Wide Bandgap Semiconductor Electronics and Devices

Topic Information

Dear Colleagues,

Wide bandgap (WBG) semiconductors, such as silicon carbide (SiC), gallium nitride (GaN), and emerging materials like gallium oxide (Ga₂O₃) and diamond, have revolutionized the fields of electronics and optoelectronics due to their superior electrical, thermal, and optical properties. Their high breakdown voltage, low on-resistance, and excellent thermal conductivity make them ideal for power electronics, enabling energy-efficient devices with enhanced performance and miniaturization. In optoelectronics, WBG materials support high-power light-emitting diodes (LEDs), laser diodes, and ultraviolet photodetectors, expanding applications in lighting, communication, and sensing. Additionally, the ability of WBG semiconductors to operate at higher temperatures and frequencies than conventional silicon-based materials makes them critical for advanced RF and microwave systems. Recent advancements in material synthesis, defect engineering, and device fabrication techniques have significantly improved the performance and reliability of WBG-based devices. However, challenges remain in cost-effective large-scale production, material quality, long-term reliability, and interface engineering, which hinder widespread adoption. This issue explores the latest developments in WBG semiconductor materials, device architectures, and emerging applications, highlighting the potential breakthroughs in high-power electronics, high-frequency communication, and next-generation optoelectronic systems. Addressing current limitations will pave the way for the next generation of energy-efficient and high-performance electronic and optoelectronic devices.

Prof. Dr. Joseph Bernstein
Dr. Asaf Albo
Topic Editors

Keywords

Participating Journals

Journal Name	Impact Factor	CiteScore	Launched Year	First Decision (median)	APC
Electronics electronics	2.6	6.1	2012	16.8 Days	CHF 2400	Submit
Eng eng	2.4	3.2	2020	19.7 Days	CHF 1400	Submit
Materials materials	3.2	6.4	2008	15.2 Days	CHF 2600	Submit
Micro micro	1.9	3.2	2021	28.1 Days	CHF 1200	Submit
Micromachines micromachines	3.0	6.0	2010	17.2 Days	CHF 2100	Submit

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Published Papers (8 papers)

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23 pages, 3955 KB  

Open AccessReview

The ESD Robustness and Protection Technology of P-GaN HEMT

by Yijun Shi, Yantao Chen, Liang He, Xinghuan Chen, Yuan Chen and Guoguang Lu

Micromachines 2025, 16(11), 1269; https://doi.org/10.3390/mi16111269 - 11 Nov 2025

Viewed by 255

Abstract

This work first analyzes the failure behaviors of P-GaN HEMTs with different gate structures (Schottky gate vs. Ohmic gate) under both forward and reverse ESD stresses. It reveals that the Schottky gate structure lacks effective electrostatic charge discharge paths, which leads to the [...] Read more.

This work first analyzes the failure behaviors of P-GaN HEMTs with different gate structures (Schottky gate vs. Ohmic gate) under both forward and reverse ESD stresses. It reveals that the Schottky gate structure lacks effective electrostatic charge discharge paths, which leads to the accumulation of transient charges generated by ESD stress in the gate terminal, resulting in significant transient overvoltage and ultimately causing breakdown failure. Subsequently, the paper systematically reviews three existing unidirectional ESD protection technologies based on the P-GaN HEMT platform. While these technologies can discharge transient electrostatic charges generated by both forward and reverse ESD stresses, they operate in diode mode during reverse ESD events, exhibiting excessively low reverse triggering voltage. Furthermore, unidirectional ESD protection structures based on resistive voltage division and diode voltage division introduce substantial forward and reverse leakage currents. Finally, the article evaluates four bidirectional GaN ESD protection technologies. These bidirectional structures can likewise discharge transient charges from both forward and reverse ESD stresses. Compared to unidirectional approaches, the key advantage of bidirectional ESD protection lies in its ability to provide an appropriate reverse triggering voltage during reverse ESD events, thereby effectively clamping the reverse potential to the desired level. However, likewise, bidirectional ESD protection schemes based on resistive or diode voltage division also inevitably introduce relatively large forward and reverse leakage currents. Full article

(This article belongs to the Topic Wide Bandgap Semiconductor Electronics and Devices)

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19 pages, 3047 KB  

Open AccessArticle

Thermal Management of Wide-Bandgap Power Semiconductors: Strategies and Challenges in SiC and GaN Power Devices

by Gyuyeon Han, Junseok Kim, Sanghyun Park and Wongyu Bae

Electronics 2025, 14(21), 4193; https://doi.org/10.3390/electronics14214193 - 27 Oct 2025

Viewed by 1612

Abstract

Wide-Bandgap (WBG) semiconductors—silicon carbide (SiC) and gallium nitride (GaN)— enable high-power-density conversion, but performance is limited by where heat is generated and how it is removed. This review links device-level loss mechanisms (conduction and switching, including output-capacitance hysteresis and dynamic on-resistance) to structure-driven [...] Read more.

Wide-Bandgap (WBG) semiconductors—silicon carbide (SiC) and gallium nitride (GaN)— enable high-power-density conversion, but performance is limited by where heat is generated and how it is removed. This review links device-level loss mechanisms (conduction and switching, including output-capacitance hysteresis and dynamic on-resistance) to structure-driven hot spots within the ultra-thin (tens of nanometers) two-dimensional electron gas (2DEG) channel of GaN HEMTs and to thermal boundary resistance at layer interfaces. We compare wire-bondless package concepts—double-sided cooling, embedded packaging, and interleaved planar layouts—and survey system-level cooling that shortens the conduction path and raises heat-transfer coefficients. The impact on reliability is discussed using temperature-sensitive electrical parameters (e.g., on-state VDS, threshold voltage, drain leakage, di/dt, and gate current) for real-time junction-temperature estimation and compact electro-thermal RC models for remaining-useful-life prediction. Evidence from recent literature points to interface resistance in GaN-on-SiC as a primary bottleneck, while near-junction cooling and advanced packages are effective mitigations. We argue for integrated co-design—devices, packaging, electromagnetic interference (EMI)-aware layout, and cooling—together with interface engineering and health monitoring to deliver reliable, high-density WBG systems. Full article

(This article belongs to the Topic Wide Bandgap Semiconductor Electronics and Devices)

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13 pages, 3651 KB  

Open AccessArticle

Optical Absorption Properties of Sn- and Pd-doped ZnO: Comparative Analysis of Substitutional Metallic Impurities

by Vicente Cisternas, Pablo Díaz, Ulises Guevara, David Laroze and Eduardo Cisternas

Materials 2025, 18(19), 4613; https://doi.org/10.3390/ma18194613 - 5 Oct 2025

Viewed by 515

Abstract

In this article, we present density functional theory (DFT) calculations for $Z{n}_{(1-x)}{M}_{x}O$, where M represents one of the following substitutional metallic impurities: Ga, Cd, Cu, Pd, Ag, In, or Sn. Our study is [...] Read more.

In this article, we present density functional theory (DFT) calculations for $Z{n}_{(1-x)}{M}_{x}O$, where M represents one of the following substitutional metallic impurities: Ga, Cd, Cu, Pd, Ag, In, or Sn. Our study is based on the wurtzite structure of pristine ZnO. We employ the Quantum Espresso package, using a fully unconstrained implementation of the generalized gradient approximation (GGA) with an additional U correction for exchange and correlation effects. We analyze the density of states, energy gaps, and absorption spectra for these doped systems, considering the limitations of a finite-size cell approximation. Rather than focusing on precise numerical values, we highlight the following two key aspects: the location of impurity-induced electronic states and the overall trends in optical properties across the eight systems, including pristine ZnO. Our results indicate that certain dopants introduce electronic levels within the band gap, which enhance optical absorption in the visible, near-infrared, and near-ultraviolet regions. For instance, Sn-doped ZnO shows a pronounced absorption peak at ∼2.5 eV, which is in the middle of the visible spectrum. In the case of Ag and Pd impurities, they lead to increased electromagnetic radiation absorption at the near ultra-violet spectrum. This represents a promising performance for efficient solar radiation absorption, both at the Earth’s surface and in outer space. Furthermore, Ga- and In-doped ZnO present bandgaps of ∼0.9 eV, promising an interesting performance in the near infrared region. These findings suggest potential applications in solar energy harvesting and selective sensors. Full article

(This article belongs to the Topic Wide Bandgap Semiconductor Electronics and Devices)

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27 pages, 7591 KB  

Open AccessArticle

Switching Frequency Figure of Merit for GaN FETs in Converter-on-Chip Power Conversion

by Liron Cohen, Joseph B. Bernstein, Roni Zakay, Aaron Shmaryahu and Ilan Aharon

Electronics 2025, 14(19), 3909; https://doi.org/10.3390/electronics14193909 - 30 Sep 2025

Cited by 1 | Viewed by 825

Abstract

Power converters are increasingly pushing toward higher switching frequencies, with current designs typically operating between tens of kilohertz and a few megahertz. The commercialization of gallium nitride (GaN) power transistors has opened new possibilities, offering performance far beyond the limitations of conventional silicon [...] Read more.

Power converters are increasingly pushing toward higher switching frequencies, with current designs typically operating between tens of kilohertz and a few megahertz. The commercialization of gallium nitride (GaN) power transistors has opened new possibilities, offering performance far beyond the limitations of conventional silicon devices. Despite this promise, the potential of GaN technology remains underutilized. This paper explores the feasibility of achieving sub-gigahertz switching frequencies using GaN-based switch-mode power converters, a regime currently inaccessible to silicon-based counterparts. To reach such operating speeds, it is essential to understand and quantify the intrinsic frequency limitations imposed by GaN device physics and associated parasitics. Existing power conversion topologies and control techniques are unsuitable at these frequencies due to excessive switching losses and inadequate drive capability. This work presents a detailed, systematic study of GaN transistor behavior at high frequencies, aiming to identify both fundamental and practical switching limits. A compact analytical model is developed to estimate the maximum soft-switching frequency, considering only intrinsic device parameters. Under idealized converter conditions, this upper bound is derived as a function of internal losses and the system’s target efficiency. From this, a soft-switching figure of merit is proposed to guide the design and layout of GaN field-effect transistors for highly integrated power systems. The key contribution of this study lies in its analytical insight into the performance boundaries of GaN transistors, highlighting the roles of parasitic elements and loss mechanisms. These findings provide a foundation for developing next-generation, high-frequency, chip-scale power converters. Full article

(This article belongs to the Topic Wide Bandgap Semiconductor Electronics and Devices)

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14 pages, 2205 KB  

Open AccessArticle

Optimization of Thermal Stress in High-Power Semiconductor Laser Array Packaging

by Lei Cheng, Bingxing Wei, Xuanjun Dai, Yanan Bao and Huaqing Sun

Electronics 2025, 14(16), 3336; https://doi.org/10.3390/electronics14163336 - 21 Aug 2025

Viewed by 899

Abstract

To suppress the thermal stress in high-power semiconductor laser array packaging, the classic asymmetric heat dissipation structure of the array packaging was transformed into a symmetric one by incorporating microchannel heat sinks. This effectively reduced the maximum temperature, maximum thermal stress, thermal resistance, [...] Read more.

To suppress the thermal stress in high-power semiconductor laser array packaging, the classic asymmetric heat dissipation structure of the array packaging was transformed into a symmetric one by incorporating microchannel heat sinks. This effectively reduced the maximum temperature, maximum thermal stress, thermal resistance, and maximum vertical displacement of the semiconductor laser array. Using the response surface methodology, mathematical models were established to correlate the maximum temperature, maximum thermal stress, and maximum vertical displacement of the semiconductor laser array with the radius, height, and spacing of circular micro-pin fins. A genetic algorithm was then employed to perform multi-objective optimization of these parameters. The results demonstrate that, compared to the original packaging configuration, the optimized semiconductor laser array exhibits a maximum temperature reduction of 16.56 °C, a maximum thermal stress decrease of 24.01 MPa, and a reduction in the maximum vertical displacement of the chip by 0.77 μm. Full article

(This article belongs to the Topic Wide Bandgap Semiconductor Electronics and Devices)

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17 pages, 2806 KB  

Open AccessArticle

Impact of Multi-Bias on the Performance of 150 nm GaN HEMT for High-Frequency Applications

by Mohammad Abdul Alim and Christophe Gaquiere

Micromachines 2025, 16(8), 932; https://doi.org/10.3390/mi16080932 - 13 Aug 2025

Viewed by 862

Abstract

This study examines the performance of a GaN HEMT with a 150 nm gate length, fabricated on silicon carbide, across various operational modes, including direct current (DC), radio frequency (RF), and small-signal parameters. The evaluation of DC, RF, and small-signal performance under diverse [...] Read more.

This study examines the performance of a GaN HEMT with a 150 nm gate length, fabricated on silicon carbide, across various operational modes, including direct current (DC), radio frequency (RF), and small-signal parameters. The evaluation of DC, RF, and small-signal performance under diverse bias conditions remains a relatively unexplored area of study for this specific technology. The DC characteristics revealed relatively little I_ds at zero gate and drain voltages, and the current grew as V_gs increased. Essential measurements include I_dss at 109 mA and I_dssm at 26 mA, while the peak g_m was 62 mS. Because transconductance is sensitive to variations in V_gs and V_ds, it shows “Vth _roll-off,” where Vth decreases as V_ds increases. The transfer characteristics corroborated this trend, illustrating the impact of drain-induced barrier lowering (DIBL) on threshold voltage (Vth) values, which spanned from −5.06 V to −5.71 V across varying drain-source voltages (V_ds). The equivalent-circuit technique revealed substantial non-linear behaviors in capacitances such as C_gs and C_gd concerning V_gs and V_ds, while also identifying extrinsic factors including parasitic capacitances and resistances. Series resistances (R_gs and R_gd) decreased as V_gs increased, thereby enhancing device conductivity. As V_gs approached neutrality, particularly at elevated V_ds levels, the intrinsic transconductance (g_mo) and time constants (τ_gm, τ_gs, and τ_gd) exhibited enhanced performance. f_t and f_max, which are essential for high-frequency applications, rose with decreasing V_gs and increasing V_ds. When V_gs approached −3 V, the S₂₁ and Y₂₁ readings demonstrated improved signal transmission, with peak S₂₁ values of approximately 11.2 dB. The stability factor (K), which increased with V_ds, highlighted the device’s operational limits. The robust correlation between simulation and experimental data validated the equivalent-circuit model, which is essential for enhancing design and creating RF circuits. Further examination of bias conditions would enhance understanding of the device’s performance. Full article

(This article belongs to the Topic Wide Bandgap Semiconductor Electronics and Devices)

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9 pages, 1789 KB  

Open AccessCommunication

Near-Field Imaging of Hybrid Surface Plasmon-Phonon Polaritons on n-GaN Semiconductor

by Vytautas Janonis, Adrian Cernescu, Pawel Prystawko, Regimantas Januškevičius, Simonas Indrišiūnas and Irmantas Kašalynas

Materials 2025, 18(12), 2849; https://doi.org/10.3390/ma18122849 - 17 Jun 2025

Viewed by 836

Abstract

Near-field imaging of the hybrid surface plasmon-phonon polaritons on the n-GaN semiconductor was performed using a scattering scanning near-field optical microscope at the selected frequencies of 920 cm⁻¹ and 570 cm⁻¹. The experimental measurements and numerical modeling data were in [...] Read more.

Near-field imaging of the hybrid surface plasmon-phonon polaritons on the n-GaN semiconductor was performed using a scattering scanning near-field optical microscope at the selected frequencies of 920 cm⁻¹ and 570 cm⁻¹. The experimental measurements and numerical modeling data were in good agreement, revealing the large propagation distances on the n-GaN semiconductor and other insights which could be obtained by analyzing the dispersion characteristics of hybrid polaritons. In particular, the decay lengths of polaritons at the excitation frequency of 920 cm⁻¹ were measured to be up to 25 and 30 µm in experiment and theory, respectively. In the case of excitation at the frequency of 570 cm⁻¹, the surface plasmon-phonon polaritons’ decay distances were 25 µm and 105 µm, respectively, noting the limitations of the near-field optical microscope setups used. Dispersion characteristics of the resonant frequency and the damping rate of hybrid polaritons were numerically modeled and compared with the analytical calculations, validating the need for further experiment improvements. The launch conditions for the near-field observation of extraordinary coherence of the surface plasmon-phonon polaritons were also discussed. Full article

(This article belongs to the Topic Wide Bandgap Semiconductor Electronics and Devices)

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14 pages, 4015 KB  

Open AccessArticle

Effect of Dual Al₂O₃ MIS Gate Structure on DC and RF Characteristics of Enhancement-Mode GaN HEMT

by Yuan Li, Yong Huang, Jing Li, Huiqing Sun and Zhiyou Guo

Micromachines 2025, 16(6), 687; https://doi.org/10.3390/mi16060687 - 7 Jun 2025

Viewed by 1267

Abstract

A dual Al₂O₃ MIS gate structure is proposed to enhance the DC and RF performance of enhancement-mode GaN high-electron mobility transistors (HEMTs). As a result, the proposed MOS-HEMT with a dual recessed MIS gate structure offers 84% improvements in cutoff [...] Read more.

A dual Al₂O₃ MIS gate structure is proposed to enhance the DC and RF performance of enhancement-mode GaN high-electron mobility transistors (HEMTs). As a result, the proposed MOS-HEMT with a dual recessed MIS gate structure offers 84% improvements in cutoff frequency (f_T) and 92% improvements in maximum oscillation frequency (f_max) compared to conventional HEMTs (from 7.1 GHz to 13.1 GHz and 17.5 GHz to 33.6 GHz, respectively). As for direct-current characteristics, a remarkable reduction in off-state gate leakage current and a 26% enhancement in the maximum saturation drain current (from 519 mA·mm⁻¹ to 658 A·mm⁻¹) are manifested in HEMTs with new structures. The maximum transconductance (g_m) is also raised from 209 mS·mm⁻¹ to 246 mS·mm⁻¹. Correspondingly, almost unchanged gate–source capacitance curves and gate–drain capacitance curves are also discussed to explain the electrical characteristic mechanism. These results indicate the superiority of using a dual Al₂O₃ MIS gate structure in GaN-based HEMTs to promote the RF and DC performance, providing a reference for further development in a miniwatt antenna amplifier and sub-6G frequencies of operation. Full article

(This article belongs to the Topic Wide Bandgap Semiconductor Electronics and Devices)

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