The properties of copper conductive layers electroplated from a copper hexafluorosilicate electrolytic solution have been studied. The observed resistivity is in the region of 2.9 muOmega cm for an as-deposited copper layer electroplated from a conventional copper sulfate electrolytic solution. By electroplating from a copper hexafluorosilicate electrolytic solution on a low stress seed layer, a copper conductive layer with a larger grain size and lower stress can be obtained. A resistivity of 1.85 muOmega cm can be attained for such an as-deposited layer. This resistivity is much lower than the 2.8 muOmega cm of other as-deposited layers by conventional copper electroplating. (C) 2003 The Electrochemical Society.