New method for measuring the different region thermal resistance of AlGaAs/GaAs HEMTs in a large temperature range

The thermal resistance of different region in the AlGaAs/GaAs HEMTs is measured in a large temperature range by the pulsed switching electrical method. The thermal resistance of the chip solders and base can be measured, respectively, through the cooling response curve processed by the structure method. As the temperature increases, the total thermal resistance increases by 50% from -20°C to 150°C. And the increase of chip thermal resistance is about 67.2% of the total increased thermal resistance. It can be attributed to the decrease of the chip heat conductivity and the enhancement of phonons collisions. The result is significant for the thermal design and the reliability design of HEMTs.