Dual Seal Ring Layout With Dummy Patterns for Process Uniformity
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Solution Overview
Problem
Existing seal ring structures in semiconductor technologies are limited in their ability to be fully closed or partially closed depending on chip architecture, which can affect the protection and interconnectivity of IC dies during fabrication and dicing processes.
Innovation Solution
The implementation of a dual seal ring structure, where an outer seal ring encloses multiple inner seal rings, with the inner seal rings being selectively open or closed based on chip architecture, and the use of dummy patterns in redundant regions to reduce process variations and improve chip area utilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single seal ring structure is used, then the structure is simple and easy to manufacture, but it cannot provide selective opening/closing functionality for different chip architectures
Solution Approach 1:
The seal ring is divided into multiple independent inner seal rings and an outer seal ring. Each inner seal ring can be independently configured as open or closed based on chip architecture requirements, while the outer seal ring remains closed. This segmentation enables selective opening/closing functionality without requiring a completely different seal ring design for each application.
Solution Approach 2:
Multiple inner seal rings are nested within the outer seal ring structure. The inner seal rings are positioned inside the enclosed space of the outer seal ring, creating a nested configuration. This nesting approach allows the inner seal rings to be selectively opened or closed while maintaining the overall sealed structure provided by the outer seal ring.
2Manufacturing precision
If redundant regions are left empty in the seal ring structure, then the manufacturing process is simpler, but process variations increase and chip area utilization decreases
Solution Approach 1:
Dummy patterns are selectively placed only in the redundant regions between the inner seal rings and the outer seal ring, while leaving the circuit regions and interconnect areas free of dummy patterns. This local placement approach improves process variation control in the redundant regions without interfering with the functional areas of the chip.
Solution Approach 2:
Dummy patterns that replicate the structure and material properties of actual circuit features are placed in redundant regions. These dummy patterns serve as copies that match the electrical and physical characteristics of real circuits, thereby improving process uniformity and reducing variations without adding functional complexity.
3Reliability
If inner seal rings are fully closed, then protection against moisture and contamination is maximized, but interconnectivity between adjacent circuit regions is prevented
Solution Approach 1:
The seal ring system is segmented into multiple independent inner seal rings within a closed outer seal ring. This segmentation allows each inner seal ring to be independently configured - some can remain closed for maximum protection, while others can be opened to enable interconnectivity between adjacent circuit regions, all within the same chip structure.
Solution Approach 2:
The inner seal rings are designed with dynamic configurability, allowing their open/closed state to be determined based on the specific chip architecture and interconnect requirements. This dynamic approach enables the seal ring structure to adapt to different design needs rather than being fixed in a single state.
Data Source
AI summary
A semiconductor structure includes first and second inner seal rings each having a first section and a second section substantially perpendicular to the first section. The semiconductor structure further includes an outer seal ring. The outer seal ring has a third section, and a fourth section, and a fifth section. The semiconductor structure further includes dummy patterns substantially uniformly distributed in each of regions between the first inner seal ring and the outer seal ring and between the second inner seal ring and the outer seal ring.