This is a study of the effects of direct interactions between free radicals and metals. It is designed to test a hypothesis on the mechanism of etching of metal foils and thin films formulated to account for the results of previous work. Methylene radicals, produced by ultraviolet photodecomposition of diazomethane or ketene are studied first, followed by other radicals including methyl and oxygen atoms. The occurrence of etching in various oxidation systems, including those for ethylene, hydrogen, ammonia, and propane, is being investigated over a variety of metals including platinum, platinum alloys, palladium, and silver. The results of these studies will then be applied to catalyst redispersion and selective etching of thin films for integrated circuits.
