抄録
Sigificant reduction of liner thickness for Cu electroplating in advancing LSI interconnection technology is required, so that direct Cu electroplating on Ru liner is investigated to replace the present Cu electroplating on Cu seed. More rapid aging of Ru liner than Cu seed causes larger roughness on plating without pretreatment. We studied Ru surface condition, Cu/Ru interface and Cu plating surface, found that there are <10nm voids on Cu/Ru interface that causes large roughness on plating. An electrochemical pretreatment, which is superior for processing time and coc, was done and resulted in good trench filling of 80nm line width.
