicated thermal TSV structures distinct from signal TSV structures. This segmentation allows thermal vias to be optimized for heat conduction (larger diameter) while signal vias maintain small diameters for low capacitance, resolving the contradiction between device size and thermal performance
Solution Approach 2:
The patent introduces an additional dimensional aspect by creating multi-layer via structures that extend through multiple die layers. Thermal TSVs are strategically positioned and connected across layers to create enhanced thermal pathways, adding a vertical dimension to heat dissipation that complements the horizontal device footprint reduction
2Ease of manufacture
If wafer inversion is performed during bonding, then alignment markers become obscured, but bonding process requires inversion
Solution Approach 1:
The patent creates alignment features (such as alignment rings or markers) on the backside of wafers before the inversion step. These pre-formed features remain visible after inversion, enabling accurate alignment measurements to be performed on the inverted wafer without the marker obscuration problem
Solution Approach 2:
The patent uses alignment features that are copied or replicated across multiple wafers in the stack. By having identical alignment markers on corresponding wafers, the system can perform relative alignment measurements even when individual markers are obscured, as the pattern repetition provides reference points
3Device complexity
If TSV structures serve both electrical signaling and thermal management, then device complexity is reduced, but thermal performance deteriorates
Solution Approach 1:
The patent segments the TSV functionality into distinct thermal TSV structures and signal TSV structures. Thermal TSVs are designed with larger diameters and optimized materials for heat conduction, while signal TSVs maintain small diameters for electrical performance. This functional segmentation resolves the contradiction by allowing each via type to be optimized for its specific purpose
Solution Approach 2:
The patent applies different material compositions and structural properties to different regions of the TSV structures. Thermal TSVs use materials with high thermal conductivity (such as copper or tungsten) and larger cross-sections, while signal TSVs use materials optimized for electrical signaling. This local differentiation enables simultaneous optimization of both thermal and electrical performance
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 approach enhances thermal performance by increasing heat transfer rates, maintaining junction temperatures under high-temperature conditions, prolonging device life, and reducing resource consumption in manufacturing, while improving alignment accuracy and efficiency.
Implementation Method 1
The first columnar structure may include a low electrical capacitance and be configured for electrical signaling within the 3DIC device. The second columnar structure may be configured to provide power to integrated circuitry of the 3DIC device and also be configured to conduct heat through the 3DIC device for thermal management of the 3DIC device.
Implementation Method 2
This approach enhances thermal performance by increasing heat transfer rates, maintaining junction temperatures under high-temperature conditions
Data Source
AI summary
Some implementations described herein include systems and techniques for fabricating a multi-dimension through silicon via structure in a three-dimensional integrated circuit device. The multi-dimension through silicon via structure includes a first columnar structure having a first width and a second columnar structure including a second width that is greater relative to the first width. The first columnar structure may include a low electrical capacitance and be configured for electrical signaling within the three-dimensional integrated circuit device. The second columnar structure may be configured to provide power to integrated circuitry of the three-dimensional integrated circuit device and also be configured to conduct heat through the three-dimensional integrated circuit device for thermal management of the three-dimensional integrated circuit device. Additionally, a pattern including the second columnar structure may be used for alignment purposes.