Abstract
The fabrication of semiconductor devices is handling, processing and test verification intensive all of which present opportunities for electrical over stress (EOS) or electro static discharge (ESD) to occur. Well-documented models for ESD exist. These include Human Body Model (HBM), Machine Model (MM) and Charged Body Model (CBM), but such is not the case for EOS and its manifestations. In addition, as device technologies change and reduce in dimension these geometric reductions create increases in operating currents and magnetic fields located on the die surface. When there are occasions where devices are overstressed electrically in new device technologies, the manifestation or evidence of the EOS maintains the same appearance while physical dimensions have become much reduced. On occasions, the manifestation or evidence of EOS in some new device technologies tends to appear different from anything we have seen in past device technologies. The resolution of these new failure modes is not trivial to analyze. This case study will detail the diagnostic journey used to resolve one such new and unique failure, the “Star Crack”.