Recent progress in GaN-on-Si HEMT

With the benefits of low-loss conduction, high-frequency switching, and high-temperature operation, wide bandgap GaN heterojunction power devices are attractive candidates for next-generation energy-efficient and compact power conversion systems [1-5] including household appliances, photovoltaic inverters, data centers, motor drives, and so on. Compared with mainstream Si power devices, GaN heterojunction power devices are capable of delivering substantially lower ON resistance (R_ON) for the same voltage rating [6]. Such superiority originates from the fundamental material properties including high breakdown strength of GaN (10 times higher than Si), and high density (∼10₁₃cm⁻²) of two-dimensional electron gas (2DEG) with high electron mobility (∼2000 cm²/Vs) in GaN-based heterostructures. Lower R_ONleads to reduced conduction loss and higher power conversion efficiency, while high switching frequency brings the benefit of smaller passives and compact systems. Both the higher conversion efficiency and high-temperature operating capability result in reduced burden of thermal management, and enable simpler/low-cost cooling solutions.