Dynamic drift effects in GaN power transistors: Correlation to device technology and mission profile

GaN devices for high voltage power switching are facilitating smaller, more light-weighted and more efficient converter systems. In order to provide an optimum design of such systems it is necessary to understand dynamic GaN device performance in dependence on targeted mission profile and technological parameters. The paper shortly introduces to GaN device technology and provides a widely accepted physical interpretation of mechanisms that may adversely influence device switching properties. Then important scenarios of GaN power transistor switching are presented and correlated to biasing conditions relevant for in-system device operation. In detail, dynamic switching properties depending on off- and on-state time and voltage, substrate biasing conditions and temperature are analysed and correlated to different device technologies and manufacturers. The abovementioned parameters are influencing dynamic device properties in quite a complex manner and can often be considered as a characteristic finger print of a specific technological implementation or a specific device or epitaxial manufacturer.