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The floating Island (FI) device has a severe turn-on recovery problem. In this brief, a new “metal bridge” that connects the Island and the N+ buffer through ohmic contact is proposed. The objective of the new structure is to resolve the turn-on recovery problem. Simulations are conducted to validate the efficacy of the structure. The proposed FI junction barrier Schottky with the proposed metal bridge (MB-FIJBS) shows no voltage overshoot and has significantly reduced the recovered on-state voltage compared to the conventional junction barrier Schottky (Conv. JBS). The recovered on-state voltage of the MB-FIJBS is the same as its static On-state voltage, proving a complete recovery. The mechanism of the turn-on process of the MB-FIJBS is elucidated. The MB-FIJBS achieves rapid recovery by completely removing any additional potential barrier in the current flow path. The MB-FIJBS is well designed, so that it does not degrade the breakdown voltage (BV). The 3-D implementation of the MB-FIJBS is proposed to provide a practically feasible structure that is compatible with the current manufacturing process. A simulation of the 3-D structure has been conducted to validate its effectiveness.

The poor interface of silicon carbide (SiC)/SiO2 combined with the short channel effects (SCEs) and source contact resistance, collectively impacts the effective threshold voltage in SiC MOSFETs. In this work, a physical discrete channel model was proposed to analyze the influence of the combined effects of varying channel lengths, as well as applied drain and gate voltages. The proposed model was validated through TCAD simulation and by the fabricated SiC power MOSFETs. This model was applicable to MOSFETs with both symmetric and asymmetric channels considering various interface state density distributions. The influence of these factors on effective threshold voltage was also discussed considering variations in source contact resistance and channel doping concentration. Through the analysis of the model results, it was found that the interface states significantly impact the effective threshold voltage through different mechanisms while the SCEs are mitigated by the unsaturated interface states.

In this work, a snapback-free and fast-switching silicon-on-insulator lateral insulated-gate bipolar transistor (SOI-LIGBT) with reverse conducting (RC) capability is proposed and investigated by TCAD simulations. The proposed device features an anode p-type polysilicon trench (PT) and a p-type doping region between n+ anode and n-buffer (PR) named PTR-LIGBT. The PT is directly connected to the anode and driven by the anode voltage without any additional control circuits. At the forward conducting state, PT and PR will create electron barriers along the electron path. Those dual barriers will block the flow of electrons to the n+ anode. As a result, by introducing these two structures, the snapback phenomenon is eliminated in this novel PTR-LIGBT. Moreover, at the RC state, the barriers will decrease gradually with the increase of voltage, so that the RC capability is ensured. The simulation results show that, compared with SSA-LIGBT, the reverse recovery time ( ${t}_{\text {rr}}$ ) and reverse recovery charge ( ${Q}_{\text {rr}}$ ) of the monolithic diode of PTR-LIGBT are reduced by 65.34% and 18.59%, respectively. ${V}_{F}$ of PTR-LIGBT is reduced by 16.52% under the same ${E}_{\text {off}}$ , and ${V}_{F}$ of PTR-LIGBT is reduced by 20.63% under the same ${T}_{\text {off}}$ .

In this article, we delve into the intricacies of carrier population and depletion in AlGaN/GaN multichannel structures through a combination of TCAD numerical simulations and theoretical modeling. Here, we take into account the unintentional or intentional n-type doping commonly seen in experimental multichannel devices. The impact of doping and layer thickness on the carrier population in the multichannel, as well as the carrier depletion and ${C}-{V}$ characteristics, is investigated. The simulation results demonstrate that the doping in the AlGaN layer disrupts the balance between the 2-D electron gas (2DEG) and 2-D hole gas (2DHG), but the charge balance can be re-established with an additional pGaN layer on top of the multichannel structure. This pGaN layer can deplete the excessive electrons at high bias, resulting in a nearly flat electric field distribution. Moreover, an analytical model of the blocking electric field and conduction resistance in multichannel devices is built and validated by simulation. With this model, the impact of channel quantities on the device figure-of-merit (FOM) is studied and the optimization guideline of structure parameters is provided. This study provides key insights into the physics, performance space, and prospects of the multichannel gallium nitride (GaN) power devices.