Abstract:

In order to study the influence of drain bias on the reliability of P-GaN devices, the drain stress tests of P-GaN commercial devices is conducted. By changing the drain stress bias voltage and bias time, the on resistance and threshold voltage of GaN device are observed and recorded. The test results show that the on resistance of devices without P-GaN drain structure increases first and then decreases with the change of drain voltage, while the threshold voltage is almost unaffected. The on resistance of devices with P-GaN drain structure is almost unaffected, while the threshold voltage decreases first and then increases with the change of drain voltage. In addition, through the test of different pressurization time, it is found that with the increase of time, the device without P-GaN drain structure has obvious degradation, and the device with P-GaN drain structure has relatively stable performance. The reliability of commercial GaN devices with different structures is affected by the change of drain bias conditions,and the appropriate devices should be selected according to the application conditions.

Key words: P-GaN device, reliability, on-resistance, threshold voltage, off time, drain voltage, surface trap