3D Interconnect Routing Layout for Reduced-Height Standard Cells
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The miniaturization of integrated circuits leads to challenges in providing sufficient routing resources due to limitations in metal pitch, which restricts the number of metal tracks within a given cell height, resulting in design rule violations and inadequate power and signal routing.
Innovation Solution
The proposed solution involves advanced layout designs that optimize metal track placement and via contacts across multiple layers, allowing for reduced mask usage and increased feature density without violating design rules, using techniques like nature end processes and LSLE, to accommodate smaller cell heights and enhance routing resources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If metal pitch is reduced to increase the number of metal tracks within a given cell height, then routing resources are improved, but design rule violations occur and manufacturing reliability deteriorates
Solution Approach 1:
The patent introduces a third metal layer (M3) above the traditional two-layer (M1, M2) structure, transforming the routing problem from a 2D plane to a 3D space. This dimensional expansion allows additional power and signal tracks without reducing the pitch of existing layers, thereby maintaining design rule compliance while increasing routing capacity. The M3 layer provides dedicated routing resources that do not interfere with the spacing requirements of lower layers.
Solution Approach 2:
The patent segments the routing function across multiple metal layers, with M1 and M2 handling certain routing tasks and M3 handling others. This segmentation allows each layer to be optimized independently for its specific routing needs, preventing congestion and avoiding design rule violations that would occur if all routing were attempted on fewer layers with reduced pitch.
2Area of moving object
If cell height is reduced to increase feature density, then device miniaturization is achieved, but routing resources become insufficient
Solution Approach 1:
By adding the M3 metal layer, the patent effectively increases the vertical dimension of the routing space without increasing the cell height. This allows more routing resources to be packed into the same footprint by utilizing the third dimension (z-axis) rather than compressing features in the x-y plane, thereby maintaining feature density while increasing routing capacity.
Solution Approach 2:
The patent nests multiple routing functions within the vertical stack of metal layers. The M1, M2, and M3 layers are nested in the vertical direction, with each layer providing additional routing resources. This nesting allows the circuit to achieve high feature density in the horizontal plane while accumulating routing resources through the vertical stack.
3Ease of manufacture
If mask usage is reduced to simplify manufacturing, then production costs are lowered, but design flexibility and routing options are limited
Solution Approach 1:
The M3 metal layer serves multiple functions: it provides additional power routing, signal routing, and can be used for both intra-cell and inter-cell connections. This multi-functionality allows the same structural addition (M3 layer) to address multiple routing needs simultaneously, maintaining design flexibility without requiring separate specialized structures for each function.
Data Source
AI summary
One aspect of this description relates to an integrated circuit. In some aspects, the integrated circuit includes a first pattern metal layer, a second pattern metal layer disposed over the first pattern metal layer, wherein the second pattern metal layer includes a second plurality of metal tracks extending in a first direction, and a third pattern metal layer disposed between the first pattern metal layer and the second pattern metal layer, the third pattern metal layer including a first metal track segment and a second metal track segment shifted in a second direction from the first metal track segment, wherein the second plurality of metal tracks, and at least a portion of each of the first metal track segment and the second metal track segment are within a double cell height in the second direction.