Characterization of solderable metallization on power devices for 3-D packaging

This paper presents processing issues of solderable metallization on two different IGBTs (insulated gate bipolar transistors) for three-dimensional packaging. Identical metallization processes via sputtering have resulted in different contact resistances due to the different passivation materials (Si/sub 3/N/sub 4/ and polyimide) of the two devices. XPS and SEM characterization of surface compositions of device contact pads resulting in different electrical contact resistances are analyzed.