Stability of GaN150-based HEMT in high temperature up to 400°C

The first high-temperature characterization of GaN150 HEMT devices is presented from ambient temperature to 400°C. With a 2-gate length of 150nm, three configurations of GaN150 are investigated. They have gate widths of 40µm (T 1 ), 100µm (T 2 ) and 200µm (T 3 ) respectively. The stability with temperature of the electrical characteristics of the AlGaN/GaN devices are measured with tungsten probes while the tested die is heated by a hot plate. The packaging is a standard tungsten based metallization, with Ni and Au plating, supporting a 92% alumina ceramic substrate. The drain saturation current decreases from 50mA, 150mA and 290mA at room temperature (RT) to 35mA, 110mA and 175mA at 400°C for T 1 , T 2 and T 3 respectively. The peak transconductance value of T 1 is dropped from 22mS at ambient temperature to 8mS at 250°C. The pinch-off voltage is stable at VGS = −5V during the whole temperature change.