Constriction-Induced Local Electrodeposition The Principle of Self-Induced Repair

Abstract

A fundamental study of the self-induced repair (SIR) of constrictions is presented. SIR is a local electrodeposition process induced by the Joule heating at a constriction, together with the temperature dependence of the equilibrium potential at a metal-electrolyte interface. Based on a one-dimensional heat-conduction model, a general equation for the maximum temperature rise at a constriction is obtained. An analysis based on thermodynamics and a series of experiments show a substantial temperature dependence of the equilibrium electrode potential of the Cu/Cu2+ interface. The rate of electrodeposition is then estimated using the Butler-Volmer equation. The evolution of constrictions during the SIR process is studied with numerical simulation. It is predicted that with a local temperature rise of 50 K, the deposition rate can be as high as 2| μm per min, which is verified by a series of experiments. The results of theory and experiment show that the SIR process is self-locating and self-terminating. Electrical testing shows that the SIR process is able to eliminate the electrical symptoms of the constrictions completely. Scanning electron microscopy study shows that the electrodeposited copper has a dense and continuous texture. The use of the SIR process for repairing complete opens and making customized interconnections is also discussed. © 1991, The Electrochemical Society, Inc. All rights reserved.