A recent study explores how optimization of field plates and doping profiles can mitigate the effects of charge traps in p-GaN-based HEMT transistors. These devices, promising for power and high-frequency applications, suffer performance degradation attributed to electron capture in trap states, which cause leakage currents and dispersion in output characteristics.

GaN HEMTs are key candidates for high-efficiency power electronics, but the presence of traps in the heterostructure limits their reliability. Previous work has addressed this problem through surface passivation and field structure design, but the interaction between the channel doping profile and field plate geometry had not been explored systematically.

The team uses TCAD simulations to model the electric field distribution and trap occupancy as a function of field plate geometry and dopant concentration. This approach makes it possible to identify configurations that reduce the maximum field in critical regions, thereby decreasing carrier injection into the traps.

The results show that a suitable combination of field plates and optimized doping significantly reduces leakage current and dispersion in output characteristics, bringing device performance closer to the theoretical limit without traps. The authors note that these design strategies could be applied to other nitride-based heterostructures.

The study opens the door to more reliable GaN devices for power converters and radiofrequency amplifiers. Future research could validate these results through experimental measurements on devices fabricated with the proposed geometries.