Extraction of an Electrothermal Mobility Model for AlGaN/GaN Heterostructures

An electron mobility model for AlGaN/GaN heterostructures taking both the lattice temperature and electric field into account is proposed. The numerical device simulation of an ungated Al0.25Ga0.75N/GaN HEMT structure on a 4H-SiC substrate is compared to measured electrical characteristics. Mobility model parameters are extracted by comparing isothermal numerical simulations with microwave (6 GHz) large-signal measurements. The extracted model was used in static simulations, showing good agreement with measurements.