The effect of neutron irradiation on the AlGaN/GaN high electron mobility transistors

Abstract

AbstractThe SiN‐passivated AlGaN/GaN high electron mobility transistors were investigated by 1MeV neutron irradiation at fluences up to 1015 cm‐2, yielding a significant degradation for the transconductance near the knee voltage and the reverse gate leakage current at fluences ranging from 1014 to 1015 cm‐2 which could be attributed to the irradiation induced mobility shift and the defects in SiN passivation layers respectively since no any recovery was found after 20 hour annealing at room temperature. Meanwhile the negligible degradation of the saturation drain current, the maximal transconductance and the threshold voltage gave the fact that the effectiveness of SiN layers in passivated surface states in the source‐gate spacer and gate‐drain spacer was undiminished by neutron irradiation. Moreover the ohmic contact was robustness to neutron since the sheet resistance of ohmic contact region hardly shifted, but the schottky characteristics degraded obviously. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)