The Use of Organic Additives to Stabilize and Enhance the Deposition Rate of Electroless Copper Plating

Abstract

A persistent problem in the use of electroless copper baths has been their tendency to decompose spontaneously. Materials previously proposed as stabilizers have, in general, the undesirable effect of decreasing the plating rate of the bath. It has been found in the present work that the organic additive 8‐hydroxy‐7‐iodo‐5‐quinoline sulfonic acid (HIQSA) not only stabilizes electroless copper baths but also enhances the plating rate by as much as 50%. The additive 2‐iodo‐3‐pyridinol stabilizes the solutions but has little effect on the plating rates. An explanation for this behavior is set forth and is supported by the stabilizing effect, if any, of other organic additives with structures similar to HIQSA.