Electroless Co-B-P-W Deposition Using DMAB as Reducing Agent

Co-B-P-W alloy films were deposited by the electroless plating method on Cu foil and on Si wafer with a sputtered PVD TaN/Ta barrier and Cu seed substrate. The effects of concentration of the reactants and temperature on the deposition rate were investigated. By variation of electroless plating solution composition, Co-B-P-W coatings containing different amounts of boron, phosphorus and tungsten can be obtained under slightly acid conditions. Using operating conditions selected Co-B-P-W coatings containing 0.5-10.0 at. % W, 0.5-16.0 at. % B and 1.5-6.0 at. % P can be obtained. The induction period depends on solution composition, but can be effectively shortened by elevation of the temperature of working solution.