Diamond power electronics : from device simulation to implementation in power converters
Résumé
In this talk, I will focus on the specificities of diamond power devices, from the simulation of Field Effect high voltage Transistors (FET) to the characterization and implementation of diamond devices in power converters. Indeed, diamond has unique electrical and thermal properties and dedicated simulation and characterization tools are required [1]. Moreover, to demonstrate the full potential of diamond in power electronics, high temperature operation above 200°C is required to reduce conduction losses and reach higher figure of merits [2-4]. However, typical electronics associated with diamond power devices will have eventually to work at such high temperatures, with high constraints on reliability. Possible solutions to guarantee low conduction losses and high switching speed with diamond power devices will be presented.
In this context, I will first present the recent research on simulation of diamond power devices, with a special focus on FET and drift region optimization (contribution of contact, access, channel and drift region resistance to the total ON state resistance). The transient dV/dt immunity of different FET architectures has been studied and will be presented, with design constraints above 200kV/µs to guarantee low switching losses. Model accuracy (avalanche breakdown, conduction mechanisms, impurity modelling) and convergence issues (2D and 3D structures, transient analysis, temperature dependence) will be discussed.
Finally, characterization and implementation of diamond power devices in a 100W power commutation cell will be described. A particular focus will be done on self-heating during measurements (DC, pulsed DC, large signal switching), dedicated high temperature - high speed gate drivers and optimized power commutation cell. New prospects such as monolithic integration for diamond power electronics will be briefly introduced. Although a lot of work is still remaining on the material side, it is indeed the right time to push forward the diamond power electronics.
The research leading to these results has been performed within the GreenDiamond project (http://www.greendiamond-project.eu/) and received funding from the European Community's Horizon 2020 Programme (H2020/2014-2020) under grant agreement n° 640947.