aveni® S.A. Announces Breakthrough Electrical Yield Results for 12:1 TSVs
Collaboration with CEA-Leti, within the framework of IRT Nanoelec, successfully integrates Electrografted™ Rhea™ copper seed layer into process flow
MASSY, France – Jan. 23, 2018 – aveni S.A., developer and manufacturer of market-disrupting wet deposition technologies and chemistries for 3D through silicon via (TSV) packaging and 2D interconnects, today announced that CEA-Leti has successfully fabricated TSVs at an unprecedented 12:1 aspect ratio and achieved 100% electrical yield using aveni’s Rhea copper seed. This study used 12:1 TSVs with a diameter of 10µm x 120µm high.
“aveni’s Electrografted wet metal deposition technology creates superior-quality conformal metal layers, such as the Rhea copper seed used in this research at CEA-Leti, as part of the IRT Nanoelec 3D Program. For the TSV dimensions tested, the electrical measurements correlate very well to theoretical yield. We were quite pleased with the results,” noted Frédéric Raynal, aveni’s chief technical officer.
TSVs are a type of interconnect that vertically connect multiple layers (stacked chips) to create high-density electrical connections. They are most commonly used in high-performance applications like high-bandwidth memory (HBM) stacks integrated with graphics processing units (GPUs) on silicon interposers, as well as high-performance computing. High-density interconnects are important because they enable greater processing power in a smaller device footprint.
Aspect ratio, which describes the ratio of the height of cylindrically shaped via features to the via diameter, has generally been limited to 10:1 for advanced TSVs, due to constraints with conventional dry deposition methods such as physical vapor deposition (PVD). At aspect ratios greater than 10:1 and as TSV diameters are reduced, PVD suffers from limited reactant transport and slower deposition rates. This leads to incomplete or discontinuous filling inside the TSVs, which in turn affects electrical yield and reliability.
Bruno Morel, aveni’s CEO, commented, “This is the first report of TSVs at a 12:1 aspect ratio achieving perfect electrical yield. Reported studies have demonstrated 10:1 TSVs, but nothing has yet been reported at this feature size and 12:1 aspect ratio. Once again, this work demonstrates the long-range extendibility of aveni’s Electrografting technology. Our roadmap continues to push ahead to realize smaller-diameter TSVs at higher aspect ratios.”
The complete findings will be published soon.