【International Papers】p-CuGaO₂/β-Ga₂O₃ interfaces: A high-throughput approach for interface prediction and generation for power device applications

      Researchers from the Sejong University have published a dissertation titled "p-CuGaO₂/β-Ga₂O₃ interfaces: A high-throughput approach for interface prediction and generation for power device applications" in Materials Today Advances.

Abstract

      This study integrates a p-type copper gallium oxide (p-CuGaO₂) interlayer to enhance the performance of β-Ga₂O₃-based power devices, addressing challenges in achieving reliable p-type doping. The p-CuGaO₂ interlayer is expected to improve breakdown voltage (BV) and reduce leakage current, increasing device efficiency and reliability under high-temperature conditions. The heterojunction (HJ) system of β-Ga₂O₃ and p-CuGaO₂ is investigated using density functional theory (DFT) via the Vienna Ab initio Simulation Package (VASP) and experimental methods, focusing on the β-Ga₂O₃ (001)/p-CuGaO₂ (006) interface. Binding energy, electron localization, charge density difference, and electrostatic potential drop are analyzed, identifying Configuration-1 as the optimal configuration due to its high binding energy and favorable structural properties. Annealing temperature impacts the microstructure, stoichiometry, optical, electrical, and transport properties of p-CuGaO₂/β-Ga₂O₃ HJs. Electrical measurements reveal reduced turn-on voltage (V_on), on-resistance (R_on), and leakage currents, with the highest BV of 1.62 kV achieved at 800 °C compared to Pt/β-Ga₂O₃ Schottky barrier diode (SBD). The interface state density (N_SS) is evaluated using the high-low frequency approach. Silvaco TCAD simulations explore breakdown mechanisms, demonstrating the potential of p-CuGaO₂ for β-Ga₂O₃ HJ power devices. These findings support the development and manufacture of robust β-Ga₂O₃ HJ power devices.

Highlights

      The p-CuGaO₂(006)/β-Ga₂O₃ (001) interface models with four heterostructures were investigated using the first principles based on DFT studies.

      The p-CuGaO₂/β-Ga₂O₃HJ annealed at 800 °C exhibits superior electrical characteristics including as compared to the as-deposited, 400 °C-annealed, and 600 °C-annealed samples.

      The p-CuGaO₂/β-Ga₂O₃HJs demonstrated their potential for high-temperature operation by achieving the highest BV of 1.62 kV at 800 °C.

      Silvaco TCAD simulations explore breakdown mechanisms, demonstrating the potential of p-CuGaO₂/β-Ga₂O₃HJ power devices.

      The annealing process at 800 °C resulted in p-CuGaO₂/β-Ga₂O₃HJs with excellent electrical properties and high quality, demonstrating their considerable potential for high-temperature applications.