RF Extraction of Thermal Resistance for GaN HEMTs on Silicon

In this article, an ac conductance method has been successfully employed to extract the thermal resistance of GaN-based high-electron-mobility transistors (HEMTs) on silicon. The resulting resistances, when varying channel length and gate width, are comparable those obtained with pulsed measurements, by making use positive drain-to-source voltages from a zero power dissipation quiescent bias point 3-D simulations. Furthermore, geometry dependence HEMTs modeled for circuit-design purposes.