Owing to the superior properties of silicon carbide (SiC), such as higher breakdown voltage, higher thermal conductivity, higher operating frequency, higher operating temperature, and higher saturation drift velocity, SiC has attracted much attention from researchers and the industry for decades. With the advances in material science and processing technology, many power applications such as new smart energy vehicles, power converters, inverters, and power supplies are being realized using SiC power devices. In particular, SiC MOSFETs are generally chosen to be used as a power device due to their ability to achieve lower on-resistance, reduced switching losses, and high switching speeds than the silicon counterpart and have been commercialized extensively in recent years. A general review of the critical processing steps for manufacturing SiC MOSFETs, types of SiC MOSFETs, and power applications based on SiC power devices are covered in this paper. Additionally, the reliability issues of SiC power MOSFET are also briefly summarized.

Due to the emergence of electric vehicles, power electronics have become the new focal point of research. Compared to commercialized semiconductors, such as Si, GaN, and SiC, power devices based on β-Ga2O3 are capable of handling high voltages in smaller dimensions and with higher efficiencies, because of the ultrawide bandgap (4.9 eV) and large breakdown electric field (8 MV cm–1). Furthermore, the β-Ga2O3 bulk crystals can be synthesized by the relatively low-cost melt growth methods, making the single-crystal substrates and epitaxial layers readily accessible for fabricating high-performance power devices. In this article, we first provide a comprehensive review on the material properties, crystal growth, and deposition methods of β-Ga2O3, and then focus on the state-of-the-art depletion mode, enhancement mode, and nanomembrane field-effect transistors (FETs) based on β-Ga2O3 for high-power switching and high-frequency amplification applications. In the meantime, device-level approaches to cope with the two main issues of β-Ga2O3, namely, the lack of p-type doping and the relatively low thermal conductivity, will be discussed and compared.

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A typical method for normally-off operation, the metal–insulator–semiconductor-high electron mobility transistor (MIS-HEMT) has been investigated. Among various approaches, gate recessed MIS-HEMT have demonstrated a high gate voltage sweep and low leakage current characteristics. Despite their high performance, obtaining low-damage techniques in gate recess processing has so far proven too challenging. In this letter, we demonstrate a high current density and high breakdown down voltage of a MIS-HEMT with a recessed gate by the low damage gate recessed etching of atomic layer etching (ALE) technology. After the remaining 3.7 nm of the AlGaN recessed gate was formed, the surface roughness (Ra of 0.40 nm) was almost the same as the surface without ALE (no etching) as measured by atomic force microscopy (AFM). Furthermore, the devices demonstrate state-of-the-art characteristics with a competitive maximum drain current of 608 mA/mm at a VG of 6 V and a threshold voltage of +2.0 V. The devices also show an on/off current ratio of 109 and an off-state hard breakdown voltage of 1190 V. The low damage of ALE technology was introduced into the MIS-HEMT with the recessed gate, which effectively reduced trapping states at the interface to obtain the low on-resistance (Ron) of 6.8 Ω·mm and high breakdown voltage performance.