Structure and method for bond pads of copper-metallized intergrated circuits

摘要

A robust, reliable and low-cost metal structure and process enabling electrical wire/ribbon connections to the interconnecting copper metallization of integrated circuits. The structure comprises a layer of first barrier metal, deposited on the non-oxidized copper surface, having a copper diffusion coefficient of less than 1 x 10E-23 cm<2>/s at 250 DEG C and a thickness from about 0.5 to 1.5 mu m. It further comprises a layer of second barrier metal on the layer of first barrier metal, having a diffusion coefficient of the first barrier metal of less than 1 x 10E-14 cm<2>/s at 250 DEG C and a thickness of less than 1.5 mu m. It finally comprises an outermost layer of bondable metal, onto which a metal wire is bonded for metallurgical connection. The first barrier metal is selected from a group consisting of nickel, cobalt, chromium, molybdenum, titanium, tungsten, and alloys thereof. The second barrier metal is selected from a group consisting of palladium, cobalt, platinum and osmium. The outermost metal layer is selected from a group consisting of gold, platinum, and silver.