YEZDI DORDI & PETER HEY, Applied Materials, Inc., Santa Clara, CA, USA
ABSTRACT
Copper electroplating has become the accepted process for depositing copper on semiconductor wafers. Achieving reliable via and trench filling is the principal challenge of the electroplating process, and this gap filling process is controlled by the kinetics of the copper plating reaction, which in turn is partially governed by the nature and concentration of trace amounts of organic additives in the electrolyte. Since additive concentrations are in the parts-per-million (ppm) range and are continuously depleted during the plating process as well as during system idle time, maintaining the correct electroplating bath composition is critical to achieving consistent void-free filling