In this paper we discuss the use of high-frequency acoustic waves (approximately 0.8-1 MHz, megasonic) as a means of enhancing cleaning efficiency for postetch polymer removal in the Cu/low-k dual damascene process. Attempts were made to integrate 0.13-mum technology Cu/low-k dual damascene structures without hard mask, by using acoustic agitation as a means of improving process margin over fencing issues associated with this integration scheme. We have demonstrated that it is possible to use this method on 0.13-mum technology Cu/low-k dual damascene structures without damage. Contact resistance yields of more than 90% were still achievable, although the processing time was reduced significantly with the use of megasonic enhancement. (C) 2004 Published by Elsevier B.V.