Scribe Seal Crack Arrest Structure for Semiconductor Dicing
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Solution Overview
Problem
During the dicing process of semiconductor wafers, cracks in insulator layers can propagate from the scribe street into integrated circuit dies, causing damage and moisture incursion, leading to corrosion and delamination issues.
Innovation Solution
The implementation of scribe seals with conductive vias extending through insulator layers and crack arrest structures, including an opening in the passivation layer, to prevent crack propagation by forming a vertical conductor structure that interrupts the continuity of brittle insulator layers and reduces moisture exposure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If mechanical sawing is used to separate integrated circuit devices from the semiconductor wafer, then singulation can be achieved, but cracks form in the insulator layers at the kerf lane edge and can propagate into the integrated circuit dies
Solution Approach 1:
The patent divides the scribe street region into multiple segments by introducing scribe seals and crack arrest structures. These structures create discrete zones that interrupt crack propagation paths, segmenting the continuous insulator layer into isolated sections that cannot transmit cracks to adjacent dies
Solution Approach 2:
The patent introduces scribe seals and crack arrest structures as intermediary elements between the kerf lane and the integrated circuit dies. These intermediary structures act as buffer zones that absorb and stop crack energy before it can reach the active die areas, protecting the dies from mechanical damage
2Productivity
If laser scribing followed by mechanical break is used for dicing, then separation can be achieved, but cracks in the insulating layers can still occur and propagate from the kerf line into the integrated circuit dies
Solution Approach 1:
The patent applies preliminary action by forming scribe seals and crack arrest structures before the dicing process. These pre-formed structures create predetermined crack arrest zones that will intercept and stop cracks before they can propagate into the dies during the subsequent laser scribing and mechanical breaking operations
3Reliability
If scribe seals with conductive vias extending through insulator layers are implemented, then crack propagation can be prevented, but device complexity increases
Solution Approach 1:
The patent applies multi-functionality by designing the scribe seal structure to serve multiple purposes: the conductive vias and conductor layers not only provide electrical connectivity for testing and handling but also act as crack arrest structures. This eliminates the need for separate dedicated crack prevention structures, reducing overall complexity
Solution Approach 2:
The patent merges the electrical test structure functions with the mechanical crack prevention functions into a single integrated scribe seal structure. The conductor layers and vias that would normally be added for electrical purposes are positioned and configured to simultaneously serve as barriers to crack propagation, combining two functional requirements into one structure
Data Source
AI summary
Disclosed embodiments include an integrated circuit having a semiconductor substrate with insulator layers and conductor layers overlying the semiconductor substrate. A scribe region overlying the semiconductor substrate and a periphery of the integrated circuit includes a crack arrest structure and a scribe seal. The crack arrest structure provides first vertical conductor structure that surrounds the periphery of the integrated circuit. The scribe seal is spaced from and surrounded by the crack arrest structure and provides a second vertical conductor structure. The scribe seal includes first and second vias spaced from each other and connected to one of the conductor layers. The first via is a trench via and the second via is a stitch via, with the second via being located closer to the crack arrest structure than the first via.