Electrical Performance and Deep-Level Trap Characterization of p-CuGaO₂/β-Ga₂O₃ Heterojunctions for Power Electronics

The development of β-Ga₂O₃-based power devices is hindered by the absence of effective p-type doping, limiting the realization of high-performance bipolar devices. In this study, we investigate the electrical characteristics and deep-level trap states of p-CuGaO₂/β-Ga₂O₃ heterojunction (HJ), offering a promising alternative for power electronics. Electrical characterization of the p-CuGaO₂/β-Ga₂O₃ HJ reveals a reduced V_on and lower R_on compared to a Pt/β-Ga₂O₃ SBD. Notably, the HJ exhibits a maximum breakdown voltage of 1.054 kV. Analysis of the interface state density (N_SS) demonstrates a significant reduction in N_SS at the Pt/β-Ga₂O₃ interface due to the p-CuGaO₂ interlayer. DLTS was employed to identify and distinguish majority carrier traps in both the SBD and HJ structures. In the SBD, dominant electron trap levels were observed at E_C-0.757 eV (1.5 × 10¹² cm^-3) and E_C-1.332 eV (2.6 × 10¹³ cm^-3). The HJ exhibited trap levels at E_C-0.268 eV (8.6 × 10¹¹ cm^-3), E_C-0.857 eV (2.1 × 10¹² cm^-3), and E_C-2.169 eV (3.3 × 10¹³ cm^-3). The observed modulation of trap characteristics through p-CuGaO₂ integration offers promising avenues for optimizing β-Ga₂O₃ power device performance and reliability for power electronics applications.