Backside Dummy Via Thermal Paths for Dense Semiconductor Chips
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Solution Overview
Problem
As technology nodes shrink in semiconductor devices, the increased transistor density leads to higher operating temperatures due to reduced chip area for thermal dissipation, necessitating improved heat dissipation mechanisms.
Innovation Solution
Thermal conductive paths are established from heat-generating components like transistors to the exterior of the chip through dummy features in the interconnect structure on the semiconductor chip's backside and front-side, enhancing heat dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If transistor density is increased to improve integration density, then productivity is improved, but temperature increases due to reduced thermal dissipation area
Solution Approach 1:
The patent introduces thermal dissipation paths that extend in the vertical dimension through multiple interconnect layers, rather than relying solely on horizontal chip area. Dummy conductive features are stacked across different interconnect layers to create three-dimensional thermal conduction paths from the device layer through the interconnect structure to the substrate, effectively utilizing the Z-dimension for heat removal.
Solution Approach 2:
The patent employs dummy conductive features as intermediary thermal conduction elements between the heat-generating device layer and the substrate. These dummy features, integrated within the interconnect structure, serve as thermal mediators that conduct heat away from active devices without interfering with electrical functionality, thereby resolving the thermal management challenge.
2Productivity
If chip area is reduced to improve integration density, then productivity is improved, but thermal dissipation capability deteriorates
Solution Approach 1:
The patent compensates for reduced horizontal thermal dissipation area by creating vertical thermal conduction paths through multiple interconnect layers. Dummy conductive features are distributed across different layers and connected vertically, transforming the thermal dissipation problem from a two-dimensional surface issue to a three-dimensional volume-based solution.
Solution Approach 2:
The patent merges the electrical interconnect function with the thermal management function by integrating dummy conductive features within the existing interconnect structure. These dummy features are embedded in dielectric layers alongside functional interconnects, combining structural, electrical, and thermal management roles into a unified multi-layer architecture.
3Temperature
If dummy features are added to improve thermal dissipation, then temperature management is improved, but device complexity increases
Solution Approach 1:
The patent achieves multi-functionality by designing dummy conductive features that simultaneously serve thermal management and structural purposes within the interconnect architecture. These features are formed using the same deposition and patterning processes as functional interconnects, allowing them to provide thermal conduction while maintaining mechanical support and electrical isolation functions.
Solution Approach 2:
The patent utilizes parameter changes in the interconnect structure, specifically varying the material composition and geometric dimensions of dummy conductive features across different layers to optimize thermal conductivity while controlling complexity. By adjusting parameters such as metal layer thickness, dummy feature spacing, and dielectric material thermal properties, effective thermal management is achieved without proportionally increasing structural complexity.
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 effectively manages operating temperature increases by providing efficient thermal management, compensating for the challenges of reduced chip area and increased transistor density.
Implementation Method 1
Thermal conductive paths are established from heat-generating components like transistors to the exterior of the chip
Data Source
AI summary
A device includes a device layer comprising a first transistor; a first interconnect structure on a front-side of the device layer; and a second interconnect structure on a backside of the device layer. The second interconnect structure includes a first dielectric layer on the backside of the device layer; a contact extending through the first dielectric layer to a source/drain region of the first transistor; a conductive line electrically connected to the source/drain region of the first transistor through the contact; and a thermal dissipation path thermally connected to the device layer, the thermal dissipation path extending to a surface of the second interconnect structure opposite the device layer. The thermal dissipation path comprises a dummy via.