Characterization and modeling of memory effects in switched GaN HEMT devices

• Applicants: Professor Dr.-Ing. Ingmar Kallfass; Professor Dr.-Ing. Matthias Rudolph
• Subject Area: Electronic Semiconductors, Components and Circuits, Integrated Systems, Sensor Technology, Theoretical Electrical Engineering
• Term: from 2020 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 440549658

GaN-based transistors are increasingly used in power and microwave electronics, since this material system can operate at higher voltages and currents and achieve shorter switching times than commercial transistors in other material systems. What is new is that GaN HEMTs for these very different tasks have a conceptually identical structure, so that they should be described in the circuit design also by a uniform model. At the same time, the operating modes converge when the switching operations in switching converters have to be calculated with the same high accuracy as in analog circuits, and when analog microwave power amplifiers increasingly use the transistor as a switch. This development calls for a new, uniform approach to transistor modeling. The memory effects typical for GaN HEMTs pose a particular difficulty, as they significantly worsen the efficiency of switching converters and amplifiers.On the basis of solid preliminary work in the field of modelling microwave and power transistors for circuit design and physical simulation, this project aims to develop a uniform GaN HEMT model for the simulation of switched amplifiers, which can explain the influence of trapping effects on switching behavior based on physics.

• DFG Programme: Research Grants
• International Connection: Israel
• International Co-Applicant: Professor Dan Ritter, Ph.D.