Electroless Cu bottom-up filling using 3-N,N-Dimethylaminodithiocarbanmoyl-1-propanesulfonic acid (DPS)

Abstract

Cu bottom-up filling in Cu electroless deposition was attempted using 3-N,N-dimethylaminodithiocarbamoyl-1-propanesulfonic acid DPS . An accelerating effect on the planar surface was observed at low DPS concentrations, while a suppressing effect was found at higher concentrations. Co-addition of 2,2 -dipyridyl enhanced the surface morphology. Filling profiles were dependent on the concentration of DPS added, and Cu bottom-up filling was achieved due to a concentration gradient by diffusion of DPS between the top and bottom of the trench.