aveni's conformal Rhea copper seed was used in recent work at CEA-Leti, as part of the IRT Nanoelec 3D Program, for the fabrication of Through Silicon Vias (TSVs) at an unprecedented 12:1 aspect ratio. TSV aspect ratios have been limited to 10:1, due to limited reactant transport and slower deposition rates associated with conventional dry deposition methods, such as physical vapor deposition (PVD). These PVD constraints can lead to subsequent discontinuous or incomplete TSV filling, which affect reliability and electrical yield. The 12:1 TSVs (10µm diameter x 120µm high) using Rhea seed, achieved 100% electrical yield, with resistances that correlate very well to theoretical values. Electrografting™, aveni’s wet deposition technology, creates superior-quality metal layers, such as Rhea copper seed, which is instrumental to achieving higher aspect ratio TSVs.