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The impact of heavy ion irradiation on the β-Ga2O3 p-n diode and its physical mechanism have been studied in this Letter. After the irradiation fluence of 1 × 108 cm−2, it is observed that the electrical performance of the device is significantly degraded. The forward current density (JF) is reduced by 49.4%, the reverse current density (JR) is increased by more than two orders of magnitude, and the breakdown voltage (VBR) is decreased by 30%. Based on the results of the deep-level transient spectroscopy measurement, it is concluded that acceptor-like traps generated with an energy level of EC-0.75 eV in the β-Ga2O3 drift layer dominate the JF degradation of the device, which are most likely related to Ga vacancies. These acceptor-like traps result in the reduction of change carrier concentration, which in turn leads to a decrease in JF. In addition, according to the conductive atomic force microscope measurements and theoretical calculation, it is clearly observed that the latent tracks induced by heavy ion irradiation can act as leakage paths, leading to a significant degradation of JR and VBR. [ABSTRACT FROM AUTHOR]

In this work, the influence of the Fe and Fe/C co-doped buffer on the AlGaN/GaN HEMTs is systematically investigated and compared. Due to the pronounced Fe tail in the unintentionally doped layer of the Fe-doped buffer compared to the Fe/C co-doped buffer, and the utilization of a two-step C doping process in the Fe/C co-doped buffer, it results in effectively reducing leakage current and increasing breakdown voltage without sacrificing saturation current and peak transconductance. Meanwhile, the RF characteristics of the Fe/C co-doped buffer are also superior to the Fe-doped buffer. More importantly, Drain Transient Current measurements indicate that the current collapse in the Fe/C co-doped buffer is smaller than that in the Fe-doped buffer. Through simulation analysis, the reason was identified: In the near-channel region, the weaker Fe tail effect in Fe/C co-doped buffer leads to a lower acceptor trap ionization. When the concentration of C exceeds 1 × 1016 cm−3, the ionization of traps introduced by Fe is suppressed. Additionally, the two-step C impurity distribution in the Fe/C co-doped buffer design modulates the electric field and potential, reducing the effective range of the electric field and potential, thereby effectively reducing the trap effects. These results are highly meaningful for the design of high-power amplifier epitaxial structures. [ABSTRACT FROM AUTHOR]

This document is a collection of research papers on wide- and ultrawide-bandgap electronic semiconductor devices. It focuses on the progress and challenges in developing devices made from wide-bandgap materials like GaN, AlGaN, AlN, Ga2O3, BN, and diamond for power, rf, and photonic applications. The papers cover topics such as improving GaN power devices, exploring new wide bandgap materials, and investigating gate insulator properties. Additionally, there are papers on defect detection, new concepts for wide bandgap devices, and the growth and properties of different materials. The research provides valuable insights for researchers interested in using these materials in electronic devices. [Extracted from the article]

In this Letter, an enhancement mode (E-mode) β-Ga2O3 metal-oxide-semiconductor field-effect transistor (MOSFET) with quasi-two-dimensional channel was reported, and the channel mobility of 147.5 cm2/(V·s) is achieved. Low damage etching technology and low Ohmic contact resistance technology are introduced. As a result, the E-mode transistor demonstrates a maximum drain to source current (ID) of 230.5 mA/mm, a peak transconductance (Gm) of 54.2 mS/mm, a current gain cut-off frequency (fT) of 18 GHz, and a power gain cut-off frequency (fMAX) of 42 GHz. Additionally, a positive threshold voltage (VT) of 1.65 V, a breakdown voltage (VBK) of 420 V, and a specific on-resistance (RON,SP) of 1.24 mΩ·cm2 are achieved. Moreover, a fMAX × VBK of 17.64 THz·V and a fT × VBK of 7.56 THz·V are found to be a close value so far to the theoretical limit of β-Ga2O3. This device leads to excellent radio frequency (RF) characteristics, which paved the way for future millimeter-wave RF power electronics applications with β-Ga2O3 MOSFET. [ABSTRACT FROM AUTHOR]

The application of GaN HEMTs on silicon substrates in high-voltage environments is significantly limited due to their complex buffer layer structure and the difficulty in controlling wafer warpage. In this work, we successfully fabricated GaN power HEMTs on 6-inch sapphire substrates using a CMOS-compatible process. A 1.5 µm thin GaN buffer layer with excellent uniformity and a 20 nm in situ SiN gate dielectric ensured uniformly distributed VTH and RON across the entire 6-inch wafer. The fabricated devices with an LGD of 30 µm and WG of 36 mm exhibited an RON of 18.06 Ω·mm and an off-state breakdown voltage of over 3 kV. The electrical mapping visualizes the high uniformity of RON and VTH distributed across the whole 6-inch wafer, which is of great significance in promoting the applications of GaN power HEMTs for medium-voltage power electronics in the future. [ABSTRACT FROM AUTHOR]

To improve the threshold voltage and gate reliability of conventional enhancement-mode p-GaN-gated AlGaN/GaN high electron mobility transistors while maintaining a low on-resistance, an improved design solution for p-GaN HEMTs with P-I-N junction gate (PIN-HEMTs) has been proposed. Simulation results show that energy band modulation is achieved by adjusting the doping concentration and thickness of each layer of the PIN junction, and high-performance p-GaN gate HEMTs with adjustable threshold voltages ranging from 0.56 V to 4.75 V and gate breakdown voltages ranging from 19.8 V to 30.3 V would be prepared. The PIN-HEMT has a quasi-self-alignment property, which means that good gate control is independent of gate metal alignment. This not only improves the production efficiency but also solves the problems of weak gate control and electric field aggregation at the gate edge caused by the gate misalignment in conventional p-GaN gate HEMTs, thus realizing lower on-resistance and higher gate breakdown voltage, which demonstrates this proposed structure has excellent potentials for realizing effective and reliable high-power transistors. [ABSTRACT FROM AUTHOR]

In this work, we propose combining a low work function anode metal and junction barrier Schottky structure to simultaneously achieve low turn-on voltage (Von) and high breakdown voltage (BV), which alleviates the dilemma that high BV requires high Schottky barrier height (SBH) and high Von. Molybdenum (Mo) is used to serve as the anode metal to reduce the SBH and facilitate fast turn-on to achieve a low Von. To resolve the low SBH related low BV issue, a p-NiO/n-Ga2O3-based heterojunction structure is used to enhance β-Ga2O3 sidewall depletion during the reverse state to improve the BV. With such a design, a low Von = 0.64 V(@1A/cm2) and a high BV = 2.34 kV as well as a specific on-resistance (Ron,sp) of 5.3 mΩ cm2 are demonstrated on a 10 μm-drift layer with a doping concentration of 1.5 × 1016 cm−3. β-Ga2O3 JBS diodes with low Von = 0.64 V and a power figure of merit of 1.03 GW/cm2 show great potential for future high-voltage and high-efficiency power electronics. [ABSTRACT FROM AUTHOR]

The density of interface states is strongly related to the performance of AlGaN/GaN high-electron-mobility transistors (HEMTs) and is normally attributed to the degradation of the carrier mobility and gate leakage current. The density of interface states is optimized in conventional AlGaN/GaN HEMTs through the use of different passivation layers. However, different passivation layers may create more complex interface structures. In our previous work, ferroelectric polarization was used to regulate the carrier concentration in AlGaN/GaN HEMTs. Herein, we propose a ferroelectric passivation-layer-induced pure field effect modulation within the AlGaN/GaN heterojunction field-effect transistors. After positive poling, the interface trap density (D i t ) decreases by 71% and current collapse is reduced. The output current (I D S ) increases from 408 to 462 mA/mm and transconductance (g m) increases from 88 to 149 mS/mm. Simultaneously, the carrier mobility in the channel is also greatly improved after positive poling. When negative poling is applied, the gate leakage decreases and the breakdown voltage of the device increases by 55%. Our work provides a simple and effective way to study the density of interface states in GaN device design and optimization. [ABSTRACT FROM AUTHOR]

In this work, we demonstrated the enhancement mode (E-mode) β-Ga2O3 metal–oxide–semiconductor field-effect transistor (MOSFET) by introducing a hybrid floating gate (HFG) structure. This E-mode Ga2O3 MOSFET featured the highest VTH of 9.03 V and the highest maximum current ID of 70.0 mA/mm among the reported lateral normally off β-Ga2O3 MOSFETs. Meanwhile, a breakdown voltage of 834 V, a specific on-resistance RON,sp of 19.3 mΩ·cm2, and a sub-threshold swing SS of 87 mV/dec were achieved simultaneously. In addition, VTH shifted by only 9.9% after applying a gate stress of 25 V for 105 s. These findings provide a promising path for the development of enhancement-mode Ga2O3 power devices by incorporating a charge-storage structure. [ABSTRACT FROM AUTHOR]

Passivation is commonly used to suppress current collapse in AlGaN/GaN HEMTs. However, the conventional PECV-fabricated SiNx passivation layer is incompatible with the latest process, like the "passivation-prior-to-ohmic" method. Research attention has therefore turned to high-temperature passivation schemes. In this paper, we systematically investigated the differences between the SiNx/GaN interface of two high-temperature passivation schemes, MOCVD-SiNx and LPCVD-SiNx, and investigated their effects on the ohmic contact mechanism. By characterizing the device interface using TEM, we reveal that during the process of MOCVD-SiNx, etching damage and Si diffuses into the semiconductor to form a leakage path and reduce the breakdown voltage of the AlGaN/GaN HEMTs. Moreover, N enrichment at the edge of the ohmic region of the LPCVD-SiNx device indicates that the device is more favorable for TiN formation, thus reducing the ohmic contact resistance, which is beneficial to improving the PAE of the device. Through the CW load-pull test with drain voltage VDS = 20V, LPCVD-SiNx devices obtain a high PAE of 66.35%, which is about 6% higher than MOCVD-SiNx devices. This excellent result indicates that the prospect of LPCVD-SiNx passivation devices used in 5G small terminals will be attractive. [ABSTRACT FROM AUTHOR]

In this Letter, we demonstrate the Schottky gated p-AlGaN/u-GaN/AlGaN p-channel field-effect transistors (p-FETs) with an extremely low interface state density of 2.5 × 1011 cm−2 eV−1. Benefiting from the high-quality Schottky interface with suppressed interface states, the excellent stability with negligible hysteresis is proved, even after ten sequential dual I–V sweeps at 150 °C. Meanwhile, the trap density, confirmed by the temperature-dependent conductance method, is still below 1012 cm−2 eV−1 at high temperature. Furthermore, the fabricated p-AlGaN/u-GaN/AlGaN p-FET with a gate to drain distance of 1.8 μm shows a breakdown voltage of −128 V and an effective on-resistance of 7.2 kΩ mm, which allows the further scale down in terms of the source–drain spacing to improve the conduction current for low voltage application. The ultra-stable I–V characteristics of the fabricated Schottky-gated p-AlGaN/u-GaN/AlGaN p-FETs show great potential for next-generation integrated circuit application at high temperatures. [ABSTRACT FROM AUTHOR]

This study proposes a β‐Ga2O3 pn tunneling diode (PNT‐diode) in which the p‐type region is obtained by sputtering a thin NiOx layer in the pure argon atmosphere. The diode exhibits good characteristics: a high current density of 1530 A cm−2 at 10 V and a low specific on‐resistance of 0.56 mΩ cm2. Moreover, its breakdown voltage of is about four times compared to a conventional diode, and its Baliga's figure of merit (BFOM) is as high as 3.25 GW cm−2. Ni/NiOx diodes are simulated by Silvaco simulation software to investigate the physical mechanism of the low specific on‐resistance of the PNT‐diode, and the results demonstrate that Ni and NiOx can form a reverse diode, and that PNT‐diode is equivalent to the Ni/NiOx reverse diode and the NiOx/β‐Ga2O3 forward diode connected in series. Finally, the electric field distribution of the PNT‐diode is simulated, and it is found that p‐type NiOx can significantly reduce the peak electric field at the anode edge. [ABSTRACT FROM AUTHOR]

In this work, the effects of proton-induced trap evolution on the electrical performances of AlGaN/GaN metal–insulator–semiconductor (MIS) high-electron-mobility-transistors (HEMTs) have been investigated in detail. Contrary to observed proton-induced degradation in sheet electron density (ns), carrier mobility (μn), and sheet resistance (RSH), a significant improvement in gate leakage current (IG) and off-state drain–source breakdown voltage (BVDS) is found in irradiated devices. The low-frequency noise (LFN) results show that the density of traps in the AlGaN layer and AlGaN/GaN interface increases after irradiation, which leads to a degradation in ns, μn, and RSH and an improvement in BVDS due to enhanced electron trapping and depletion. Furthermore, the measurement results obtained from the frequency-dependent conductance technique show that irradiated devices exhibit decreased trap density (DT) at the insulator/semiconductor interface with hardly changed trap energy level (ET), which confirms the observed proton-induced decrease in IG. An increase in DT at the AlGaN/GaN interface is also found after irradiation, which is consistent with LFN results. These traps with deeper ET induce a serious Coulomb scattering effect. This work provides valuable information for the systematic understanding of the proton irradiation effect of AlGaN/GaN MIS-HEMTs. [ABSTRACT FROM AUTHOR]

This Letter reports two kinds of oxygen-containing plasma treated β-Ga2O3 Schottky barrier diodes (SBDs), including N2O plasma treatment and O2 plasma treatment, and the SBD without plasma is prepared for comparison. I–V characteristics, breakdown characteristics, and trap state characteristics of three devices have been studied. It is found that the turn-on voltage of SBDs with N2O plasma can reduce to 0.6 V, and the better current density of 750 A/cm2 and an on-resistance of 3.5 mΩ cm2 are obtained after the N2O plasma treatment. Moreover, the breakdown voltage of SBDs with N2O plasma is 50.2% higher than the conventional one, whose value reaches 323 V. In addition, the trap states' characteristics of the devices are studied, which show that the oxygen-containing plasma can reduce the deep level trap states density partly in the anode region, which can improve the surface quality effectively. [ABSTRACT FROM AUTHOR]

In this work, high-performance high-electron-mobility transistors (HEMTs) with a thin GaN channel and an AlN back barrier were fabricated and investigated in detail. The AlN back barrier HEMTs possess a higher current density and a better linearity than traditional devices. In addition, the off-state leakage current of the AlN back barrier HEMTs is more than one order of magnitude lower than that of traditional devices with a high-resistance Fe-doped GaN buffer, even though they do not involve any intentional doping technique. Additionally, the high-temperature performance of the AlN back barrier HEMTs is excellent, with less attenuation in the drain current density and less increase in the off-state leakage current. Moreover, the breakdown voltage of the AlN back barrier HEMTs is as high as 309 V with an LGD of 2.5 μm, resulting in a high Baliga figure of merit of 0.354 GW/cm2. The superior performance of the AlN back barrier devices is further demonstrated by the calculation and simulation results. The results in this work not only show the great potential of AlN back barrier HEMTs but also provide a useful direction for overcoming the limiting issues of nitride devices. [ABSTRACT FROM AUTHOR]

Synthesized β-Ga2O3 nanobelts have excellent electrical and optical properties. However, their widths are mostly limited to only a few microns or even tens of nanometers by far, which presents the big challenge for the fabrication of nanodevices and nanosensors. In this work, the β-Ga2O3 single crystal nanobelts synthesized by carbothermal reduction have the ultra-large widths which can reach up to 145 μm. Schottky barrier diode based on the nanobelt shows the impressive UV-induced rectifying characteristics due to ultra-low dark current of 100–200 fA at forward bias. At 5 V and 15 V, its ratios of current under 254 nm UV condition and that under dark condition are as high as 5 × 105 and 1.4 × 106, respectively. Meanwhile, the diode also has the high breakdown voltage of 240 V. [ABSTRACT FROM AUTHOR]

GaN JBS diodes exhibit excellent performance in power electronics. However, device performance is affected by multiple parameters of the P+ region, and the traditional TCAD simulation method is complex and time-consuming. In this study, we used a neural network machine learning method to predict the performance of a GaN JBS diode. First, 3018 groups of sample data composed of device structure and performance parameters were obtained using TCAD tools. The data were then input into the established neural network for training, which could quickly predict the device performance. The final prediction results show that the mean relative errors of the on-state resistance and reverse breakdown voltage are 0.048 and 0.028, respectively. The predicted value has an excellent fitting effect. This method can quickly design GaN JBS diodes with target performance and accelerate research on GaN JBS diode performance prediction. [ABSTRACT FROM AUTHOR]

In this paper, Silvaco TCAD software is used to simulate the buffer traps in AlGaN/GaN high electron mobility transistors (HEMTs), and its effects on the breakdown performance and key parameters of the devices are investigated by changing the position and concentration of the acceptor traps in the buffer layer. The results show that with the increase of trap concentration, the traps capture electrons and reduce the off-state leakage current, which can improve breakdown voltage of the devices. At the same time, as the trap concentration increases, the ionized traps make a high additional electric field near the drain edge, leading to the decrease of breakdown voltage. With the combined two effects above, the breakdown voltage almost ultimately saturates. When the source-to-gate (Access-S) region in the GaN buffer layer is doped alone, the minimum and most linear leakage current for the same trap concentrations are obtained, and the additional electric field has a relatively small effect on the electric field peak near the drain as the ionized traps are furthest from drain. All these factors make the breakdown voltage increase more controllably with the Access-S region doping, and it is a more potential way to improve the breakdown performance. [ABSTRACT FROM AUTHOR]

This letter reports on the demonstration of recessed-gate ultra-wide bandgap semiconductor Al0.6Ga0.4N MOSFET with Hf0.5Zr0.5O2 (HZO) ferroelectric charge storage dielectric structure. A positive threshold voltage ($\text{V}_{\text {TH}}$) of 3.550 V and maximum gate swing of 15 V is achieved due to the trapped electrons induced by remnant polarization of HZO in gate stack. The Al0.6Ga0.4N MOSFET exhibits a specific on-resistance ($\text{R}_{\text {on,sp}}$) of ${17.8} \text {m}~\Omega \cdot \text {cm}^{{2}}$. Moreover, an 840 V breakdown voltage (BV) is obtained with a gate-to-drain ($\text{L}_{\text {gd}}$) length of $2 ~\mu \text{m}$ , indicating an average breakdown electric field ($\text{E}_{\text {av}}$) beyond 4 MV/cm. In addition to the high $\text{E}_{\text {av}}$ , a high BV > 3 kV is also derived on a transistor with $\text {L}_{\text {gd}} = {8}\,\,\mu \text {m}$ , translating to a power figure-of-merit (P-FOM=BV2/ $\text{R}_{\text {on,sp}}$) of 208 MW/cm2. These high device performances indicate a great potential of Al-rich E-mode AlGaN MOSFET for future high-power applications. [ABSTRACT FROM AUTHOR]

In this Letter, lateral slanted-fin-channel β-Ga2O3 metal-oxide-semiconductor field effect transistors (MOSFETs) are demonstrated. A 600-nm thick n-type doped channel layer is adopted to improve output characteristics. The tri-gate structure enhances gate control in the proposed β-Ga2O3 MOSFETs, showing an on/off ratio as high as 109. In particular, the slanted-fin-channel structure, mainly located in the gate region, reduces the peak electric field in the Ga2O3 channel due to the gradual regulation of a threshold voltage. The slanted-fin-channel β-Ga2O3 MOSFETs show a breakdown voltage (Vbr) of 2400 V and a power figure-of-merit of 193 MW/cm2, which are almost 2 and 5.5 times larger, respectively, than those of conventional straight-fin-channel devices. These results imply that the slanted-fin channel structure provides a viable way of fabricating high-performance β-Ga2O3 MOSFET power devices. [ABSTRACT FROM AUTHOR]

In this letter, a linearity enhancement AlGaN/ GaN high electron mobility transistor (HEMT) with high power density and high efficiency has been achieved by selective-area charge implantation (SCI) for X-band application. Device-level transconductance compensation is realized by an under-gate SCI technique, which greatly improves the linearity of the device. The device presents a maximum drain current of 1390 mA/mm and a peak transconductance of 230 mS/mm. The gate voltage swing is up to 5.2 V, which is double of the conventional devices. At 12 GHz with a drain voltage of 25 V, the SCI device exhibits a peak power added efficiency of 47 % and a saturated output power density of 6.7 W/mm. In addition, the two-tone measurement results at 12 GHz show that the SCI device manifest an excellent linearity figure of merit OIP3/ $\text{P}_{\text {DC}}$ of 11.2 dB, whereas that of the conventional HEMTs is only 5.5 dB. These results suggest SCI HEMTs have immense potential for microwave power amplifiers requiring high linearity. [ABSTRACT FROM AUTHOR]

Low-damage plasma oxidation treatment for AlN/GaN high-electron-mobility transistors (HEMTs) was developed in this letter, with which high-performance enhancement-mode (E-mode) AlON/AlN/GaN HEMTs were demonstrated. After removal of in situ SiN cap layer within gate area, remote plasma oxidation (RPO) treatment of 4.9nm AlN barrier layer at 300 °C leads to formation of AlON insulator layer and effective depletion of 2-D electron gas channel, without etch-induced damage or serious interfacial issues compared with the commonly used gate- recess metal-insulator-semiconductor HEMTs. Thanks to the low-damage RPO treatment, the achieved E-mode HEMTs with threshold voltage of 0.4 V exhibit quite a small loss of output current (7.8%) compared with the depletion-mode devices. In addition, the AlON gate insulator layer results in a remarkable increase in breakdown voltage of devices from 20 V to 74 V, which benefits the high-voltage operation of AlN/GaN technology. Further investigation shows that the oxidation process of AlN barrier tends to be saturated with treatment time increasing, providing a promising solution to the high-performance E-mode operation of scaled GaN-based HEMTs in RF applications. [ABSTRACT FROM AUTHOR]

In this work, high-performance GaN vertical Schottky barrier diodes (SBDs) are successfully fabricated on the GaN-on-GaN substrate by using the self-alignment trench structure and argon (Ar) ion implantation. The fabricated diodes achieve a high current ON/ OFF ratio of 108 and high breakdown voltage (BV) of 656 V due to the reduced surface electric field effect. Besides, the temperature-dependent reverse leakage characteristics show that two Poole–Frenkel emission (PFE) processes dominate the carrier transport. This work shows great potential of the self-alignment trench structure in fabricating GaN vertical SBDs to improve the BV with simply fabrication process. [ABSTRACT FROM AUTHOR]

In this work, a high performance GaN-on-Si quasi vertical PiN diode was demonstrated by the combination of a beveled sidewall and self-aligned fluorine plasma treatment. The didoes achieved a remarkable breakdown voltage ($\text{V}_{\text {BR}}{)}$ of 930 V and an ultra-low reverse leakage current. Meanwhile the didoes showed a low specific on-resistance ($\text{R}_{ \mathrm{\scriptscriptstyle ON},\textit {sp}}$) of 0.43 $\text{m}\Omega \cdot $ cm2, a high on/off current ratio ($\text{I}_{ \mathrm{\scriptscriptstyle ON}}/\text{I}_{ \mathrm{\scriptscriptstyle OFF}}$) of $10^{{11}}$ , and an excellent Baliga’s figure of merit (BFOM) of 2.01 GW/cm2. The measurement results of X-ray spectroscopy (XPS) and Kelvin Probe Force Microscopy (KPFM) proved the presence of F ions and the decrease of surface potential, which reduced the electric field peak and suppressed the leakage current. These results show a great potential of GaN on Si PiN diode for power applications. [ABSTRACT FROM AUTHOR]

A hybrid Schottky–ohmic drain technology for millimeter-wave (mmW) AlGaN/GaN high-electron-mobility transistors (HEMTs) is proposed. The Schottky metal extension in the ohmic region of drain reduces the actual source–drain spacing, resulting in a smaller ON-resistance and a higher maximum current. Extended Schottky metal in the drain region modulates the electric-field distribution, thereby leading to an improved breakdown voltage, suppressed current collapse, and high reliability. Compared with the ohmic drain, the current gain cutoff frequency (${f}_{T}$) was improved from 64 to 76 GHz, and the maximum oscillation frequency (${f}_{\text {max}}$) was improved from 125 to 157 GHz, resulting from the decreased parasitic drain resistance (${R}_{d}$). Moreover, large-signal measurements in continuous wave (CW) at 30 GHz demonstrated a peak power-added efficiency (PAE) of 45.5% and a saturated output power density (${P}_{\text {sat}}$) of 8.5 W/mm at ${V}_{\text {ds}}= {30}$ V. In addition, the direct current (DC) and radio frequency (RF) characteristics showed a negligible degradation after large-signal measurements at 30 GHz. [ABSTRACT FROM AUTHOR]

In this article, the impact of the graded AlGaN back barrier and Fe\C co-doping buffer structure on the AlGaN $/$ GaN high electron mobility transistors (HEMTs) is proposed and systematically investigated. Due to effective suppression of Fe tail in unintentionally doped GaN (uid-GaN) layer by the insertion of the thick graded AlGaN back barrier layer, a large maximum drain current density and a transconductance peak are achieved. Meanwhile, the breakdown voltage is significantly improved by the use of Fe\C co-doping GaN buffer design. More importantly, it is revealed that the graded-AlGaN design can reduce the range and intensity of the electrical potential distribution in uid-GaN layer and then effectively suppress the acceptor-induced trapping\detrapping effect under high drain voltage. The RF small-signal performance of Fe-doped GaN (GaN:Fe)\C co-doping buffer HEMT exhibits significant improvement. In addition, load-pull measurement at 8 GHz revealed that a saturation power increases from 38.04 to 41.07 dB, a power gain increases from 9.06 to 10.58 dB, and an associate power-added-efficiency (PAE) increased from 40.27% to 50.18%. Our proposed GaN-based epitaxial structure can not only suppress the gate lag by reduce AlGaN surface electric field, but it can also suppress the drain lag by reduce the amplitude and range of potential distribution. It indicates that our proposed device has great potential for future high-voltage RF power amplifier application. [ABSTRACT FROM AUTHOR]

Ultra-wide bandgap semiconductor Ga2O3 based electronic devices are expected to perform beyond wide bandgap counterparts GaN and SiC. However, the reported power figure-of-merit hardly can exceed, which is far below the projected Ga2O3 material limit. Major obstacles are high breakdown voltage requires low doping material and PN junction termination, contradicting with low specific on-resistance and simultaneous achieving of n- and p-type doping, respectively. In this work, we demonstrate that Ga2O3 heterojunction PN diodes can overcome above challenges. By implementing the holes injection in the Ga2O3, bipolar transport can induce conductivity modulation and low resistance in a low doping Ga2O3 material. Therefore, breakdown voltage of 8.32 kV, specific on-resistance of 5.24 mΩ⋅cm2, power figure-of-merit of 13.2 GW/cm2, and turn-on voltage of 1.8 V are achieved. The power figure-of-merit value surpasses the 1-D unipolar limit of GaN and SiC. Those Ga2O3 power diodes demonstrate their great potential for next-generation power electronics applications. The simultaneous achievement of high breakdown voltage and low resistance is a contradictory point because it would require high and low doping simultaneously. Here, Zhou et al. achieve a power figure-of-merit of 13.2 GW/cm2 through hole injection and conductivity modulation effect. [ABSTRACT FROM AUTHOR]

In this Letter, a mechanism of current-collapse free for high-performance lateral AlGaN/GaN Schottky barrier diodes (SBDs) with a thick single-crystal GaN cap layer is investigated. A high breakdown voltage of 1.74 kV and a low specific on-resistance (RON,sp) of 5.04 mΩ cm2 are achieved for the fabricated SBD with a spatial distance (LAC) of 15 μm. Benefiting from the optimized groove anode technique, including a low-damaged etching process and a post-anode-annealing process, a low leakage current of 87 nA/mm at −500 V as well as a low turn-on voltage of 0.8 V defined at an anode current density of 1 mA/mm are obtained. Holes induced by polarization effects at the GaN/AlGaN interface inject to the anode edge at the ON state, and the negatively charged centers induced by a groove etching process are neutralized, which lead to the suppressed tunneling current (ITU) and idealized ideality factor (η). The forward current density decreases due to the suppressed ITU at the barrier-limited region. When the devices are biased at the OFF state, holes around cathodes inject to the buffer layer, which suppress hole emission at the buffer layer, and current collapse is greatly suppressed even after a 300-s-long bias test at −600 V. [ABSTRACT FROM AUTHOR]

In this work, we show that the $\beta $ -Ga2O3 Schottky Barrier Diode (SBD) can perform beyond the 1-D unipolar limit of the SiC and GaN by employing a deep trench with filled thick SiO2 layer structure to enhance the breakdown voltage (BV). By doing so, BV and specific on- resistance ($\text{R}_{\text {on},\text {sp}}$) of 5–6 kV and 3.4 $\text{m}\boldsymbol {\Omega } \cdot \text {cm}^{{2}}$ are simultaneously derived on the SBDs with $\beta $ -Ga2O3 epi-layer thickness of 10 $\boldsymbol {\mu } \text{m}$ and diode radius of 90 $\boldsymbol {\mu }\text{m}$. Therefore, the Baliga’s power figure of merit (P-FOM = BV $^{{2}} /\text{R}_{\text {on,sp}}$) is yielded to be 7.4-10.6 GW $/$ cm2. To the best of all authors’ knowledge, those P-FOMs are the highest values among all types of SBDs, which is a significant step towards the Ga2O3 SBD performance improvement. Combined with negligible forward hysteresis and low reverse leakage current, vertical $\beta $ -Ga2O3 SBDs with state-of-the-art BV and P-FOM show its great promise for next generation high voltage and high power applications. [ABSTRACT FROM AUTHOR]

In this Letter, we report on establishing high performance hysteresis-free and μs-switching depletion/enhancement-mode (D/E-mode) β-Ga2O3 heterojunction (HJ) field effect transistors (FETs) with the state-of-art power figure-of-merit (P-FOM). By optimizing the p-NiOx/n-Ga2O3 interface and n-Ga2O3 recess technology, a positive threshold voltage (VT) as well as a low subthreshold slope can be substantially achieved. The trade-off between the on-resistance (Ron,sp) and breakdown voltage (BV) is improved by incorporation of T-shaped NiOx, resulting in the Ron,sp of 6.24/13.75 mΩ cm2 and the breakdown voltage (BV) of 2145/1977 V for D/E-mode devices and yielding the P-FOM = BV2/Ron,sp to be 0.74/0.28 GW/cm2. To the best of all the authors' knowledge, those P-FOMs are the highest ones among all published lateral Ga2O3 FETs. Benefited from the high-quality interface, a negligible hysteresis of 4 mV and μs-switching can be essentially achieved, showing the great promise of Ga2O3 HJ-FETs for future high-power, high-efficiency, and high-speed power electronics. [ABSTRACT FROM AUTHOR]

In this work, ultrathin barrier (∼6 nm) AlGaN/GaN high-electron-mobility transistors (HEMTs) with in situ SiN gate dielectric and slant-field plate (SFP) T-gates were fabricated and analyzed. Since the proposed scheme of gate dielectric and SFP effectively suppresses the gate leakage and alleviates the peak electric field (E-field) around gate region, the maximum breakdown voltage (VBK) was improved to 92 V, which is 54 V higher than that of the conventional device. The fabricated ultrathin AlGaN/GaN HEMT with 60-nm SFP-T-gate exhibited the peak fT of 177 GHz and peak fmax of 393 GHz, yielding high figure-of-merits of fT · VBK = 16 THz V and fmax·VBK = 36 THz V. Moreover, load-pull measurements at 30 GHz reveal that these devices deliver output power density (Pout) of 4.6 W/mm at Vds = 20 V and high power-added efficiency up to 52.5% at Vds = 10 V. Essentially, the experimental results indicate that the employment of SFP and in situ SiN gate dielectric is an attractive approach to balance the breakdown and speed for millimeter wave devices. [ABSTRACT FROM AUTHOR]

DC performances of a depletion-mode 100-nm In0.53Ga0.47As/InP composite channel InP-based high-electron-mobility transistor (HEMT) is investigated by using numerical simulation. The transfer, output, and breakdown characteristics of different doped InP subchannel thickness In0.53Ga0.47As/InP composite channel HEMT are compared. Decreasing the thickness of the doped InP subchannel from 10 to 5 nm results in a decline of the output current. However, the threshold voltage is increased from −0.77 to −0.6 V and the breakdown voltage is improved from 1.99 to 5.69 V at bias of ${V}_{{\mathrm {gs}}}-{V}_{{\mathrm {t}}} = -0.5$ V. To enhance the breakdown characteristic of In0.53Ga0.47As/InP composite channel HEMT, we minimize the thickness of the doped InP layer and replace the doped InP layer with the delta-doped layer. The structure is compared with the conventional double delta-doped structure in the performance of transfer, output, and breakdown characteristics. At ON-state, the electrons of two kinds of structure concentrate in the InGaAs channel. The output current and the threshold voltage of the composite channel structure are at the same level compared with the conventional double delta-doped structure. However, at OFF-state, because of the transfer of electrons into the InP subchannel, part of electric potential will not be concentrated at the drain side of the gate region but distributed in other area of the channel. A higher drain voltage is required to achieve electric field strength enough to breakdown and the breakdown voltage is improved obviously. [ABSTRACT FROM AUTHOR]

In this work, $\beta $ -Ga2O3 MOSFETs grown by nonvacuum, cost-effective mist chemical vapor deposition (mist-CVD) method on Fe-doped GaN substrates were demonstrated for the first time. X-ray diffraction (XRD) and transmission electron microscopy (TEM) measurements identify the pure $\beta $ -Ga2O3 phase and the heteroepitaxial relationship with ($\bar {2}01$) $\beta $ -Ga2O3 $\|$ (0002) GaN. MOSFETs based on $\beta $ -Ga2O3 thin films with source–drain spacings (${L}_{\text{gd}}$) of 14 and $25 ~\mu \text{m}$ were fabricated and characterized. The destructive breakdown voltages (${V}_{\text{BR}}$) were measured to be 836 and 1420 V, respectively. The ON– OFF ratio of the corresponding MOSFETs was about five orders of magnitude. These results suggest the great application potential of the nonvacuum and cost-effective mist-CVD epitaxial growth method in $\beta $ -Ga2O3 MOSFETs, which will greatly decrease the device cost. [ABSTRACT FROM AUTHOR]

In this article, we report on demonstrating high-performance AlGaN/GaN high-electron-mobility-transistor (HEMT) on free-standing GaN (FS-GaN) substrate with low contact resistance (${R}_{C}$) and high breakdown voltage (BV). Non-regrowth ${R}_{C}$ as low as $0.23 \Omega \cdot $ mm was achieved by using the self-aligned Ohmic etching process and nonfield plated BV as high as 193 V was also acquired due to the low dislocation density of the epi-layer on FS-GaN substrate. It is found that the reduction of the ${R}_{C}$ is induced by the smaller electron tunneling width across the AlGaN barrier layer, rather than the formation of dislocation related metal spikes. The fabricated GaN HEMT was a peak extrinsic transconductance (${g}_{m}$) of 203 mS/mm and a drain current (${I}_{D}$) ON/OFF ratio of 106–107. Benefited from the low ${R}_{C}$ , a cut-off frequency/maximum oscillation frequency (${f}_{T}/{f}_{max}$) of 26/73 GHz was extracted at a gate length (${L}_{g}$) of 600 nm, yielding a ${f}_{T}\cdot {L}_{g}$ value of 15.6 GHz $\cdot \mu \text{m}$ and a Johnson’s figure-of-merit (J-FOM) of 5.0 THz $\cdot \text{V}$ , which are the highest values among all AlGaN/GaN HEMTs on FS-GaN substrate. This work implies that GaN HEMTs on FS-GaN substrate with low ${R}_{C}$ turn out to be a promising candidate for high-performance radio frequency (RF) power device applications. [ABSTRACT FROM AUTHOR]

This work acquires a vertical β-Ga2O3 Schottky barrier diode (SBD) with the advanced termination structure of p-type NiOx and n-type β-Ga2O3 heterojunctions and coupled field plate structures to alleviate the crowding electric field. A Ga2O3 SBD delivers an average breakdown voltage of 1860 V and a specific on-resistance of 3.12 mΩ cm2, yielding a state-of-the-art direct-current Baliga's power figure of merit of 1.11 GW/cm2 at an anode area of 2.83 × 10−5 cm2. In addition, the Ga2O3 SBD with the same fabrication process at a large area of 1.21 × 10−2 cm2 also presents a high forward current of 7.13 A, a breakdown voltage of 1260 V, and a power figure-of-merit of 235 MW/cm2. According to dynamic pulse switching and capacitance-frequency characteristics, an optimized p-NiOx/Ga2O3 interface with a maximum trap density of 4.13 × 1010 eV−1 cm−2 is delivered. Moreover, based on the forward current-voltage measurement at various temperatures, the physics behind a forward conduction mechanism is illustrated. Ga2O3 SBDs with p-NiOx/n-Ga2O3 heterojunction termination, field plate, high power figure of merit, and high quality interface as well as suppressed resistance increase after dynamic pulse switching, verifying their great promise for future high power applications. [ABSTRACT FROM AUTHOR]

The vertical heterojunction Ga2O3 MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) with the p-type oxide as the current-blocking layer (CBL) is investigated for the first time using SILVACO simulation software. The results show that the threshold voltage of the device is easily positive, which means that the device works in the enhancement mode. By adjusting the doping concentration (from 2 × 1017 cm−3 to 2 × 1018 cm−3) and thickness (from 0.4 um to 2 um) of p-SnO CBL, the threshold voltage is around from 2.4 V to 2.8 V and the breakdown voltage of the device can be increased from 361 V to 518 V. Compared with the original homojunction Ga2O3 vertical MOSFET with CBL, the p-SnO CBL can greatly improve the performance of the device. Other p-type oxides are also investigated as the CBL and show promising performances. This work has a certain guiding significance for the design of a vertical enhanced current-blocking layer MOSFET device and for the development of a Ga2O3 heterojunction power device. [ABSTRACT FROM AUTHOR]

This work reports recent progress in the sub-6 GHz power performance of GaN-based HEMTs grown on high resistivity silicon substrates with passivation implanted termination (PIT) process. Thanks to the mitigated electric field crowding at the gate edge and the suppressed negative fixed charge-induced carrier depletion, the fabricated HEMTs demonstrate a low leakage current, a high ON/OFF current ratio of 108, and improved breakdown voltage associated with a current collapse at 40 V drain quiescent condition of as low as 5.6%. S-band continuous-wave large signal measurements yield a high power-added efficiency (PAE) of 69%, a drain efficiency (DE) of 72%, and an output power density (${P}_{\text{out}}$) of 7.2 W/mm at ${V}_{\text{DS}}=30$ V. Moreover, the transistor delivers a maximum ${P}_{\text{out}}$ up to 10.2 W/mm with a peak PAE of 63.8% at ${V}_{\text{DS}}=40$ V. The PAE and ${P}_{\text{out}}$ as a function of drain bias indicate that the transistors remain constant high PAE and linearly increased ${P}_{\text{out}}$ over a wide range of drain voltage variation. These excellent results have demonstrated the PIT process could be an attractive technique to facilitate the application of high-performance and cost-competitive GaN-on-Si HEMTs for 5G wireless base stations. [ABSTRACT FROM AUTHOR]

AlGaN/GaN lateral Schottky barrier diodes (SBDs) with the nonrecessed and recessed floating metal rings (FMR) structure are fabricated and electrically characterized to study the influence of recessed FMR structure. The recessed FMR SBDs (RFMR‐SBDs) exhibit the lower onset voltage (VON) and higher forward current (IF) at the anode of 3 V than the nonrecessed FMR SBDs (FMR‐SBDs). More importantly, the breakdown voltage (VBR) of the RFMR‐SBDs is 1980 V, which has a significant improvement compared with the FMR‐SBDs of 1540 V. However, the specific on‐resistance of the RFMR‐SBDs is higher than FMR‐SBDs. Furthermore, the electric field distributions of different structures are simulated by Silvaco software to analyze the mechanism of improving breakdown voltage. The results show that the breakdown voltage improvement is due to the broader depletion region in the RFMR‐SBDs at the breakdown voltage. Moreover, the electric field distributions of the RFMR‐SBDs and FMR‐SBDs with three FMRs are discussed further. [ABSTRACT FROM AUTHOR]

A GaN complementary field-effect transistor (FET) inverter monolithically integrated with power gate-injection high-electron-mobility transistors (HEMTs) was realized on a Si substrate. The GaN p-channel and n-channel logic devices and power devices were fabricated based on a p-GaN/AlGaN/GaN epi-structure. Through optimization of epi-layer thickness and doping, excellent low-level noise margin (NML) of 1.47 V and high-level noise margin (NMH) of 0.98 V were achieved at a supply voltage ${V}_{\text {DD}}$ of 3 V at room temperature. A maximum current density (${I}_{\text {D,max}}$) of 0.36 mA/mm/220 mA/mm at ${V}_{\text {DS}}$ of −3 V/3 V and a threshold voltage ${V}_{\text {TH}}$ of −2.0 V/+2.3 V were achieved in the p-channel and n-channel FETs, respectively. A propagation delay of an inverter stage $\tau _{\text {pd}}$ in a ring oscillator was measured to be $1.67~\mu \text{s}$. The power gate-injection HEMT has an ON-resistance ${R}_{ \mathrm{\scriptscriptstyle ON}}$ of $18.7~\Omega \cdot $ mm and a breakdown voltage (BV) of 900 V. These results show the great potential of the developed GaN complementary FET technology in the applications of GaN power modules. [ABSTRACT FROM AUTHOR]

In this Letter, an ultra-thin AlGaN/GaN heterostructure field effect transistor (HFET) with a total thickness of ∼200 nm was fabricated on sapphire substrates by combing physical vapor deposition and metal organic chemical vapor deposition growth methods. Thanks to the absence of a conventional semi-insulating thick GaN buffer by taking advantage of an ex situ sputtered AlN nucleation layer, we achieved a profound soft breakdown voltage of 1700 V accompanied by a 12.5 Ω·mm on-resistance and a low off-state leakage of 0.1 μA/mm in such ultra-thin HFET devices. Our work demonstrates an alternative strategy to fabricate GaN based power devices with high breakdown voltage and low cost. [ABSTRACT FROM AUTHOR]

A lateral Schottky barrier diode (SBD) on p-GaN/AlGaN/GaN heterostructure with arrayed p-GaN islands termination (API-SBD) is proposed and investigated in this work. On the basis of the unique design approach, API-SBD presents a reduced reverse leakage current (${I}_{R}$) with one order of magnitude lower than that of counterpart SBD with the only recessed anode (R-SBD). The turn-on voltage (${V}_{ \mathrm{\scriptscriptstyle ON}}$) of API-SBD is nearly the same as that of R-SBD, which shows an effective improvement of the tradeoff between ${V}_{ \mathrm{\scriptscriptstyle ON}}$ and ${I}_{R}$. The breakdown voltage (BV) of API-SBD is obviously improved due to the introduction of p-GaN islands termination by shielding the high electric field from the Schottky junction. In addition, the capacitance of API-SBD is approximately a half of that of R-SBD. The fabricated API-SBD with a 15- $\mu \text{m}$ anode–cathode distance exhibits a ${V}_{ \mathrm{\scriptscriptstyle ON}}$ of ~0.59 V, an ${I}_{R}$ of ~10 nA/mm (at −100 V), and a BV of 1070 V (at ${1}~\mu \text{A}$ /mm). It is worth noting that the fabrication process of API-SBD is fully compatible with that of p-GaN HEMT, which is helpful for the monolithic integration. [ABSTRACT FROM AUTHOR]

In this work, a novel reverse blocking Schottky-drain Si–GaN monolithic integrated cascode FET was realized for the first time by using transfer printing and self-aligned etching technology. The threshold voltage is up to 4.5 V, which meets the needs of the power electronic system. The on-resistance is 57.1 Ω mm, and the on-voltage is 1.1 V. The forward/reverse breakdown voltage (at 10 µA/mm) reaches 1325/−1240 V for LGD = 18 µm. The mechanism of reverse blocking is proposed and analyzed from the point of view of circuits. In addition, the correctness of the mechanism is verified by simulation and experiment. [ABSTRACT FROM AUTHOR]

A low temperature controlled annealing technique was utilized to improve the performance of vertical β-gallium oxide (β-Ga2O3) Schottky barrier diodes (SBDs) in this work. The nickel is diffused into Ga2O3, and NiO was formed at the interface between the anode and semiconductor generating p–n junction after low temperature annealing. Simultaneously, the trap state density of interface Ni/Ga2O3 as well as the carbon bonded with oxygen on the surface was reduced, which was proved by the capacitance and conductance measurements and x-ray photoelectron spectroscopic analysis, respectively. Combined the decreased saturation current density by three orders of magnitude from 1.21 × 10−6 to 9.27 × 10−8 and 5.12 × 10−9 A/cm2 and larger breakdown voltage from 220 to 270 V owing to the optimized interface and the formation of NiO, a low temperature annealing technique makes certain effective improvement for vertical β-Ga2O3 SBDs via interface engineering. [ABSTRACT FROM AUTHOR]

In this article, the Au-free complementary metal oxide semiconductor (CMOS) transistor compatible AlGaN-channel high-electron-mobility transistors (HEMTs) on silicon substrate with 2-kV forward and reverse blocking voltages have been reported. Due to the designed AlGaN epitaxial layers, breakdown voltages (BVs) of the conventional AlGaN-channel HEMTs with $L_{GD} =5$ /10/15/ 20/ $25~\mu \text{m}$ are 420/1070/1590/1920/2000 V respectively, and the values are increased to 760/1420/1980/1990/2000 V by using Schottky-drain technique. The reverse-blocking HEMTs demonstrate reverse blocking voltages of −790/−1300/−1810/−2000 V for ${L}_{GD}=5$ /10/15/ $20~\mu \text{m}$. Meanwhile, the conventional HEMT power figure-of-merit (FOM) of 397 MW/cm2 is the highest FOM for AlGaN-channel HEMTs on silicon, and the Schottky-drain HEMT forward FOM of 384 MW/cm2 and reverse FOM of 321 MW/cm2 are the highest FOM values for all GaN-based reverse-blocking HEMTs on silicon. [ABSTRACT FROM AUTHOR]

A monolithic bidirectional switch based on anti-paralleled two reverse blocking p-GaN HEMTs has been proposed and demonstrated in this work. The recessed Schottky drain technique is utilized to effectively reduce the on-state voltage and thus lowering the power loss of bidirectional switches. A significant reduction in parasitic elements and switch area is obtained by monolithic integration. The fabricated bidirectional switch exhibits a threshold voltage of ~1.85 V, on-state voltage of ~0.63 V, and the forward and reverse off-state breakdown voltages of ~650 V at IS1−S2 = 1 μA/mm. In addition, the function of proposed bidirectional switch as an AC power chopper has been successfully verified. [ABSTRACT FROM AUTHOR]

In this Letter, the p-GaN high electron mobility transistor (HEMT) with hybrid drain of recessed Schottky (RS) and p-GaN isolation blocks' drain (HSP drain) is proposed and fabricated for good reverse blocking capability. The related operation mechanism has been investigated and revealed. The proposed device features a drain terminal consisting of the array-distributed recessed Schottky and p-GaN isolation blocks. Based on the features, the reverse leakage current (5 × 10−9 A/mm at VDS = −100 V) is obviously reduced by two orders of magnitude compared with that (5 × 10−7 A/mm) of p-GaN HEMTs only with recessed Schottky (RS) drain, which is the lowest leakage current among the reported GaN-on-Si reverse blocking transistors. The introduction of these p-GaN isolation blocks has a negligible impact on Von (Von = 0.63 V). Therefore, a good improvement in the trade-off between the reverse leakage current and Von could be achieved because of the significant reduction in the reverse leakage current without sacrificing Von. In addition, the reverse breakdown voltage of −800 V at 1 μA/mm with a substrate grounded in the proposed device is evidently improved compared with the counterpart (−680 V), which is attributed to effective alleviation of the high electric field near the HSP drain. These results demonstrate the significance and potential of p-GaN HEMTs with HSP drain in reverse blocking applications. [ABSTRACT FROM AUTHOR]

High-electron-mobility transistor (HEMT) with AlN/GaN superlattice (SL) channel has been demonstrated on a silicon substrate. High OFF-state breakdown voltage VBR of 670 V (gate–drain spacing LGD = 8 μm) along with a maximum output current of 196 mA/mm, a channel electron total mobility of 507 cm2/ V⋅ s , and an ON/ OFF ratio of over 107 was achieved in this novel HEMT. For the HEMT with LGD = 22 μm , a high VBR of 1700 V was obtained with substrate floated. The influence of LGD , the gate–source voltage VGS , the isolated pattern, and substrate grounded and floated type was discussed to analyze the breakdown characteristics of HEMT. We investigated the trap states in the AlN/GaN SL channel of HEMTs by frequency-dependent capacitance and conductance measurements. A trap state density of 7.4× 1012 – 1.2× 1013 cm−2eV−1 is located at ET in a range of 0.29–0.33 eV of the main channel, while the trap state density in the parasitic channel decreases from 3.9× 1011 cm−2eV−1 at an energy of 0.27 eV to 1.1× 1011 cm−2eV−1 at an energy of 0.38 eV. The fabricated AlN/GaN SL channel HEMTs in this work reveal a great step toward the realization of the SL channel HEMTs on cost-effective silicon substrate and provide a novel technology for AlGaN multichannel devices to obtain high output current. [ABSTRACT FROM AUTHOR]

In this work, we report on demonstrating lateral β-Ga2O3 Schottky barrier diodes (SBDs) fabricated on Fe-GaN/sapphire (0001) substrates by using the non-vacuum, low-cost mist chemical vapor deposition (mist CVD) method for the first time. The x-ray diffraction scanning pattern identifies that β-Ga2O3 layers are grown with (−201) planes parallel to the (0001) plane of the GaN template, and the transmission electron microscopy shows that the β-Ga2O3 lattice is regularly and neatly arranged, indicating good crystal quality. β-Ga2O3 based SBDs with 4 and 20 µm anode–cathode lengths (LAC) exhibit the specific on-resistance (Ron,sp) of 1.58 and 39.8 Ω cm2 and breakdown voltage (Vbr) of 580 and 2400 V, respectively. The present results show the great potential of the non-vacuum and cost-effective mist CVD method as the epitaxial growth technique employed in β-Ga2O3 devices. [ABSTRACT FROM AUTHOR]