Void defect reduction after chemical mechanical planarization of trenches filled by direct/pulse plating

Abstract

The effect of various frequencies of pulse current (PC) on the crystal orientation of copper deposit was investigated in this article. When PC frequency was lower than 100 Hz, high (111) (200) ratio after annealing was achieved and the amount of void defects was reduced after chemical mechanical planarization (CMP) process. In addition, the behaviors of additives depends on the pulse frequency were also studied and resulted in the different characteristics of copper deposits at various pulse frequencies. We therefore propose a modified deposition approach comprising direct current (dc) and PC which can reduce the void defects after CMP process based on the above experimental results. © 2007 The Electrochemical Society.