Elimination of copper line damages for damascene process

摘要

After the first layer of copper has been deposited and polished (to form the pattern of copper damascene conducting lines) a layer of Ta or TaN/Cu is deposited. Another thin layer of copper is deposited thereby filling existing pores and recesses in the polished copper lines. A second CMP is applied to the surface of the second deposited layer of copper, this second CMP removes the redundant copper from the space where the Inter Metal Dielectric (IMD) layer will be created. Prior to the deposition of the second layer of copper, a (brief) etchback of the (surface of the) first layer of copper can be performed in order to enhance copper surface integrity and thereby improve the deposition of the second layer of copper. A layer of TaN/Ta and a layer of seed copper can be deposited within the openings for the damascene conducting lines prior to the deposition of these lines.