In this article, the single event burnout (SEB) performances for 2DEG Al _x $\text{Ga}_{{1}-{x}}\text{N}$ channel p-GaN gate high electron mobility transistors (HEMTs) have been investigated comprehensively to reveal the failure mechanisms and broaden applications in harsh environments. As Al composition ${x}$ increases from 0.0 to 0.4, ${V}_{\text {BR}}$ increases from 500 to 730 V, and the corresponding SEB voltage ${V}_{\text {SEB}}$ at linear energy transfer (LET) = 10 pC/ $\mu \text{m}$ increases from 300 to 450 V. Possible mechanisms of Al _x $\text{Ga}_{{1}-{x}}\text{N}$ channel HEMTs from the perspective of electric field ( ${E}$ -field) are proposed. ${E}$ -field near source and drain side after radiation would have a high peak ${E}$ -field and that of p-GaN layer exceeds 3.3 MV/cm of critical ${E}$ -field for GaN material, causing SEB to occur (LET = 10 pC/ $\mu \text{m}$ ). When SEB occurs in HEMTs, ${E}$ -field would increase rapidly and cannot be recovered. A new phenomenon has been first discovered when SEB occurs in Al _x $\text{Ga}_{{1}-{x}}\text{N}$ channel HEMTs with p-GaN gate ( ${x} = {0.0}$ –0.4, step = 0.1). In addition to the back-channel effect, an excess of holes would be left in the buffer layer after electrons flow toward the drain. It allows the injection of an excess of holes in the buffer layer into the gate with low potential, resulting in a sharp increase in ${I}_{\text {G}}$ . Simulation results indicate that AlGaN channel HEMTs have great advantages in SEB performances compared with the traditional GaN channel HEMTs.

Breakdown voltage (BV) shifting behavior induced by total-ionizing-dose (TID) irradiation is investigated for high-voltage SOI LDMOS, in this letter. The BV increase caused by irradiation is present for the first time, and the degradation mechanism is revealed by modeling and simulation. Irradiation-induced electric field modulation exerts an impact on the competition between the lateral BV and vertical BV and results in BV shifting. The dielectric field is enhanced by irradiation-induced positive oxide trapped charges in the BOX layer, which is responsible for the BV increasing after irradiation. A TID radiation hardening approach is proposed so that the lateral BV is required to be properly higher than vertical BV instead of pursuing equality.

In this article, we proposed a comprehensive model for predicting the degradation of SiC MOSFETs after gamma-ray irradiation. It is experimentally founded that SiC MOSFETs exhibit different degradation behaviors under gate bias (i.e., ${V}_{\text {GS}} =15$ V and ${V}_{\text {DS}} $ = 0 V) and drain bias (i.e., ${V}_{\text {GS}} $ = 0 V and ${V}_{\text {DS}} =400$ V) in terms of threshold voltage ( ${V}_{\text {TH}}$ ) and ON-resistance ( ${R}_{\text {ds}, \text{ON}}$ ). TCAD simulation shows that gate bias causes a high electric field in gate oxide above the MOS channel region, while drain bias generates relatively lower electric field in gate oxide around near-channel region. The differences in electric field under gate bias and drain bias lead to different hole yields and charge accumulation in gate oxide, which is the underlying physical mechanism for their different degradation behaviors. ${V}_{\text {TH}}$ is chosen as the parameter to quantify the accumulated charges in gate oxide and further predict irradiation-induced degradation. The relationship between the variation of threshold voltage ( ${\Delta} {V}_{\text {TH}}$ ) and the total ionizing doses (TIDs) under both gate and drain bias is formulated and validated. Comparison among measured data, TCAD simulation, and model prediction shows that the maximum prediction error is lower than 0.08 V, which proves the rationale and accuracy of the proposed degradation model. In addition, the two submodels for gate bias and drain bias are unified as one according to the time dependence effect (TDE) for TID irradiation. The proposed model could be useful to predict the degradation and/or lifetime of SiC MOSFETs in irradiation environments.

The breakdown voltage (BVDS) variation of 400V silicon-on-insulator (SOI) n-channel laterally diffused metal oxide semiconductor field effect transistors (NLDMOSFETs) is examined after exposure to total ionizing dose (TID). The results for OFF bias and ON bias are explored. For OFF bias, the BVDS increases first and then degrades with accumulated dose. For ON bias, the irradiated device shows soft breakdown after irradiation. The physical mechanisms for these variations are analyzed and confirmed by technology computer aided design (TCAD) simulation.

Recently, Shu et al. published “Numerical and Experimental Investigation of TID Radiation Effect on the Breakdown Voltage of 400 V SOI NLDMOS.” This short article is an extension of that earlier article. The breakdown voltage of 400-V silicon-on-insulator n-channel laterally diffused metal-oxide semiconductor field-effect transistors with different drift region lengths are examined after exposure to total ionizing dose. The variation observed is analyzed using technology computer-aided design simulation.