Degration Behavior and Mechanism Analysis of AlGaN/GaN HEMTs After RF Overdrive Stress

This work mainly observes the degradation behavior and analyses mechanism of AlGaN/GaN HEMTs under RF (Radio Frequency) overdrive stress. According to experiment results, after long-term RF stress of up to 650 hours, DC characteristics emerged degradation phenomenon. For example, the decrease of output drain current was up to 180 mA, threshold voltage had a positive drift of 0.23V and gate leakage current decreased one orders of magnitude. Gate-Lag and low frequency noise testing revealed an increase in defect in the device, and these traps capture electrons, which leads to more depletion of two dimensional electron gas (2DEG) in the channel. The increase in trap density can be explained by the hot electron effect under RF stress. The experimental results can provide reference for the reliability study of AlGaN/GaN HEMTs.