STUDY OF SLURRY CHEMISTRY IN CHEMICAL MECHANICAL POLISHING (CMP) OF COPPER

摘要

The chemical mechanical polishing of copper in several slurry chemistries based on KIO_3 oxidizer has been investigated. Benzotriazole (BTA), ethylenediamine tetraacetic acid (EDTA), and potassium iodide (KI) were used for preparing the polishing slurries. From the results of potentiodynamic polarization measurements, ICP-AES, XPS, and polishing rates, it was determined that BTA and KI are effective in forming passive layers in the pH range 4~8. Using EDTA enhanced the polishing rate due to increasing copper dissolution rate. In addition, we showed that the removal rate depends on the properties of surface passive layer and dissolution rate of abraded surface layer during CMP.