Driven by the requirement to ultraviolet detection, β-Ga₂O₃ UV photodetectors have attracted great attention. Using a metal organic chemical vapor deposition (MOCVD) reactor, we grew β-Ga₂O₃ nanowires array on a GaN substrate using Ga as catalyst. The density of the nanowires was optimized employing the substrate patterning technology. A UV detector based on the graphene/β-Ga₂O₃-nanowire-array was realized by micro-fabrication techniques. The device has a wide range of UV response covering UVC-UVA band and the peak response reaches 30.82 mA W⁻¹ at 258 nm corresponding to the band gap of β-Ga₂O₃. The rapid response speed (<1 s) is comparable to that of most reported Ga₂O₃ nanowire ultraviolet photodetectors.

In this article, we investigated the electrical characteristics of the high-voltage β-gallium oxide (Ga₂ O₃) vertical U-shaped trench gate MOSFETs (UMOSFETs) based on a current blocking layer (CBL) under varying nitrogen ions implantation concentrations and activation annealing temperatures. When the nitrogen ions implantation concentration is 4 × 10¹⁹ cm^-3 and the activation annealing temperature is 1200 ^∘C, the fabricated device achieved the highest breakdown voltage (V_br) exceeding 1.3 kV without field plates, while obtaining an ON-resistance (R$_{\biosc{on}}$) of 132.35 mΩ⋅cm². Additionally, at a nitrogen ions implantation concentration of 2 × 10¹⁹ cm^-3 and an activation annealing temperature of 1100 ^∘C, the device achieved a V_br of 985 V, R$_{\biosc{on}}$ of 24.37 mΩ⋅cm², and a power figure-of-merit (PFOM) of 40 MW/cm². Our findings indicate that the current blocking capability of the CBL and V_br improved with the increase in nitrogen ions implantation concentration and activation annealing temperature, while an increase in device R_on was observed. Overall, this work demonstrates the potential for achieving high-performance β-Ga₂O₃ UMOSFETs with nitrogen ions implantation.

A quasi-vertical Schottky diodes with high speed and high responsivity were demonstrated by epitaxially growing Ga ₂ O ₃ on Pt. The research further investigated the impact of incorporating metal stripes in the photosensitive region to enhance both the responsivity and response speed of the device. Characterization of the photoresponses reveals that these devices exhibit high sensitivity to solar-blind ultraviolet light, peaking at approximately 260 nm. At the bias of -5V, the detector achieves a responsivity of 2998 A/W, an exceptional specific detectivity of 1.68×10 ⁷ Jones and a high response speed about 0.1 ms. By applying these metrics demonstrate substantial improvements over existing technologies and suggest a promising avenue for developing high speed and high responsivity photodetectors.

The temperature sensitivity is one of the critical parameters for the thin film bulk acoustic resonator (FBAR) based temperature sensors. In this work, FBARs with Au/Fe_0.8Ga_0.2/Ti/AlN/Mo structure are developed. The size effect of the Ti insertion layer on the temperature sensitivity of the devices is systematically investigated. The devices were fabricated by MEMS process and characterized by a network analyzer under variable temperatures. It is found that the temperature sensitivity of the devices is strongly related to the thickness of the Ti insertion layer. A super-high temperature sensitivity up to 546 kHz °C⁻¹ was obtained with 20 nm Ti inserted thin film; that feature can even reach 825 kHz °C⁻¹ for some devices, showing great potential for ultra-sensitive temperature monitoring. Mason model is used to analyze the extraordinary characteristics of the device and finite element method (FEM) is used to analyze the strain distribution in the device. The supreme performance of the temperature sensor can be explained by the size effect of the temperature coefficient of Young’s modulus (TCE) of Ti film, which means that the TCE was enhanced when the thickness of the Ti film is around 20 nm. This work provides a new approach for the design of high sensitivity temperature sensor based on FBAR.

We performed dry oxidation on n-type silicon carbide (SiC), followed by annealing in diluted N₂O, and subsequently fabricated n-type MOS structures. The study aimed to investigate the impact of different annealing times on the trap charges near the SiC/SiO₂ interface and the reliability of the gate dielectric. Capacitance-voltage (C-V) and current-voltage (I-V) measurements of the n-type MOS revealed that increasing the annealing time with N₂O effectively reduces the density of electron traps near the SiC/SiO₂ interface, mitigates the drift in flat-band voltage and enhances the oxide breakdown field strength. However, excessive annealing time leads to an increase in the flat-band voltage drift of the MOS, resulting in premature oxide breakdown. Using the optimized annealing conditions, we fabricated n-type LDMOSFETs and obtained the threshold voltage (Vth), field-effect mobility (μ_FE) and specific on-resistance (Ron-sp) from the transfer curve (Id-Vg) and output curve (Id-Vd) measurements. The research findings provide valuable insights for the gate oxidation process of SiC.