| abstract |
After a copper diffusion preventing film 4 is formed on a copper pad 1 , a barrier metal including a titanium film 5 , a nickel film 6 , and a palladium film 7 is formed on the copper diffusion preventing film 4 . The copper diffusion preventing film formed on the copper pad suppresses diffusion of copper. Even when a solder bump is formed on the copper pad, diffusion of tin in the solder and copper is suppressed. This prevents formation of an intermetallic compound between copper and tin, so no interface de-adhesion or delamination occurs and a highly reliable connection is obtained. This structure can be realized by a simple fabrication process unlike a method of forming a thick barrier metal by electroplating. In this invention, high shear strength can be ensured by connecting a solder bump, gold wire, or gold bump to a copper pad without increasing the number of fabrication steps. |