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 beta -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.