PhD
Process Technology
Power devices
III-Nitride semiconductors have emerged as important materials for high temperature and high power electronic devices needed e.g. for automobile engines, future advanced power distribution systems, all electric vehicles and avionics.
In the search towards cleaner and durable energies, high efficiency power switching devices are highly demanded for power conversion. Typical examples include hybrid cars, distributed power grids for renewable energies, and more generally drive electronics for power supply. Existing power electronics, based on Si, have reached theoretical limits of the material, regarding high voltage and high speed operation. The only breakthrough can arise from a change of the material itself. Thanks to its wide band gap of up to 6.2eV and associated outstanding electrical transport and breakdown properties, InAlGaN is nowadays the best candidate for high power high speed switching devices. This is reflected in lower conduction and switching losses leading to more efficient circuit operation. III-nitrides are also able to withstand very high temperature conditions, such as required in motor applications. For certain applications, the intrinsic depletion mode operation of GaN high electron mobility transistors (HEMT) is not suitable, so that new transistor configurations are required to obtain a normally-off device. The technology should also be able to integrate transistors and diodes in the same process. The development of these high performance switching devices for power conversion with GaN technology is the topic of this PhD.
Part of the study will focus on the improvement of e-mode transistors integrated with diodes, as well of optimization of the device design towards higher breakdown field (field plate technique) and high operating temperature.
Responsible scientists:Marianne Germain, Staf Borghs