Abstract: A semiconductor device (10) includes a solder bump (40) that is formed using a gold-free under-bump metallurgy (UBM) (21). In a preferred embodiment, UBM (21) includes a diffusion barrier layer (22) of chromium and a metallic layer (24) of copper. The bump layer metallurgy (31) is deposited directly on the metallic layer, without an intervening gold layer. To overcome problems associated with a native oxide layer (26) which forms on the metallic layer, especially on copper, the bump metallurgy includes a seed layer (32) of tin that is deposited prior to a bulk lead layer (34). The bump metallurgy includes a final metallic layer (36) having sufficient tin to make a bump having approximately 97% Pb and 3% tin.

Abstract: The present invention includes a process for forming an electrical device. In one embodiment, the process includes applying a solid patternable film over a substrate and forming a conductive material over the substrate while the solid patternable film overlies the substrate, wherein the conductive material extends at least partially within an opening in the patternable film. In another embodiment, the process includes applying a patterned film over a substrate having a pad and exposing the patterned film and the substrate to energy. The patterned film includes a first region that includes a conductor and a second region that does not have a conductor. The energy of the exposure forms an electrical connection between the conductor and the pad.