Physics Department Graduate Seminar
Friday, February 22, 2013
Time: 3:30 PM
Location: B.H. Snell 177
Graduate Speaker: Michael Turk
will speak on;
Electrochemical Investigation of Slurry Chemistry for Controlling Galvanic Corrosion during Chemical Mechanical Planarization of Ruthenium
Chemical mechanical planarization (CMP) of Ru barrier lines is expected to become a critical processing step in the fabrication of the new interconnect-structures. However, due to its novel metal characteristics, Ru induces galvanic corrosion in its adjacent Cu lines in the wet CMP environment, and resists chemical surface modifications that are necessary to support CMP. The present work reports a percarbonate based slurry formulation to address these challenges of Ru-CMP, and explores the considerations for residual Cu removal using the same slurry. With this slurry, wafer polish rates of about 10 and 80 nm/min are measured for Ru and Cu, respectively, resulting in defect-free processed samples. Electrochemical measurements of open circuit potentials and potentiodynamic polarization are performed to investigate the detailed surface reactions of Ru and Cu that facilitate material removal and control corrosion during the CMP of these metals.