Semiconductor Seal Ring Varying Via Pitch
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Semiconductor devices face challenges with low-k interlayer dielectrics, which lack mechanical strength and moisture resistance, leading to issues during the CMP process and potential delamination, especially when porous materials are used, resulting in reduced chip performance and increased vulnerability to moisture intrusion.
Innovation Solution
The semiconductor device incorporates a seal ring region with varying via and interconnect pitches between layers, specifically narrowing these in lower layers to enhance mechanical strength, adhesion, and moisture resistance, while maintaining the seal ring size within limits by optimizing the metal content and using a barrier insulating layer for improved moisture resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If low-k materials are used to form the interlayer dielectric, then the dielectric constant is reduced and crosstalk between interconnect lines is reduced, but the film strength and adhesion properties deteriorate
Solution Approach 1:
The patent applies different via pitches in different via layers to address local quality requirements. Specifically, the first via layer has a first via pitch while the second via layer has a second via pitch that is different from the first, allowing optimization of mechanical strength and adhesion properties in specific regions where low-k materials are used
2Ease of manufacture
If the seal ring region size is determined according to upper layer interconnects and vias, then the upper layers can be properly formed, but the seal ring region excessively expands
Solution Approach 1:
The patent applies local quality by implementing different via pitches in different via layers. The first via layer has a first via pitch and the second via layer has a second via pitch, allowing optimization of seal ring region dimensions to prevent excessive expansion while maintaining upper layer formation capability
Data Source
AI summary
Mechanical strength and moisture resistance of a multilayer interconnect structure is to be improved. A semiconductor device includes a circuit region and a seal ring region formed around the circuit region, on a semiconductor substrate. The seal ring region includes a plurality of interconnect layers including interconnect lines and a plurality of via layers including a plurality of slit vias stacked on one another, and a pitch between the slit vias in at least one of the via layers (lower or middle layer) is different from a pitch between the slit vias in other via layers (upper layer).