Imaging Circuitry Scribe Line Support Structures
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Solution Overview
Problem
Conventional imaging systems face challenges in forming color filter array structures and experiencing damage during dicing operations due to the lack of silicon substrate material in scribe line regions, leading to non-uniform surfaces and potential cracking.
Innovation Solution
The implementation of through-oxide via structures and scribe line region support structures, along with deep trench isolation structures, to maintain substrate material in scribe line regions, enhance mechanical robustness, and reduce parasitic capacitance, while allowing for improved light guiding and alignment during dicing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If scribe line regions are devoid of silicon substrate material, then dicing operations can be performed, but the image sensor die surface becomes non-uniform and color filter array structures cannot be properly formed
Solution Approach 1:
The patent applies local quality by maintaining silicon substrate material specifically in the scribe line regions where it is needed for surface uniformity, while allowing substrate removal in other areas. This selective preservation of substrate material enables both proper color filter array formation and dicing operations.
Solution Approach 2:
The patent performs preliminary action by forming the scribe line region support structures before subsequent processing steps. This ensures that the substrate material is preserved in advance to maintain surface uniformity during color filter array formation and to prevent damage during later dicing operations.
2Manufacturing precision
If oxide material is disposed in scribe line regions, then substrate material is preserved, but the interface between oxide material and silicon substrate is prone to damage and cracking during dicing
Solution Approach 1:
The patent uses composite materials by combining silicon substrate material with scribe line region support structures in the scribe line regions. This composite structure maintains surface uniformity while the support structures are designed to prevent interface damage and cracking during dicing operations.
Solution Approach 2:
The scribe line region support structures act as intermediaries between the silicon substrate material and the external environment. These support structures protect the substrate-material interface from damage and cracking during dicing while allowing the substrate material to maintain surface uniformity.
3Ease of manufacture
If substrate material is removed in scribe line regions, then dicing is enabled, but mechanical robustness of the image sensor die is reduced
Solution Approach 1:
The patent applies local quality by preserving silicon substrate material specifically in the scribe line regions to maintain mechanical robustness, while allowing substrate removal in active device areas. The scribe line region support structures further reinforce this local preservation to prevent damage during dicing.
Solution Approach 2:
The patent performs preliminary action by forming scribe line region support structures before dicing operations. This preliminary reinforcement ensures that the substrate material in scribe line regions maintains sufficient mechanical strength to withstand dicing while enabling the dicing process itself.
Data Source
AI summary
An image sensor wafer may be stacked on top of a digital signal processor (DSP) wafer. The image sensor wafer may include multiple image sensor dies, whereas the DSP wafer may include multiple DSP dies. The stacked wafers may be cut along scribe line regions to dice the wafers into individual components. Each image sensor die may include through-oxide vias (TOVs) that extend at least partially into a corresponding DSP die. Scribe line support structures may be formed surrounding the scribe line regions. The scribe line support structures and the TOVs may be formed during the same processing step. The TOVs can also be formed through deep trench isolation structures.