Impedance Study of the Electroless Copper Films

Abstract

The formation of atomic or molecular hydrogen is inevitable due to the oxidation of reducing agents in electroless deposition.The highly mobile atomic hydrogen within the electroless copper layer possibly combines to form voids, which may alter the hydrogen diffusion path.An interstitial diffusion mode, adopted to resolve the movement of atomic hydrogen, resulted in two segments in the Arrhenius plot.It was estimated that the diffusivities of atomic hydrogen in the electroless copper films were D1 = 3.4 10 -2 exp [-7500/T] in the range of 283-308 K, and D2 = 8.5 10 -7 exp [-5000/T] in the range of 308-343 K.The threshold temperature for electroless copper to be nucleated on the platinum electrode was estimated at 318 K, correlating to the phase angle drift derived from the fixed frequency impedance technique.