A novel AlN/β-Ga2O3 high electron mobility transistor with 2 kV and 600 GHz operation

Abstract In this work, the material characteristics of AlN and Ga 2 O 3 have been exploited to develop a high-performance, AlN/Ga 2 O 3 heterostructure semiconductor device to handle high-power and RF/microwave electronics applications of today’s requirement. AlN is a highly polarized ultra-wide bandgap semiconductor with a bandgap of 6.2 eV and excellent thermal conductivity. Conversely, β-Ga 2 O 3 , with a bandgap of 4.9 eV, is recognized as a stable ultra-wide bandgap semiconductor that is particularly well-suited for power electronics applications. However, it faces limitations such as low thermal conductivity, difficulties in achieving p-type doping, and a high density of bulk defects. However, the potential advantages of AlN and challenges of β-Ga 2 O 3 can be combined by growing thin epitaxial layer of AlN over β-Ga 2 O 3 to achieve high performance power electronic devices. The high 2DEG density (1.395 × 10 14 cm −2 ) at the heterointerface of AlN/β-Ga 2 O 3 and DC and RF characteristics up to 2 kV show the high-voltage and high-power handling capability of the device and 600 GHz cut-off frequency makes it suitable for RF/microwave applications. Unlike previous studies that report isolated performance metrics, our work presents a comprehensive analysis of barrier thickness tuning (10–100 nm), correlating it with DC, RF, and 2DEG characteristics. This provides deeper insight into optimization strategies for AlN/β-Ga₂O₃ HEMT design—a novel contribution to the current body of knowledge.