We have investigated and compared the characteristics of Ru etching by employing O-2/Cl-2 inductively coupled plasma (ICP) and helicon plasma. We have studied the variation of Ru etch rate and the Ru to SiO, etch selectivity with varying the gas flow ratio, the bias power, and the total gas flow rate. With optimizing the process for two different plasma sources, we have obtained higher etch rate of Ru electrode by using ICP, compared to by using helicon plasma. We demonstrated the etching slope of greater than 85degrees in terms of real pattern, using ICP. X-ray photoelectron spectroscopy (XPS) revealed that the Ru surface etched using ICP contained less amount of 0 element than using helicon plasma. (C) 2004 Elsevier B.V. All rights reserved.