Improvement of Ruthenium Polishing Rate by Addition of Guanidinium Ions

Inhalt:
Abstract: With the development of integrated circuits (IC), ruthenium (Ru) has been selected as one of the most promising barrier metals for copper interconnects to replace traditional Ta/TaN bilayer.The present work investigates certain chemical aspects of this strategy of Ru-CMP by using guanidiniumions (Gnd+). And the experiments are designed to study Ru CMP in pH 9 using colloidal silica-abrasive based slurry with an oxidizer (H2O2), Gnd+Ζ potential and electrochemical are employed to probe the surface effects that facilitate material removal in chemically prevailing CMP of Ru. The results of CMP show that Gnd+ are better than that of potassium ions (K+) on the removal rate (RR) of Ru under the same conditions; and the improvement of Ru RR has a guiding significance for the development of next generation IC in the addition of Gnd+, which is proven by ζ potential increasing. Key words: ruthenium; guanidiniumions; potassium ions; alkaline; CMP