Devices under semi-on-state stress often suffer from more severe current collapse than when they are in the off-state, which causes an increase in dynamic on-resistance. Therefore, characterization of the trap states is necessary. In this study, temperature-dependent transient recovery current analysis determined a trap energy level of 0.08 eV under semi-on-state stress, implying that interface traps are responsible for current collapse. Multi-frequency capacitance–voltage (C-V) testing was performed on the MIS diode, calculating that interface trap density is in the range of $1.37\times {10}^{13}$ to $6.07\times {10}^{12}$${\mathrm{cm}}^{-2}$${\mathrm{eV}}^{-1}$ from $E_C-E_T=0.29$ eV to 0.45 eV.

A monolithically integrated voltage reference based on p-GaN HEMT technology is demonstrated in this work. The proposed two-stage structure can improve the stability of the generated reference voltage over a wide range of the supply voltage and temperature. The static and dynamic performance was measured at various temperatures. Experimental results indicate that the output voltage is stable at 1.3 V when the supply voltage rises from 2.8 V to 40 V, with a line sensitivity of 0.035 %/V at room temperature. When the measurement temperature increases to 250 ∘C, the generated reference voltage slightly decreases to 1.25 V with a temperature coefficient of -22.1 ppm/∘C. The power supply rejection ratio of this work is competitive, as the power supply rejection ratio changes from -46.64 dB to -56.2 dB, in which the noise frequency varies from 10 Hz to 5 MHz. The voltage variation of the generated reference voltage is relatively small when the frequency exceeds 5 MHz. The results show that the proposed work is particularly suitable for all-GaN monolithic integration circuits that require thermally stable bias voltages with high immunity to the supply voltage variation.

Owing to the lack of high-quality thick oxides formed by in situ oxidation, gallium nitride (GaN) trench MOSFETs are subject to pronounced electric field crowding at the trench bottom corners, which limits their off-state blocking capability. In this work, based on a GaN-on-silicon (Si) epitaxy, a thick SiO₂ deposition process was applied to the trench bottom. This approach effectively redistributes the electric field, shifting the field concentration from the dielectric/GaN corners into a 300-nm SiO₂ layer. This terminal structure makes the device breakdown more dependent on the intrinsic blocking capability of GaN rather than on premature electric-field crowding at the trench bottom corners. As a result, a state-of-the-art breakdown voltage of 787 V was achieved for the quasi-vertical structure on a heterogeneous substrate. Furthermore, the device with the thick bottom oxide also exhibits a high threshold voltage (V_th) of 7.6 V, an on/off ratio exceeding $\text{10}^{\text{7}}$ , a specific on-resistance (R ${}_{ \text {on},\text {sp}}$ ) of 3.9 m $\Omega \cdot \text {cm}^{\text{2}}$ , and a Baliga’s figure of merit (BFOM) of 159 MW/ $\text {cm}^{\text{2}}$ , demonstrating the promise of this process for GaN-on-Si trench MOSFETs in future high-power electronics.

In this work, a high-performance ultraviolet (UV) photodetector (PD) based on p-NiO/AlGaN/GaN structure is proposed for optical switching or UV detection. With its good photosensitivity, a high photocurrent of 39.75 mA/mm is achieved with UV illumination. Moreover, due to the depletion of the two-dimensional electron gas by the p-NiO layer, the dark current is reduced to 5.85 × 10^-6 mA/mm. Hence, a high photo-to-dark current ratio of 6.79 × 10⁶ is achieved in this work. Furthermore, the voltage output signal is generated through monolithically integrated two-dimensional electron gas resistors, achieving a rise time τ_rise of 0.86 ms and a fall time τ_fall of 1.33 ms, respectively. This output can be directly interfaced with logic circuits without requiring an additional conversion circuit. The monolithic integration design reduces parasitic effects, thereby enhancing operating frequency. These results indicate the suitability of the proposed GaN PDs for high-sensitivity UV detection.