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The electrical degradation in AlGaN/GaN high-electron-mobility transistors (HEMTs) is examined under irradiation with 7.6-MeV carbon (C), 20-MeV oxygen (O), and 30-MeV fluorine (F) ions in situ. To characterize the radiation damage in the HEMTs, the ionizing dose Di, displacement dose Dd, and number of vacancies versus the chip depth in the devices have been calculated for heavy ions. As expected, in all three types of HEMTs, the output current decreases more than 30% and threshold voltage positive shifts after the irradiation fluence of 4 × 1012 ions/cm2. The performance degradation of AlGaN/GaN HEMTs is caused by radiation-induced charged defects. Based on calculation and experimental results, it is shown that the nonionizing energy loss (NIEL) method is not suitable for estimating the degradation of AlGaN/GaN HEMTs either considering gallium vacancy or considering both gallium vacancy and nitrogen vacancy. In the same displacement damage dose, the threshold voltage degradation rate depends on the type of incident particles and independent of the channel length. The damage caused by carbon ions is the smallest and the damage caused by fluoride ions is the largest. [ABSTRACT FROM AUTHOR]

Characteristics of displacement defects in the 3CK3637 PNP bipolar junction transistors (BJTs) irradiated by 10 MeV Si, 40 MeV Si and 25 MeV C ions are investigated in this paper. Electrical parameters are measured in-situ using KEITHLEY a 4200-SCS semiconductor characterization system during irradiations. The radiation-induced defects caused by various ions for different displacement damage doses are characterized by deep level transient spectroscopy (DLTS). Experimental results show that the electrical degradation increases with increasing irradiation fluence. It is worth noting that the increase trend of the electrical degradation is different for the three types of ions. For the 10 MeV Si ions, the electrical degradation linearly increases, while, for the 40 MeV Si and 25 MeV C ions, the electrical degradation increases nonlinearly. The change in the reciprocal of current gain (Δ(1/β)) caused by 40 MeV Si and 25 MeV C ions can be normalized in one line at lower displacement damage doses. As the displacement damage dose increases to a certain threshold, the Δ(1/β) deviates from the normalized line. Based on the DLTS analyses, the dominant displacement defects in the 3CK3637 PNP BJTs irradiated by 40 MeV Si and 25 MeV C ions change with increasing displacement dose, leading to the existence of threshold in the electrical degradation curve. [ABSTRACT FROM AUTHOR]