A novel TSV (Through Silicon Via) Silicon backside polishing slurry has been developed to offer the solution to integration flexibility of TSV applications. The requirements for back-side silicon substrate polishing are to deliver fast silicon removal rate for high throughput, tunable Cu/Si selectivity to achieve desired final topography. Owing to different oxidation properties between silicon substrate and copper metal, it is challenging to achieve both high copper and silicon removal rates with the conventional oxidize, like hydrogen peroxide which also suffers from short slurry pot life. In this study, we investigated a non-peroxide oxidizer, instead of hydrogen peroxide, which can effectively oxidize both silicon and copper metal and to give the relative higher Si and Cu removal rates higher than 0.8μm/min @ 3psi down force, and benefit longer pot life. The Si/Cu selectivity can be fine tuned from 1.6 to 1 as increasing oxidizer concentration from 0.3 to 0.8 wt.%