Pulse-Reverse Electrodeposition of Cu for the Fabrication of Metal Interconnection I. Effects of Anodic Steps on the Competitive Adsorption of the Additives Used for Superfilling

초록

Cu electrodeposition and superfilling in the presence of organic additives have been widely researched. Nowadays, the reduction of interconnection dimensions raises issues, such as the reduction of electrical property and the difficulty of superfilling narrow features. Superfilling results from the competitive adsorption of organic additives, and the changes in their surface coverage. Therefore, modification of the adsorption state can improve the superfilling performance. Since anodic potential is applied during the pulse-reverse electrodeposition, it has the potential to considerably affect the adsorption of organic additives. In this research, the impacts of process parameters of pulse-reverse electrodeposition, such as deposition/anodic potentials and anodic time, on the competitive adsorption between PEG-Cl-and SPS are studied. It is confirmed that the anodic step promotes the displacement of PEG-Cl-by SPS at the early stage of electrodeposition, and it is intensified with more positive potential and longer anodic time. (C) 2013 The Electrochemical Society. All rights reserved.

키워드