Break through developments in electroless nickel/gold plating on copper based semiconductors

The transition from aluminum based, to copper based integrated circuits will enable another generation of faster and smaller integrated circuits. As the technology moves out of the lab and enters mainstream fabrication, the infrastructure necessary to support Cu will take front stage. The initial focus will be on capital equipment and process optimization. Close behind will be product testability and field reliability concerns. Electroless nickel coupled with immersion gold provides a stable, versatile surface on top of copper. This surface enables the subsequent use of several different types of interconnect methods to the I/O pads. Oxide free pads allow for more accurate, less damaging probe testing. Electroless Ni/immersion Au has already found successful field applications as a robust wire bond surface and enhanced corrosion protection for conductive epoxy applications. Testing is currently underway for solder based flip chip applications and suitability as a structure for TAB connections is also being investigated.