System and method of selectively cleaning copper substrate surfaces, in-situ, to remove copper oxides

摘要

A system and method are provided for selectively etching metal, preferably copper surfaces free of oxides in preparation for the deposition of an interconnecting metallic material. Metal oxides are removed with β-diketones, preferably Hhfac. The Hhfac is delivered into the system in vapor form, and reacts almost exclusively with copper oxides. The by-products are also volatile for removal from the system under reduced pressure. The procedure is easily adaptable to most IC process systems, it can be conducted in an oxygen-free environment, without the removal of the IC from the process chamber. The in situ cleaning permits a minimum amount of copper oxide to reform before the deposition of the overlying metal, permitting formation of a highly conductive electrical interconnection.