Physical failure analysis methods for wide band gap semiconductor devices

Wide band gap (WBG) materials are more and more used for high frequency and power electronic applications demanding standardized methods for reliability testing and failure analysis. Long term stability and degradation mechanisms are partly understood but compared to Si technology there are still many open questions. The knowledge about the physical properties in correlation to electrical behavior is essential to design appropriate standardized performance and reliability tests. This paper summarizes relevant failure analysis methods to locate electrical defects and analyze related structures in WBG devices with specific focus on HEMT technologies. Two examples for the identification of physical failure modes at metal semiconductor interfaces are discussed. In the last chapter efficient workflows for the physical failure analysis are suggested.