Formation of Nanoporous Copper-Silicide Films

Abstract

The possibility of forming nanoporous copper-silicide films with different phase compositions is experimentally demonstrated. For this purpose, the parameters of the initial a-Si/Cu structure and the conditions of its annealing are chosen so that the process of solid-phase synthesis comes to a halt at the stage of formation of a branched silicide cluster. Then the films are subjected to liquid etching in a mixture of diluted inorganic acids. In this case, the metastable Cu_xSi phase with a low Cu content is selectively removed, and a three-dimensional silicide cluster is released. At the same time, surface Kirkendall voids present in the films open. As a result of these two processes in combination, a nanoporous structure is formed.