The selection of chemicals in CMP slurry via electrochemical screening

Corrosion is an important issue during chemical mechanical polishing (CMP). The surface protection should be considered during CMP and also after CMP post cleaning step. There are several parameters have an impact on corrosion of metal surfaces during CMP such as chelating agent (AC), corrosion inhibitor (I) and pH. Electrochemical behavior of cobalt, copper and tantalum are investigated for different type of chelating agent, corrosion inhibitor at various concentrations. It is observed that the presence of a specific AC at low pH value shows the best corrosion protection on cobalt, copper and tantalum surface based on the same concentration conditions. Moreover, corrosion inhibition with I02 was obtained to be better than I01 on cobalt and tantalum, but I02 was worse on copper. The galvanic corrosion behavior between cobalt and copper to tantalum were also demonstrated in this article. AC1 and I02 chelating agent-corrosion inhibitor couple were found to have good performance of galvanic corrosion performance.