Leakage current of 1200 V 4H-SiC Schottky Barrier diodes (SBDs) with different structures increased by various degrees after heavy-ion exposure. By taking I-V measurements in a range of 298 to 448 K, the voltage dependence of saturation current (I0), barrier height (ϕB0), and ideality factor (n) were obtained. The dependence of these parameters with temperature illustrates the Gaussian distribution of barrier height. The inhomogeneity of the Schottky barrier height distribution was successfully described using a modified thermionic emission model with Gaussian distribution, and the average barrier height (¯ϕB0) was gained. The results show that the barrier height distribution of all SBDs remain unchanged after the irradiation which means heavy-ion exposure did not affect the Schottky barrier.

The defects and electrical characteristics of 4H-SiC JBS diodes irradiated by 2 MeV protons under irradiation temperatures of 100–400 K were studied. Forward and reverse current–voltage (I–V), capacitance–voltage (C–V), and deep-level transient spectroscopy (DLTS) measurements were performed to study the changes in the characteristics of the device before and after variable-temperature proton irradiation. As the irradiation temperature increased from 100 to 400 K, the on-resistance decreased from 251 to 204 mΩ, and the carrier concentration gradually increased. The reverse current–voltage experiment results showed that the leakage current increased after proton irradiation at each irradiation temperature compared to before irradiation. The DLTS spectra analyses showed that proton irradiation mainly introduced a carbon vacancy related to the Z1/2 center (E_0.68 and E_0.72), which may have been the main reason for the changes in the forward and reverse electrical characteristics. The intensity of the DLTS spectrum decreased with the increasing irradiation temperature, indicating that the concentration of defects gradually decreased, due to the increase in the radius of the recombination of a vacancy with a related interstitial atom.

The heavy ion radiation response and degradation of SiC junction barrier Schottky (JBS) diodes with different P+ implantation intervals (S) are studied in detail. The experimental results show that the larger the S, the faster the reverse leakage current increases, and the more serious the degradation after the experiment. TCAD simulation shows that the electric field of sensitive points directly affects the degradation rate of devices with different structures. The large transient energy introduced by the heavy ion impact can induce a local temperature increase in the device resulting in lattice damage and the introduction of defects. The reverse leakage current of the degraded device is the same at low voltage as before the experiment, and is gradually dominated by space-charge-limited-conduction (SCLC) as the voltage rises, finally showing ballistic transport characteristics at high voltage.

At present, the single-pulse unclamped inductive switching (UIS) characteristics of SiC MOSFET have been fully studied. The current mainstream research suggests that the failure mechanism of MOSFET under a single UIS shock is divided into parasitic BJT conduction and metallization failure. However, there are still some shortcomings in the current research. First, it is difficult to distinguish these two failure mechanisms. Second, it is difficult to propose feasible optimization schemes. Therefore, it is still necessary to further explore the mechanism of single-pulse UIS. In this study, Sentaurus TCAD software was used to simulate different P-base doped MOSFETs, and the effect of doping concentration and morphology of the P-base region on the single-pulse UIS failure mechanism was revealed. By designing the P-base region, the BJT conduction failure and metallization failure can be distinguished. In addition, the study also proved the relationship between breakdown voltage and the maximum temperature (T _max) in the UIS process, and on this basis, an optimization scheme for the single UIS characteristics of MOSFET was proposed.