Study of ruthenium and ruthenium oxide's electrochemical properties and application as a copper diffusion barrier

As a very promising material of copper diffusion barrier for next generation microelectronics, Ru has already obtained a considerable attention recently. In this dissertation, we investigated ruthenium and ruthenium oxide electrochemical properties and the application as a copper diffusion barrier.; Cu UPD on the RuOx formed electrochemically was first observed. Strong binding interaction, manifesting by the observed Cu UPD process, exists between Cu and Ru as well as its conductive ruthenium oxide. Since UPD can be conformally formed on the electrode surface, which enable Ru and RuO x has a potential application in the next generation anode. The [Cl -] and pH dependent experiment were conducted, both of them will affect UPD Cu on Ru oxide. We also found the Cu deposition is thermodynamically favored on RuOx formed electrochemically.; We have studied the Ru thin film (5nm) as a copper diffusion barrier. It can successfully block Cu diffusion annealed at 300°C for 10min under vacuum, and fail at 450°C. We think the silicidation process at the interface between Ru and Si. PVD Cu/Ru/Si and ECP Cu/Ru/Si were compared each other during cupper diffusion study. It was observed that ECP Cu is easy to diffuse through Ru barrier. The function of RuOx in diffusion study on Cu/Ru/Si stack was discussed.; In pH 5 Cu2+ solution, Ru and Pt electrochemical behavior were investigated. A sharp difference was observed compared to low pH value. The mechanism in pH 5 Cu2+ solution was interpreted. An interesting compound (posnjakite) was obtained during the electrochemical process. An appropriate formation mechanism was proposed. Also Cu2O was formed in the process. We found oxygen reduction reaction is a key factor to cause this phenomenon.