关键词: 增强型GaN HEMT, ⁶⁰Co γ射线辐照, 直流特性测试, 退火测试

Abstract: Using ⁶⁰Co γ-rays to carry out total dose radiation test and room temperature annealing test on P-type gate enhancement GaN high electron mobility transistor (HEMT) under zero bias state, the response of DC characteristic parameters of GaN HEMT to total ionizing dose (TID) is investigated. The experimental results show that the threshold voltage, peak transconductance and saturation drain current of the device are degraded in different degrees after γ-ray irradiation, while the gate leakage current and conduction resistance change very little. At the dose of 0.6 Mrad (Si), after 120 h annealing tests, the threshold voltage of the device does not recover obviously, and the peak transconductance tends to degenerate slightly instead. From the experimental data, it can be seen that the degradation of the DC characteristics of the device is mainly due to the decrease of the concentration of two-dimensional electron gas (2DEG) caused by irradiation, the decrease of carrier mobility, and the induction of interfacial state traps. The results of the study give a useful reference for the evaluation of the reliability of GaN HEMT devices for aerospace applications.

Key words: enhancement GaN HEMT, ⁶⁰Co γ-ray irradiation, DC characteristic test, annealing test