Ultra-Wide Bandgap β-Ga₂O₃Heterojunction Field-Effect Transistor Using p-Type 4H-SiC Gate for Efficient Thermal Management

The low thermal conductivity and the absence of effective acceptors limit the potential utility of β-Ga2O3 electronics. Herein, to generate an n-channel β-Ga2O3 heterojunction field-effect transistor (FET) with efficient thermal management, n-type β-Ga2O3 as a channel layer was integrated with p-type 4H-SiC as both a gate and a thermal drain via van der Waals interaction. The n-p β-Ga2O3/4H-SiC heterojunction displayed typical rectifying behavior with an ideality factor of 1.4 and a rectification ratio of ∼107. The fabricated β-Ga2O3 heterojunction FET operated in depletion mode with current saturation above the pinch-off voltage, which is consistent with the results of numerical device simulation. Excellent output and transfer characteristics were observed, including no hysteresis, low subthreshold swing (∼114 mV dec-1), and a high output current on/off ratio (∼108). The numerical heat simulation indicated that the integration of β-Ga2O3 with 4H-SiC could greatly lower the peak operating temperature (by >70 °C), thereby improving the long-term reliability and stability of the β-Ga2O3-based electronic devices.