Influence of Field-Plate Configuration on Power Dissipation and Temperature Profiles in AlGaN/GaN on Silicon HEMTs

Thermal analysis of AlGaN/GaN high-electron mobility transistors on silicon has been performed with emphasis on the influence of the field-plate configuration on power dissipation and temperature profiles along a 2-D electron gas. The results highlight the importance of the field plates in power dissipation and show the difference between various field-plate configurations. Consequently, their design is important for a good thermal behavior and reliability of the transistors. By means of coupled technology computer aided design and finite element modeling simulations, a model is developed and used to characterize test structures in the saturation regime for power densities up to 12 W/mm. In addition, experiments are presented providing RF extraction of the ac output conductance and showing the influence of self-heating in a wide frequency range. In this way, the thermal resistance is extracted. The measured results are in good agreement with the electrothermal model.