Single Mask Set for Interposer Fabrication
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Solution Overview
Problem
The complex and costly process of fabricating interposer substrate layers with through-silicon-vias for Stacked-Silicon Interconnect Technology (SSIT) products requires multiple fabrication steps and a different top cell level design database and photomask for each product, leading to increased engineering time and cost.
Innovation Solution
A single mask set is used for fabricating interposer wafers for multiple products through lithographic imaging steps, where each portion of the interposer design is printed by exposing specific regions while blocking others, allowing for the creation of larger, many-layered devices using multiple exposures of the same mask.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a separate photomask is used for each product, then product-specific fabrication precision is improved, but engineering time and cost increase
Solution Approach 1:
The patent applies universality by designing a single photomask that can fabricate interposer wafers for multiple different products. The mask includes multiple printing regions, each configured to form interposer designs for different products, allowing one mask to serve multiple functions and eliminate the need for product-specific masks.
Solution Approach 2:
The patent applies segmentation by dividing the photomask into multiple distinct printing regions, where each region contains the pattern for a specific product. During fabrication, only the relevant printing region is exposed for each product, enabling selective production from a single mask while maintaining product-specific precision.
2Manufacturing precision
If a separate photomask is used for each product, then product-specific fabrication precision is improved, but manufacturing cost increases
Solution Approach 1:
The patent applies universality by designing a single photomask that can fabricate interposer wafers for multiple different products. The mask includes multiple printing regions, each configured to form interposer designs for different products, allowing one mask to serve multiple functions and eliminate the need for product-specific masks.
Solution Approach 2:
The patent applies merging by combining multiple product-specific printing regions into a single photomask structure. This consolidation reduces the total number of masks required, lowering material costs, storage requirements, and engineering overhead while maintaining the ability to produce different products with high precision.
3Adaptability or versatility
If multiple lithographic imaging steps are used, then manufacturing flexibility is improved, but process complexity increases
Solution Approach 1:
The patent applies dynamics by implementing a selective exposure process where different printing regions of the mask are activated or deactivated based on the desired product. The lithographic system dynamically adjusts which regions are exposed during each imaging step, providing manufacturing flexibility without requiring physically different masks for each product.
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 reduces engineering time and cost by enabling the fabrication of interposer wafers for multiple products with similar architectures using a single mask set, while also allowing for the production of larger, more complex devices like field programmable gate arrays (FPGAs).
Implementation Method 1
forming the interposer design on a substrate using a plurality lithographic imaging steps. For each lithographic imaging step, at least one portion of the interposer design is printed by exposing at least one of the printing regions while blocking at least one other of the printing regions
Data Source
AI summary
A method for fabricating an interposer wafer includes providing at least one mask having printing regions for forming a plurality of interposer designs; selecting an interposer design; and forming the interposer design on a substrate using a plurality of lithographic imaging steps. For each lithographic imaging step, at least one portion of the interposer design is printed by exposing at least one of the printing regions while blocking at least one other of the printing regions.