Robust dual damascene process
 A robust dual damascene process is disclosed where the substructure in a substrate is protected from damage caused by multiple etchings required in a damascene process by filling a contact or via hole opening with a protective material prior to the forming of the conductive line opening of the damascene structure having an etch-stop layer separating a lower and an upper dielectric layer. In the first embodiment, the protective material is partially removed from the hole opening reaching the substructure prior to the forming of the upper conductive line opening by etching. In the second embodiment, the protective material in the hole is removed at the same time the upper conductive line opening is formed by etching. In a third embodiment, the disclosed process is applied without the need of an etch-stop layer for the dual damascene process of this invention. 
Taiwan Semiconductor Manufacturing Company
H H G
H01L H01L G03F
inventional inventional inventional
Cheng-Ming Jenn Ming Yu-Hua Cheng-Tung
Wu Huang Lee Lin