Overlapping Rectangular Vias for Multilayer Interconnect Thermal Dissipation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As semiconductor chips miniaturize, heat dissipation becomes a significant issue due to increased operating frequency and reduced thermal conductivity, leading to poor yield and property degradation such as deformation, breaking, and short-circuiting, as heat is poorly dissipated from intermediate interconnect layers.
Innovation Solution
A multilayer interconnect structure is implemented with rectangular contact vias aligned in the same direction to overlap each other, effectively creating a wide heat dissipation line between interconnect layers, enhancing thermal conductivity and heat dissipation from intermediate levels to upper and lower layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the operating frequency is increased to several hundreds of megahertz or higher, then the processing speed is improved, but Joule heat generated due to current passing through interconnect is substantially increased
Solution Approach 1:
The patent transitions from conventional offset via arrangements to an overlapping via configuration where vias in different interconnect layers are vertically aligned. This dimensional reorganization creates continuous heat dissipation pathways through the stack, transforming the thermal management approach from lateral to vertical heat flow, thereby effectively addressing the increased Joule heat generated at higher operating frequencies
Solution Approach 2:
The overlapping contact vias act as thermal intermediaries that bridge multiple interconnect layers. By aligning vias vertically across layers, the patent creates intermediary heat conduction paths that facilitate efficient heat transfer from higher-frequency, higher-heat-generating interconnect layers to lower layers with better heat dissipation capability
2Area of stationary object
If the interconnect width is reduced for miniaturization, then the chip area is reduced, but the heat dissipation effect is reduced
Solution Approach 1:
The patent compensates for reduced lateral heat dissipation (due to narrower interconnects) by exploiting the vertical dimension. Overlapping vias create extended heat conduction pathways in the thickness direction, allowing heat to dissipate through multiple layers rather than relying solely on lateral spread, thus maintaining effective heat dissipation despite miniaturization
Solution Approach 2:
The patent changes the thermal conduction parameter by creating continuous vertical heat paths through overlapping vias. This structural parameter change transforms the heat dissipation mechanism from primarily lateral conduction to include significant vertical conduction components, compensating for the reduced heat dissipation capability of narrower interconnects
3Speed
If a pore is formed in the interconnect insulating layer to lower the dielectric constant, then the interconnect delay is reduced, but the thermal conductivity is further degraded
Solution Approach 1:
The overlapping contact vias serve as thermal mediaries that bridge the thermal gap created by low-k insulating layers with pores. By providing continuous metal pathways through the low-k regions, the vias act as intermediary heat conduction channels, allowing heat to bypass the thermally resistive porous insulating materials while the pores continue to provide electrical isolation and reduced interconnect delay
4Area of stationary object
If the number of interconnect layers is increased to implement multilayer interconnection, then the chip area is reduced, but the heat dissipation capability is reduced
Solution Approach 1:
The patent exploits the vertical dimension created by multiple interconnect layers to enhance heat dissipation. By aligning vias vertically across layers, the configuration transforms the multilayer structure from a potential heat-trapping arrangement to a heat-dissipating stack, where each layer contributes to vertical heat conduction pathways, turning the increased layer count into an advantage for thermal management
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 improves heat dissipation from intermediate interconnect layers, reducing the likelihood of heat staying within the structure, thereby enhancing semiconductor device yield and minimizing property degradation.
Implementation Method 1
a stack structure in which a lower-layer interconnect in a first interconnect layer is connected to an upper-layer interconnect in a third interconnect layer... as for heat dissipation effect, a structure is implemented as if a wide heat dissipation line were provided between the lower-layer interconnect and the upper-layer interconnect, thereby increasing the thermal conductivity between levels
Implementation Method 2
the operating frequency of the semiconductor chips has dramatically increased to as high as about several hundreds of megahertz or higher, and Joule heat generated due to a current passing through an interconnect has substantially been increased
Data Source
AI summary
A semiconductor device having a multilayer interconnect structure allowing heat in an interconnect layer at an intermediate level to be effectively dissipated is provided. A lower-layer interconnect (13), an intermediate interconnect (23), an upper-layer interconnect (33), a first contact via (15) formed to electrically connect the lower-layer interconnect (13) to the intermediate interconnect (23), and a second contact via (25) formed to electrically connect the intermediate interconnect (23) to the upper-layer interconnect (33) are provided. When viewed from above, the first and second contact vias (15, 25) both have a rectangular shape with their long sides extending in the same direction, and overlap with each other.