Performance of commercial foundry-level AlGaN/GaN HEMTs after hot electron stressing

• Hot electron or Channel Hot Carrier (CHC) degradation explored in AlGaN/GaN HEMTs.
• Hot electron stress test reported for commercial foundry-level AlGaN/GaN HEMTs.
• Devices stressed following prior literature methodology, then with Vd overstress.
• Hot electron stress revealed no hot electron degradation at expected conditions.
• Greater detail is revealed about devices, testing, and types of degradation observed.

The performance degradation of commercial foundry level GaN HEMTs placed under a constant-power drain voltage step-stress test has been studied. By utilizing electroluminescence measurement techniques to optimize hot electron stress testing conditions (Meneghini, 2012), no significant permanent changes in saturation current (Idss), transconductance (Gm), and threshold voltage (Vth) can be seen after stress testing of drain voltages from 30 V up to 200 V. We observe little permanent degradation due to hot electron effects in GaN HEMTs at these extreme operating conditions and it is inferred that other considerations, such as key dimensions in channel or peak electric field (Chynoweth, 1958; Zhang and Singh, 2001) [2,3], are more relevant to physics of failure than drain bias alone.