Robert Preisser, Atotech Deutschland, Berlin, Germany

ABSTRACT

The introduction of copper metallization into semiconductor manufacturing has been a significant step in process technology and device scaling. However, the wet electro-deposition technology used suffers from a number of drawbacks. Impurities deposited on the copper anode from organic additives in the electrolyte solution can subsequently be released and deposited on the wafer, leading to killer-defect particles. Also, gas bubbles from the electrolytic decomposition of water can be trapped in the deposited metal, leading to further process issues.