Alkaline barrier slurry applied in TSV chemical mechanical planarization

We have proposed a TSV (through-silicon-via) alkaline barrier slurry without any inhibitors for barrier CMP (chemical mechanical planarization) and investigated its CMP performance. The characteristics of removal rate and selectivity of Ti/SiO2 /Cu were investigated under the same process conditions. The results obtained from 6.2 mm copper, titanium and silica show that copper has a low removal rate during barrier CMP by using this slurry, and Ti and SiO2 have high removal rate selectivity to Cu. Thus it may be helpful to modify the dishing. The TSV wafer results reveal that the alkaline barrier slurry has an obvious effect on surface topography correction, and can be applied in TSV barrier CMP.