Copper has been deposited for filling sub-0.5 mu m trenches by using electroplating. Electroplating with pulse plating conditions provides the high deposition rate (0.5-1 mu m/min) and defect-free filling the 0.25 mu m trenches and vias of high aspect ratio (>4:1). Enhanced copper electroplating at the trench bottom has been achieved. The median grain size of electroplated copper was measured to be about 1 mu m and the lognormal standard deviation is about 0.4 mu m. Strong <111> texture was observed in electroplated Cu film. Low stress of electroplated Cu films and excellent adhesion of plated Cu to sputtered Cu seed were observed.
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