Process integration of CVD Cu as a seed layer for Cu electroplating and a plug-fill application

CVD Cu film has been evaluated as a seed layer for Cu electroplating and a plug-fill application for back-end Cu metallization in 0.18 /spl mu/m technologies. Excellent step coverage and via plug-fill with CVD Cu were routinely obtained. CVD Cu film showed the enhanced seed layer performance compared to an ionized PVD Cu seed layer. It was found that only 40 /spl Aring/ PVD Cu interlayer between the TaN and CVD Cu layer is enough to obtain low via contact resistance. The scheme of the CVD Cu seed formation followed by Cu electroplating showed approximately 20% lower via resistance as compared to that of the CVD Cu plug-fill followed by Cu electroplating.