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Crack Deflector Kerf Fills

IP.com Disclosure Number: IPCOM000250390D
Publication Date: 2017-Jul-10
Document File: 3 page(s) / 42K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a novel, step-like kerf structure and that deflects an incoming crack above, away from the Si substrate and the weak point in the crackstop/moisture barrier.

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Title Crack Deflector Kerf Fills Abstract Disclosed is a novel, step-like kerf structure that deflects an incoming crack above, away from the Si substrate and the weak point in the crackstop/moisture barrier. Problem Advanced integrated circuits (ICs) using Copper (Cu) metallization along with low-k and ultra-low-k (ULK) dielectrics are susceptible to fails due to weakness in crackstop/moisture barrier integrity. The wafer singulation process often causes cracks in the dielectric materials at the diced edge of the chip. These cracks may travel to the crackstop/moisture barrier and cause delamination. If the crackstop is not mechanically strong enough, then the delamination/crack can reach the chip interior and cause device failure. Occasionally, the cracks may dive down into Silicon (Si) before reaching crackstop. The crack can then break through the Si underneath the crackstop and fail the chip. Solution/Novel Contribution The proposed solution is a novel kerf structure. A step-like fill structure deflects the incoming crack above, away from the Si substrate and the weak point in the crackstop/moisture barrier. The step-like fill structure starts from the lowest metallization level and progressively stacks up high metallization levels to guide and deflect the crack from Si and interfaces/areas. Method/Process Scattered fill structures (not a continuous wall) fill the kerf as much as possible. This reduces the chance that the crack dives down into Si before reaching cracksto...