Uniform-Conductivity Seal Ring Layout to Avoid Epitaxial Over-Etch
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Solution Overview
Problem
Existing seal ring structures in semiconductor technologies face challenges in stability and reliability due to damage from misalignments and over etching during epitaxial structure formation, particularly when different types of epitaxial structures are involved.
Innovation Solution
The implementation of a seal ring structure with all epitaxial structures of the same material and conductivity type, such as all p-type or all n-type, to prevent inadvertent damage during subsequent processing steps, ensuring uniformity and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If different types of epitaxial structures are formed in the seal ring region, then the functionality of the seal ring is enhanced, but the stability and reliability deteriorate due to damage from misalignments and over etching
Solution Approach 1:
The patent applies homogeneity by forming all epitaxial structures in the seal ring region with the same material composition and conductivity type (either all n-type or all p-type). This uniform approach eliminates the problems of misalignment damage and over-etching that occur when different epitaxial structures are present, while still providing the necessary protective functionality of the seal ring.
2Object-affected harmful factors
If multiple types of epitaxial structures are used in the seal ring, then the protection capability is improved, but the manufacturing precision deteriorates due to alignment issues
Solution Approach 1:
The patent resolves the manufacturing precision issue by using homogeneous epitaxial structures throughout the seal ring region. Since all epitaxial structures have the same material properties and conductivity type, the formation process does not require precise differentiation between different structure types, thereby eliminating alignment precision problems while maintaining effective protection against moisture and contamination.
3Reliability
If different conductivity types of epitaxial structures are formed, then the seal ring performance is enhanced, but the processability deteriorates due to over etching
Solution Approach 1:
The patent improves processability by forming all epitaxial structures with the same conductivity type (either all n-type or all p-type). This homogeneous approach simplifies the fabrication process by eliminating the need for selective etching and differentiation between different conductivity types, thereby preventing over-etching damage while still achieving effective seal ring performance.
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 enhances the processability and stability of the seal ring by eliminating damage from differing epitaxial structures, thereby improving the protection of semiconductor circuits from moisture and mechanical stress.
Implementation Method 1
epitaxial structures over the fin rings in the seal ring region
Data Source
AI summary
A semiconductor structure according to the present disclosure includes a circuit region disposed over a substrate and a seal ring region disposed over the substrate and completely surrounding the circuit region. The circuit region includes first fins, second fins, n-type epitaxial structures over the first fins, and p-type epitaxial structures over the second fins. The seal ring region includes fin rings extending completely around the circuit region, epitaxial rings disposed over and extending parallel to the fin rings. All of the epitaxial rings over all of the fin rings in the seal ring region are p-type epitaxial rings.