The semiconductor industry is rapidly advancing to enhance energy efficiency, shifting power semiconductors from traditional silicon to next-generation wide bandgap materials like gallium nitride (GaN). Gallium nitride-based devices are characterized by their low on-resistance, high breakdown field, and superior electron mobility, enabling high-speed operation and significantly lower power loss compared to silicon. This efficiency gain is substantial; replacing conventional silicon devices with gallium nitride could yield approximately a ten percent reduction in power consumption in demanding applications such as data centers, base stations, and electric vehicles. However, the mass production of high-performance gallium nitride devices has historically been hampered by the difficulty and high cost of manufacturing large-diameter, high-quality bulk gallium nitride substrates, which typically exhibit very low dislocation densities (for example, less than one thousand per square centimeter). Recent technological breakthroughs, often supported by collaborations with organizations like NEDO, are overcoming this challenge. Innovations center on advanced crystal growth methods, such as the Sodium Flux method, to produce large-diameter gallium nitride single-crystal substrates (for example, 100 millimeters and scaling towards 150 millimeters). Building on this foundation, highly unique epitaxial growth techniques, including pressurized atomic layer growth, are employed to ensure exceptional flatness, composition uniformity, and precise doping control on the substrate. This combination of large, high-quality substrates and specialized epitaxial growth is the critical factor in realizing low-loss, high-power gallium nitride electronic devices, with projections indicating manufacturing costs could be reduced by a factor of ten compared to conventional methods. The successful commercialization and mass adoption of these cost-effective, high-efficiency gallium nitride power semiconductors will be fundamental to achieving global energy conservation goals and accelerating the transition to a low-carbon society.
