Technological approaches towards high voltage, fast switching GaN power transistors

摘要

Approaches towards fast switching GaN devices for applications in power electronics are discussed. First, an overview on the most prominent techniques towards increased breakdown voltage will be given for devices grown on SiC and Si substrates. These techniques will then be set in relation to dynamic switching properties at different bias voltage levels. Dynamic switching properties are still lagging behind competing devices, especially if switching at high bias levels is considered. The switching properties are usually expressed by the so-called dynamic on-state resistance. It significantly depends on technological parameters such as epitaxial layer design and crystalline quality of the buffer layer, passivation layers and, last but not least the lateral device designs (e.g. field plate arrangements). A balanced trade-off between all these influencing quantities is shown and correlated to current state of GaN high voltage switching devices.