화학공학소재연구정보센터
Journal of the Electrochemical Society, Vol.157, No.1, C24-C29, 2010
Corrosion Behavior of Copper Thin Films in Organic HF-Containing Cleaning Solution for Semiconductor Applications
The corrosion behavior of electrochemically deposited copper thin films in deaerated and non-deaerated commercial cleaning solutions containing HF was investigated. Potentiodynamic polarization experiments were carried out to determine active, active passive, passive, and transpassive regions. Corrosion rates were calculated from Tafel slopes. The addition of hydrogen peroxide to the solution and its influence on corrosion was also investigated by employing inductively coupled plasma-mass spectroscopy (ICP-MS) and X-ray photoelectron spectroscopy (XPS). The ICP-MS and potentiodynamic methods yielded comparable Cu dissolution rates. Surface analysis using atomic force microscopy and scanning electron microscopy, performed before and after the cleaning solution treatment, did not reveal any indication of pitting corrosion. The presence of hydrogen peroxide in the cleaning solution led to more than an order of magnitude suppression of copper dissolution rate. We ascribe this phenomenon to the formation of interfacial CuO detected by XPS on the wafer surface that dissolves at a slower rate in dilute HF. (C) 2009 The Electrochemical Society. [DOI:10.1149/1.3245999] All rights reserved.