Effect of CoxMoy as Single Barrier Layer on Properties of Directly Electroplated Copper Films

Abstract

In this study, resistivity, texture and self-annealing behaviors of directly electroplated copper films on CoxMoy liner/barrier layers were systematically studied. Cu with lower resistivity, lower resistance drop caused by self-annealing and stronger (111) texture can be electroplated on Co compared with CoMo layers and Mo. This phenomenon can be explained by the different nucleation densities of Cu on liner/barrier during the initial process of electrodeposition (ECD). Comparison was also made between Cu films electroplated on CoxMoy and Cu seed layer/CoxMoy. It is found that texture of direct-ECD Cu was closely related to nucleation density, while texture of ECD Cu on Cu/CoxMoy was affected by texture inheritance from Cu seed to ECD Cu films.