Power components in wide bandgap materials
Introduction to power microelectronic devices

The development of alternative energy sources means that power grids need to be rethought in order to bring this energy from multiple sources to the customer, over long distances. With this in mind, HVDC networks are set to expand: power switches embedded in converters need to adapt to a new voltage range that can reach several tens of kV!

Silicon is therefore no longer viable: a drift zone doping of 10¹³ cm^-3 for an epitaxy thickness of 200 µm gives a resistivity of several Ω. Chip sizes are becoming large (several cm²) in order to maintain acceptable on-state resistances.

Wide bandgap materials, as their name suggests, have a wider bandgap than silicon, from approximately 3 to over 5 eV. The best-known of these are silicon carbide (SiC), present in various polytypes (3C and 4H), and gallium nitride (GaN). In fact, several component manufacturers (Wolfspeed,...