Failure analysis on recovering low resistive via in mixed-mode device

In this paper, it will be presented the FA flow used to localize and characterize a recovering resistive via on die business customer rejects on an analog automotive integrated circuit with a mature technology. Despite the use of advanced FA techniques and tools, both electrical and physical analyses were challenging due to the recovery failure and to the difficulty to quantify the subtle variation at metal1/metal2 interface between a fail and a reference via. Finally, a comparison of different FA techniques applicable to our case to localize with success a recovering resistive via without modifying the initial failure will be discussed.