This disclosure discusses cleaning of semiconductor wafers after the
Chemical-Mechanical Planarization (CMP) of the wafer during the
manufacturing of semiconductor devices. Disclosed is an acidic chemistry
for the post-CMP cleaning of wafers containing metal, particularly
copper, interconnects. Residual slurry particles, particularly copper or
other metal particles, are removed from the wafer surface without
significantly etching the metal, leaving deposits on the surface, or
imparting significant organic (such as carbon) contamination to the wafer
while also protecting the metal from oxidation and corrosion.
Additionally, at least one strong chelating agent is present to complex
metal ions in solution, facilitating the removal of metal from the
dielectric and preventing re-deposition onto the wafer. Using acidic
chemistry, it is possible to match the pH of the cleaning solution used
after CMP to that of the last slurry used on the wafer surface.