Physical Mechanism of Device Degradation & its Recovery Dynamics of p-GaN Gate HEMTs Under Repetitive Short Circuit Stress

In this work, the short circuit (SC) ruggedness of Schottky type p-GaN gate high electron mobility transitions (HEMTs) was studied by repetitive SC stress. The prominent threshold voltage (V
TH
) shift up to +0.77 V and drain current (I
D
) reduction were observed with the increase of the repetitive SC cycles. Besides, the device recovery dynamics were recorded after SC stress. The degraded characteristics (e.g. V
TH
and I
D
) exhibit a complete recovery after lenient SC stress due to the release of the trapped electrons in the gate region. On the contrary, under stringent SC stress, hot electron induced defects and electron trapping are respectively generated in the gate region and access region close to drain electrode, which results in irreversible V
TH
shift and I
D
reduction.