【Member News】The research group of Associate Professor Lu Xing and Professor Wang Gang at Sun Yat-sen University has made important progress in the field of wide band gap Gallium Oxide semiconductor power devices

      The research group of Associate Professor Lu Xing and Professor Wang Gang from the College of Electronic and Information Engineering (College of Microelectronics) of Sun Yat-sen University has made a breakthrough in the field of wide band gap Gallium Oxide semiconductor power devices. Based on the hetero-epitaxy high-quality ε-phase Gallium Oxide thin film materials independently developed by the research group, field-effect transistor devices with low on-resistance and high breakdown voltage have been successfully developed. A new technical scheme for realizing low cost and high performance Gallium Oxide power electronics is proposed. The results are presented in the form of "Heteroepitaxial ε-Ga₂O₃ MOSFETs on a 4-inch Sapphire Substrate with a Power Figure of Merit of 0.29 GW/cm² ” The title was selected for the 36th International Symposium on Power Semiconductor Devices and ICs (ISPSD). ISPSD is the most influential and largest top-level international academic conference in the field of power devices, and also the premier conference for technical discussion in the field of power semiconductor devices and power integrated circuits. It has always been a stage for domestic and international industry and academia to compete for important results. The first author of the paper is Zeng Deke, a master's student in the research group, and Associate Professor Lu Xing is the corresponding author. The work was strongly supported by the State Key Laboratory of Optoelectronic Materials and Technology and the Experimental Teaching Center of Electronic and Information Engineering at Sun Yat-sen University.

      Semiconductor power devices are used to realize the efficient conversion and control of electric energy, and have wide application value in many fields such as power transmission, industrial control, transportation, satellite communication, national defense and consumer electronics. Gallium Oxide, as the next generation of wide-gap semiconductor materials after Gallium Nitride and Silicon Carbide, has a wider band-gap and a higher breakdown field strength, and is one of the important research directions in the field of power devices. Gallium Oxide has five different phase, α, β, γ, δ and ε, of which β-phase Gallium Oxide is favored because of its best thermal stability, homogeneous substrate and homogeneous epitaxy technology. The low thermal conductivity and high cost of β phase Gallium Oxide substrate are the main problems limiting its development. ε phase Gallium Oxide (also known as κ phase Gallium Oxide by researchers) is the second stable phase of Gallium Oxide, which can be grown on a mature commercial substrate with large size, low cost and high thermal conductivity through heterogeneous epitaxy technology, and is expected to solve the existing β phase Gallium Oxide power devices faced with two major pain points of poor heat dissipation and high cost. The research group adopted the self-developed metal-organic chemical vapor phase deposition (MOCVD) equipment and Gallium Oxide heteroepitaxy growth technology to achieve the preparation of high-quality ε Gallium Oxide films on Sapphire, Silicon, and Silicon Carbide substrates (FIG. a). The accepted paper successfully fabricated a heterogeneous epitaxial ε phase Gallium Oxide field-effect transistor with a breakdown voltage of up to 2.85kV based on a 4-inch sapphire substrate, achieving a power optimization value of 0.29GW /cm² (FIG. b). This work improves the performance of low-cost heteroepitaxial ε phase Gallium Oxide devices to the same level as homoepitaxial β phase Gallium Oxide devices, verifies the application potential of heteroepitaxial Gallium Oxide in the field of power devices, and points out a new direction for the development of Gallium Oxide power devices.

Figure a ε phase Gallium Oxide heteroepitaxial wafer based on a 4-inch sapphire substrate. Performance comparison of b heteroepitaxial ε phase Gallium Oxide field-effect transistor with reported Gallium Oxide transistor devices

      In recent years, the research group is committed to the research and development of a new generation of wide band gap semiconductor material "Gallium Oxide" and equipment development, focusing on power electronics, radio frequency filtering, nuclear radiation detection and other major national demand areas, and continue to produce high-level results. It has published many papers in authoritative journals such as Advanced Science, IEEE Electron Device Letters, and IEEE Transactions on Electron Devices. The team has the ability to independently develop the whole industry chain of Gallium Oxide semiconductor epitaxial growth equipment, materials and chips, and will continue to promote the development and industrialization of wide band gap semiconductor technology in China.