5 MeV质子辐照对增强型GaN HEMT器件的影响研究

Background] Gallium nitride power devices have been focused on anti-irradiation field due to its excellent performance. [Purpose] In order to explore the anti-proton irradiation damage ability of enhancement mode gallium nitride devices with different structures, [Methods] A 5 MeV proton irradiation experiment with irradiation fluence of 21012~11014 p/cm2 was carried out for the enhancement mode Cascode structure and P-GaN gate structure GaN HEMT devices manufactured by Transphorm and Innoscience, and the degradation rule and damage mechanism of the devices after proton irradiation were obtained. [Results] The experimental results show that under 5 MeV proton radiation, the threshold voltage of the enhancement mode Cascode device has a serious negative drift and the saturated drain current increases significantly with the increase of irradiation dose. When the irradiation dose reaches 11013 p/cm2, the characteristic degradation of the device tends to be stable. For P-GaN gate structure GaN HEMT devices, after 5 MeV proton radiation, the degradation law of the electrical characteristics of the devices is opposite to that of Cascode structure devices, and the degradation degree is significantly smaller than that of Cascode structure devices, indicating that enhancement mode Cascode structure devices are more sensitive to proton irradiation. The low frequency noise test shows that the variation of noise power spectrum density of the device after 5 MeV proton irradiation is consistent with the degradation of electrical characteristics. [Conclusions] It is concluded that the ionization damage effect induced by proton irradiation produces oxide trap charges and interfacial trap charges in the cascade Si MOSFET gate oxide layer of Cascode structure device, which is the main reason for its sensitivity to proton irradiation.