【Specialist Intro】Zhang Xiaodong —— the Member of Technical Expert Committee

Personal Profile

      Zhang Xiaodong, Researcher and Doctoral Supervisor at the Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences. He has long been engaged in research on semiconductor materials, devices, and fabrication processes, focusing on ultra-wide-bandgap semiconductors such as Gallium Oxide (Ga₂O₃), Aluminum Nitride (AlN), and hexagonal boron nitride (h-BN). His work covers MOCVD epitaxial growth, power and optoelectronic devices, and heterogeneous integration technologies. In recent years, he has led multiple national and provincial-level research projects, published over 80 SCI papers in leading international journals, and filed more than 40 domestic and international patents. He has been recognized with numerous honors, including National Model Worker, the National May Day Labor Medal, and the CAS Technology Support Talent Award.

Research Achievements

      1.MOCVD Epitaxial Growth of Ga₂O₃ Thin Films
      Prof. Zhang’s team investigated the growth dynamics of Ga₂O₃ heteroepitaxy and achieved high-quality epitaxial films on silicon and sapphire substrates. By introducing AlN and molybdenum (Mo) interlayers, they effectively reduced the lattice mismatch between Si and Ga₂O₃ and prevented substrate oxidation during epitaxy, thereby improving film crystallinity and suppressing defect formation.
The resulting Ga₂O₃ films on Si substrates achieved world-leading performance.
Additionally, by employing indium (In) as a surfactant, they promoted lateral coalescence of the film and solved trench-like surface morphology issues.
This led to the first reported MOCVD-grown high-quality homoepitaxial (001) β-Ga₂O₃ film, laying the material foundation for large-area (001)-oriented β-Ga₂O₃ development.

      References:

      [1] Y Hu, et al. Effects of growth temperature on phase transformation and crystal quality of Ga₂O₃ films grown on Si/AlN composite substrates by MOCVD [J]. Materials Science in Semiconductor Processing, 2024, 178, 108453.

      [2] Y Hu, et al. High-performance Ga₂O₃ solar-blind ultraviolet photodectors on Si (100) substrate with molybdenum buffer layer [J]. Vacuum, 2023, 213, 112130. 

      [3] WB Tang, et al. High-Quality (001) β-Ga₂O₃ Homoepitaxial Growth by MOCVD Enabled by In-Situ Indium Surfactant [J]. Applied Physics Letters, 2022, 120, 212103, 1-7.

      2.Ga₂O₃ Solar-Blind Ultraviolet Detectors and Integration
      Using in situ grown Ga₂O₃ single-crystal nanoparticles, the team fabricated high-speed, high-sensitivity solar-blind UV detector arrays, and successfully demonstrated UV imaging and display, opening new directions for photodetection applications. The in situ Ga₂O₃ nanoparticles effectively modulated the film growth mode, reduced dislocations and defects, and mitigated self-trapped hole generation. Under 254 nm illumination, the detector achieved a −3 dB bandwidth exceeding 2 kHz, a decay time of only 62 μs, a specific detectivity >10¹⁴ Jones, and a responsivity of 4.2×10⁴ mA/W. The device also exhibited excellent linearity, with a dynamic range of 61 dB and an ultra-low noise current of 5.23×10⁻³ pA·Hz⁻¹/².

      References:
      [1] TW Chen, et al. Ultrasensitive dynamic ultraviolet imaging based on a Ga₂O₃ photodetector array [J]. Optics Letters, 2025, 50(5): 1633-1636.

      [2] HY Zhang, et al. High-Speed and High-Responsivity Quasi-Vertical Schottky Photodetectors of Epitaxial Ga₂O₃ on Pt Substrate [J]. IEEE Electron Device Letters, 2025, 46(1): 60-63.

      [3] TW Chen, et al. High-Speed and Ultrasensitive Solar-Blind Ultraviolet Photodetectors Based on In Situ Grown β-Ga₂O₃ Single-Crystal Films [J]. ACS Applied Materials & Interfaces, 2024, 16(5): 6068-6077.

      3.Ga₂O₃ Power Electronic Devices and Fabrication Processes
      The team developed a β-Ga₂O₃ U-shaped trench gate MOSFET incorporating N-ion-implanted current-blocking layers with optimized implantation concentrations and activation annealing temperatures. Without a field plate, the U-MOSFET achieved a breakdown voltage of 1.3 kV, demonstrating the strong potential of N-ion implantation for high-performance β-Ga₂O₃ UMOSFETs. They also fabricated multi-fin-channel diodes (MFCDs) with ohmic-contact anodes. By leveraging the self-depletion effect induced by submicron fin structures, they effectively suppressed leakage current under high electric fields, achieving a breakdown voltage of 1148 V and an ultra-low reverse leakage current of 1 μA/cm², maintaining stable operation even at 150 °C. Furthermore, they developed enhancement-mode vertical multi-fin transistors that realize a normally-off characteristic through dual-gate geometric confinement, eliminating the need for a p-type layer. These results provide new technological pathways and solutions for β-Ga₂O₃ power devices.

      References:
      [1] GF Guo, et al. Kilovolt-Class β-Ga₂O₃ Multi-Fin-Channel Diodes with Ohmic-Contact Anode [C], IEEE 37th International Symposium on Power Semiconductor Devices and ICs. Kumamoto, Japan, 2025, 609-612.

      [2] ZL Zou, et al. Over 1.3 kV β-Ga₂O₃ Vertical UMOSFET With High Concentration of N-Ion Implantation and Activation Annealing Temperature [J]. IEEE Transactions on Electron Devices, 2025, 72(5): 2461-2466.

      [3] YJ Ma, et al. 702.3 A·cm^-2/10.4 mΩ·cm² β-Ga₂O₃ U-Shape Trench Gate MOSFET With N-Ion Implantation [J].  IEEE Electron Device Letters, 2023, 44(3): 384-387.

Expert's Message

      “The development of semiconductor materials and devices is not achieved overnight—it is the result of countless experiments, accumulation, and exploration. The bright future of the ultra-wide bandgap semiconductor Gallium Oxide requires joint efforts, collaborative innovation, and the overcoming of challenges by colleagues across all sectors. Wishing continued growth for the Alliance and a bright future for Gallium Oxide!”