Two-Port SRAM Jumper Structure for Misaligned Metal Routing
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Solution Overview
Problem
In deep sub-micron integrated circuit technology, the restricted design rules for metal line routing in advanced process nodes, such as 10 nm or below, lead to misalignment issues between SRAM cell regions and peripheral logic regions, preventing proper electrical connection due to uniform pitch and size requirements, which limits the bandwidth and efficiency of SRAM devices.
Innovation Solution
A jumper structure formed of conductive metal, combined with metal vias in adjoining via layers, is used to establish electrical connections between misaligned metal lines across different layers, allowing for alignment-independent interconnects and bridging the interface between SRAM and logic areas, thereby enabling efficient electrical connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If uniform pitch and size requirements are enforced for metal lines in advanced process nodes, then manufacturing precision is improved, but electrical connection between SRAM cell regions and peripheral logic regions deteriorates due to misalignment
Solution Approach 1:
The patent introduces an intermediary structure (jumper or via) between the first and second metal lines to establish electrical connection. This intermediary component bridges the misalignment gap caused by uniform pitch requirements, allowing the SRAM cell region and peripheral logic region to be electrically connected despite the manufacturing constraints.
2Manufacturing precision
If restricted design rules are adopted for metal line routing, then manufacturing precision is improved, but device complexity increases due to alignment-independent interconnect requirements
Solution Approach 1:
The patent transitions from planar routing to three-dimensional interconnection by utilizing multiple metal layers and vertical vias. This dimensional change allows the interconnect structure to bypass the limitations of uniform pitch rules in the planar domain, enabling alignment-independent connections through vertical stacking and lateral offset compensation in the third dimension.
3Manufacturing precision
If misalignment between metal lines is prevented, then manufacturing precision is improved, but productivity deteriorates due to limited bandwidth of SRAM devices
Solution Approach 1:
The patent segments the interconnect path into multiple independent components (first metal line, jumper, second metal line) that can be independently routed and aligned. This segmentation allows each component to be optimized separately, enabling the overall interconnect structure to achieve both manufacturing precision and high bandwidth by distributing the connection function across multiple segments rather than requiring perfect alignment of a single continuous path.
Data Source
AI summary
A static random access memory (SRAM) device is provided in accordance with some embodiments. The SRAM device comprises a plurality of two-port SRAM arrays, which comprise a plurality of two-port SRAM cells. Each two-port SRAM cell comprises a write port portion, a read port portion, a first plurality of metal lines located in a first metal layer, a second plurality of metal lines located in a second metal layer, a third plurality of metal lines located in a third metal layer a plurality of edge cells, a plurality of well strap cells, and a plurality of jumper structures. Each jumper structure comprises first, second, and third metal landing pads located in the second metal layer and electrically connecting metal lines of the first and third metal layers.