Bottom-Up Copper Filling of Millimeter Size Through Silicon Vias.

摘要: This work demonstrates void-free Cu filling of millimeter size Through Silicon Vias (mm-TSV) in an acid copper sulfate electrolyte using a combination poloxamine suppressor and chloride, analogous to previous TSV that were order magnitude smaller size. For high chloride concentration (i.e., 1 mmol/L) bottom-up deposition is demonstrated with the growth front being convex shape. Instabilities profile arise as approaches free-surface due coupling non-uniform hydrodynamics. The reentrant notches at bottom TSVs caused by intentional over-etching during fabrication negatively impact results. In contrast, from low electrolytes 80 μmol/L) proceeds passive-active transition on via sidewalls. given applied potential location fixed time concave nature reflecting gradient surface coverage. Application suitable wave form enables sidewall be systematically advanced thereby giving rise TSV.