Shared Pad-Bridge Layout for Single-Mask 3D IC Stacks
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Solution Overview
Problem
The semiconductor industry faces challenges in further shrinking minimum feature sizes in integrated circuits, leading to increased costs and reduced throughput due to the need for separate photomasks for different frontside pad/bridge layouts in three-dimensional (3D) ICs.
Innovation Solution
Implementing a shared frontside pad/bridge layout across multiple IC dies, which allows for the use of a single set of photomasks, reducing costs and increasing throughput by maintaining the same layout across all dies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If separate photomasks are used for different frontside pad/bridge layouts in 3D ICs, then manufacturing flexibility and adaptability are improved, but manufacturing costs increase and throughput decreases
Solution Approach 1:
The patent merges the frontside pad/bridge layouts of multiple IC dies into a single shared layout. Instead of using separate photomasks for each die, a common photomask set is used to form identical pad and bridge structures across all dies in the 3D IC stack, thereby reducing mask complexity and improving throughput
Solution Approach 2:
The patent implements a universal frontside pad/bridge layout that serves multiple IC dies simultaneously. The same pad and bridge structures are reused across different dies, allowing a single photomask design to function for the entire 3D IC assembly rather than requiring die-specific mask designs
2Adaptability or versatility
If separate photomasks are used for different frontside pad/bridge layouts in 3D ICs, then layout customization for individual dies is improved, but manufacturing costs increase
Solution Approach 1:
The patent combines the layout design of multiple dies into a single standardized frontside pad/bridge layout. This merging eliminates the need for separate photomask designs for each die, directly reducing photomask fabrication costs and simplifying the manufacturing process
Solution Approach 2:
The patent applies homogeneity by making the frontside pad/bridge layouts identical across all IC dies in the 3D structure. This standardized approach reduces manufacturing complexity and cost by eliminating variations that would require separate photomask designs
Data Source
AI summary
Various embodiments of the present disclosure are directed towards a shared frontside pad/bridge layout for a three-dimensional (3D) integrated circuit (IC), as well as the 3D IC and a method for forming the 3D IC. A second IC die underlies the first IC die, and a third IC die underlies the second IC die. A first-die backside pad, a second-die backside pad, and a third die backside pad are in a row extending in a dimension and overlie the first, second, and third IC dies. Further, the first-die, second-die, and third-die backside pads are electrically coupled respectively to individual semiconductor devices of the first, second, and third IC dies. The second and third IC dies include individual pad/bridge structures at top metal (TM) layers of corresponding interconnect structures. The pad/bridge structures share the shared frontside pad/bridge layout and provide lateral routing in the dimension for the aforementioned electrical coupling.