Optimization of damascene feature fill for copper electroplatingprocess

摘要

A copper electroplating process suitable for routine ICmanufacturing use must deliver Cu films that reproducibly fill deep,narrow damascene features. In this paper, several important factors suchas seed layer coverage, plating waveform (DC, reversed-pulse), andadditive chemistry formulation were examined in terms of their effect onthe elimination of localized void defects within filled structures. Acombination of two-step DC plating and custom additive chemistryenabling complete fill of 9:1 aspect ratio (AR), 0.13 μm trenches and5:1 AR, 0.18 μm vias was accomplished