Aqueous fluoride residue removers for 32 nm and beyond copper ultra low-K technologies

Mallinckrodt Baker, Inc. (MBI) has developed an aqueous fluoride-based cleaner (AFC1) that shows improved ultra-low k (ULK) and cobalt tungsten phosphide (CoWP) compatibility over dilute hydrofluoric acid (dHF) and a simple solvent based cleaner (SFC1). Performance and compatibility testing was performed with beaker tests at MBI and on 45 nm wafers by GLOBALFOUNDRIES. Our results indicate that AFC1 may be a good alternative to dHF for future Cu technologies.