Kinetics and mechanism of electroless deposition of copper in a bath of low copper and high formaldehyde concentrations

Abstract

The present paper attempts to examine the kinetics and mechanism of electroless copper deposition process at low copper ion and high formaldehyde concentrations. Both potentiostatic as well as steady state two compartment galvanic cell studies are employed to plot individual half cell reactions involved in the process. Actual deposition rates are also measured through gravimetrically determined weight gain. The observations indicate that the mixed potential, Em, lies on the anodic Tafel and cathodic limiting current regions, quite close to E-HCHO. Hence, the process at this condition is under cathodic diffusion control. It is possible to derive expressions for E-m and i(m) theoretically to match the experimental results.