Barrier cap for under bump metal

摘要

A semiconductor wafer having solder bumps thereon for use in flip-chip bonded integrated circuits comprises a semiconductor substrate formed with metal bond pads at selected locations thereon, a metal electroplating buss layer or layers over the bond pads, a layer of solder-wettable under bump metal on the buss layer, a layer of barrier metal which overlies and encapsulates the solder-wettable metal, and a solder bump formed on the barrier metal.