Wafer-Sliced Fuse Layout for Seal-Preserving Test Access
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Solution Overview
Problem
Conventional fuses in integrated circuits are irreversible and do not allow for operations like signal transmission or grounding during the electrical wafer sorting phase without compromising the seal tightness of the integrated circuits.
Innovation Solution
An electrically conductive fuse is designed to extend through sealing rings in a semiconductor wafer, with a straddling portion that can be sliced, allowing for reversible electrical states while maintaining seal integrity by being electrically isolated from the sealing rings and substrate, and potentially forming part of the sealing ring structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional fuse structure is used, then the seal tightness of the integrated circuit is maintained, but the fuse cannot perform signal transmission or grounding operations during electrical wafer sorting
Solution Approach 1:
The fuse is segmented into multiple portions: a first portion inside the integrated circuit, a second portion passing through the sealing ring (electrically isolated), and a third portion outside the integrated circuit. This segmentation allows the fuse to extend beyond the sealing ring for external operations while the isolated second portion maintains seal integrity.
Solution Approach 2:
The second portion of the fuse acts as an intermediary element that physically connects the internal and external portions but is electrically isolated from the sealing ring. This intermediary structure enables signal transmission through the sealing ring region without compromising the electrical seal.
2Adaptability or versatility
If the fuse extends through the sealing ring, then signal transmission operations are enabled, but the seal tightness may be compromised
Solution Approach 1:
The electrical conductivity is extracted from the portion of the fuse that passes through the sealing ring. The second portion is made electrically insulating while maintaining physical continuity, thus removing the harmful electrical connection that would compromise the seal while preserving the mechanical structure needed for signal transmission.
3Adaptability or versatility
If the fuse is made reversible for operations during wafer sorting, then operational flexibility is improved, but the fuse structure becomes more complex
Solution Approach 1:
The multi-portion fuse structure serves multiple functions: the first portion provides internal connectivity, the second isolated portion maintains seal integrity while enabling external access, and the third portion provides external connectivity for wafer sorting operations. This universal structure replaces multiple separate components.
Data Source
AI summary
A semiconductor wafer includes first zones containing integrated circuits, each first zone including a substrate and a sealing ring at a periphery of the substrate. The first zones are separated from each other by second zones defining cutting lines or paths. The integrated circuit includes an electrically conductive fuse that extends between a first location inside the integrated circuit and a second location situated outside the integrated circuit beyond one of the cutting lines. This electrically conductive fuse includes a portion that passes through the sealing ring and another portion that straddles the adjacent cutting line. The portion of the fuse that passes through is electrically isolated from the sealing ring and from the substrate. The straddling portion is configured to be sliced, when cutting the wafer along the cutting line, so as to cause the fuse to change from an electrical on state to an electrical off state.