Challenges and Solutions in Preparation for High Resolution Failure Analysis of Power Electronics

Abstract

The high-resolution failure analysis of power electronic devices is very challenging, as relatively large features have to be accessed and analyzed with nanometer resolution. Recently new tools have been introduced for fast and efficient sample preparation of stacked devices and complex packages. One of them is the focused ion beam (FIB) technique using a high energy Xenon Plasma-FIB. This paper outlines preparation issues needed to find the physics of failure of large and complex devices as used in power electronics. Different methods like high throughput Plasma FIB preparation to combined Laser-FIB preparation are compared. Additionally an innovative mechanical preparation technique developed for interface defect preparation of power electronic materials will be introduced. Within the paper selected case studies regarding reliability investigations and failure analysis are presented for example on silver sinter layers and bond wire contacts done by high resolution Transmission Electron Microscopy (TEM). In addition, an assessment of the analysis throughput increase, of new extended application ranges and current limitations will be given.