Breakdown and dynamic effects in GaN power switching devices

Approaches towards fast switching GaN devices for applications in power electronics are presented. First, an overview on breakdown mechanisms in GaN power devices is given. Suitable techniques towards devices with high breakdown strength are then discussed and set into relation to their specific dynamic switching properties. It has been found that dynamic switching properties of GaN power devices may be significantly compromised at high drain bias levels. The dynamic effects depend on technological parameters such as epitaxial layer design and crystalline quality of the buffer layer, passivation layers and the lateral device designs (e.g. field plate arrangements). GaN high voltage switching devices therefore require a balanced trade-off between all these influencing quantities. This paper concentrates on dependencies related to the epitaxial design of the buffer layer(s). (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)