Effect of Organic Amine in Colloidal Silica Slurry on Polishing-rate Selectivity of Copper to Tantalum-nitride Film in Copper Chemical Mechanical Planarization

Abstract

We investigated the effect of organic additives with amine functional group such as alanine and polyacrylamide (PAM) on the copper chemical mechanical planarization. We found that addition of alanine can significantly increase the copper polishing rate while slightly decrease the TaN polishing rate. We also concluded that small amount addition of PAM drastically suppress the TaN polishing rate. Both alanine and PAM can enhance the Cu-to-TaN removal selectivity. Finally, we also explained the interaction between organic additives and Cu/TaN film through the zetapotential.

Influences of Organic Additive Molecular Weight in Colloidal-Silica-Based Slurry on Final Polishing Characteristics of Silicon Wafer

“…Chemical mechanical polishing (CMP) is widely applied during the manufacturing of semiconductor substrates and devices, for example, for polishing of silicon wafers, shallow trench isolation, the copper dual-damascene process for forming metal interconnects, and polycrystalline silicon polishing for forming floating gates in the NAND flash memory. [1][2][3][4] Especially, polishing of silicon wafer has been used for a long time and applied as a final step of the silicon wafer manufacturing procedure to reduce surface roughness and the number of particles remaining on the silicon-wafer surface. 1 Polishing of silicon wafer is conventionally applied in two separated steps: stock-removal polishing and final-touch polishing.…”