Analysis of Electrical Performance Degradation of 4H-SiC Junction Barrier Schottky Diodes Induced by Neutron Irradiation

This study investigates the underlying mechanisms of electrical performance degradation in 4H-SiC junction barrier Schottky (JBS) diodes under 1 MeV neutron irradiation at varying fluence levels through both experimental measurements and Technology Computer-Aided Design (TCAD) simulations. Defects introduced by irradiation were characterized using Deep Level Transient Spectroscopy (DLTS) and Photoluminescence (PL). The experimental results show that neutron irradiation leads to an increase in forward series resistance and reverse leakage current, with the degradation becoming more pronounced as the neutron fluence increases from 1×1013n/cm2to 1 × 1014n/cm2. Notably, the degradation of reverse breakdown voltage is ascribed to a reduction in the Schottky barrier height caused by the increased defect concentration after irradiation. Simulations were employed to quantitatively elucidate the correlation between the degradation of electrical characteristics and key parameters including the Schottky barrier height, as well as the concentration and type of radiation-induced traps. The results of simulation, DLTS, and PL collectively indicate that the defects introduced by irradiation are the primary cause of the degradation in electrical performance. The concentration of Z1/2defects increased by about 7 times by DLTS when the neutron irradiation dose was increased from 1×1013n/cm2to 1×1014n/cm2. Moreover, deep-level acceptor traps induce more severe electrical degradation compared to shallow-level traps. This work establishes a solid theoretical foundation for investigating the impact of neutron irradiation on SiC power device reliability, offering guidance for future experiments and resource allocation.