Continuous Metal Crack Stop for IC Delamination
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Solution Overview
Problem
Integrated circuits (ICs) face challenges in resilience against delamination cracks during processing and wear, as existing crack stops may not effectively prevent or slow the propagation of cracks from the perimeter edge to the active devices.
Innovation Solution
The implementation of a continuous metal crack stop structure that extends through multiple layers, including an insulator, capping layer, and inter-layer dielectric, positioned proximate to the perimeter edge of the IC, to impede or prevent delamination cracks from propagating to the active devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If dummy materials (crack stops) are formed near the perimeter edge to prevent crack growth, then crack propagation is slowed or prevented, but cracks may circumvent the crack stop
Solution Approach 1:
The patent transitions from conventional two-dimensional crack stops (confined to a single metal layer) to a three-dimensional continuous crack stop that extends vertically through multiple metal layers and intermediate dielectric layers. This dimensional extension creates a comprehensive barrier that prevents cracks from circumventing the crack stop by propagating through adjacent layers, thereby resolving the limitation of traditional crack stops.
Solution Approach 2:
The continuous crack stop structure is formed by nesting conductive material across multiple metal layers and intermediate dielectric layers, creating a hierarchical barrier system. The crack stop extends from the first metal layer through the first intermediate dielectric layer to the second metal layer, forming a nested configuration that blocks crack propagation paths at multiple levels simultaneously.
2Reliability
If a continuous metal crack stop extends through multiple layers, then crack propagation is effectively blocked, but device complexity increases
Solution Approach 1:
The continuous crack stop structure serves multiple functions simultaneously: it acts as a crack propagation barrier across multiple layers, provides electrical connectivity between metal layers through vias, and maintains structural integrity during dicing and packaging processes. By integrating these functions into a single unified structure, the patent reduces overall device complexity while achieving superior crack resistance.
Solution Approach 2:
The patent merges the crack stop function with existing metal layers and vias in the interconnect structure. The continuous crack stop is formed by extending conductive material from first metal layer 124 through intermediate dielectric layer 122 to second metal layer 134, utilizing the same conductive material and fabrication processes already present in the device, thereby minimizing additional complexity.
Data Source
AI summary
An integrated circuit (IC) structure is disclosed. The structure can include: an insulator positioned over a device layer; a capping layer positioned over the insulator; an inter-layer dielectric (ILD) positioned over the capping layer; a first metal wire positioned over the ILD, and outside an active area of the IC structure; a continuous metal crack stop in contact with, and interposed between, the first metal wire and the device layer, such that the continuous metal crack stop extends through at least the insulator, the capping layer, and the ILD; a second metal wire positioned over the ILD, and within the active area of the IC structure; and two vias vertically coupled to each other and interposed between the second metal wire and the device layer, such that the two vias extend through at least the insulator, the capping layer, and the ILD.