Effect of Complex Agent on Copper Dissolution in Alkaline Slurry for Chemical Mechanical Planarization

With the microelectronic technology node moves down to 45 nm and beyond, and to reduce the RC delay time, low-k dielectric materials have been used to replace regular dielectric materials. Therefore, the down force of chemical mechanical planarization (CMP) needs to decrease based on the characteristics of low-k materials: low mechanical strength. In this study, the effect of new complex agent on copper dissolution in alkaline slurry for CMP was investigated. Based on the reaction mechanism analysis of Cu in alkaline slurry in CMP, the performance of Cu removal rate and surface roughness condition were discussed. It has been confirmed that Cul slurry demonstrates a relatively high removal rate with low down force. And also, by utilizing the Cul slurry, good result of Cu surface roughness were obtained.