【World Express】FLOSFIA Successfully developed the world's first corundum gallium oxide SBD with ampere grade and 1700V withstand voltage level

      This time, FLOSFIA used its own unique MistDry^® method, successfully developed the world's first ampere grade, 1700V withstand voltage grade GaO^® SBD, which is made of high quality film. The development promises to drive not only high performance of power electronics, but also to significant energy conservation and miniaturization in areas such as electric vehicles (EVs) and power systems. By giving full play to the advantages of gallium oxide in high current, high voltage and low on resistance, the practical application of GaO^® power semiconductor is expected to promote the realization of semiconductor ecology.

Development points of this study

      FLOSFIA will reduce the three environmental loads caused by semiconductors (energy, process, materials), called the "semiconductor ecological^®", and take it as the ideal purpose. FLOSFIA aims to promote the new power semiconductor material, gallium oxide (Ga₂O₃), developed by Kyoto University. In order to achieve semiconductor ecological^®, the most effective method is to fully realize the potential of gallium oxide material to achieve the energy saving performance,which only gallium oxide holds. FLOSFIA believes that the practical realization of ultra-low loss, ultra-high voltage withstand and high current GaO^® power semiconductor is the key equipment for decarbonization society and electrification, which is indispensable (Figure 1).

Figure 1: Position relationship of α-Ga₂O₃ compared with other semiconductor materials

Results of this study

      By its unique MistDry^® method, FLOSFIA prepared a thick film of high quality α-Ga₂O₃ (α-gallium oxide) film, with an electrode size of 0.96mm and a vertical structure. After optimized process and terminal structure, the device is confirmed to work normally at ampere level 1700V (Figure 2, Figure 3).

Figure 2: (a) cross-sectional structure of SBD (b) microscope photograph

Figure 3: Forward and reverse characteristics of the SBD used this time

Future expectations

      So far, through the empirical prototype of SBD,  FLOSFIA has achieved the world's leading characteristic ON resistance value (86% lower than the marketed SiC),  shipment of SBD sample with 600V / 1200V voltage withstand, and the preparation of the parent factory at Kyoto University, leading the practical use of gallium oxide power semiconductor. Corundum gallium oxide (α-Ga₂O₃) by FLOSFIA  is expected to cover a wide range of areas, from small and medium capacity such as household vehicles and electric vehicles to very large capacity power system collaboration equipment, which are expected to be used. The ampere grade 1700V GaO^® SBD in this study will be developed as FLOSFIA's "GaO^®" series of future devices. With the advantage of gallium oxide, it realized the 1 kA class 20 kV voltage withstand. As a ultra-high voltage withstand and high current power semiconductor, it aims to be applied to small power-saving electric aircraft and other mobile equipment inverter and power conversion device, and to realize "power converter overall miniaturization and low cost" breakthrough through the GaO^® power device.