First principles study of Schottky barriers at Ga₂O₃(100)/metal interfaces

A low Schottky barrier height (SBH) of metal-semiconductor contact is essential for achieving high performance electronic devices. Based on first principles calculations, we have comprehensively investigated the interfacial properties of β-Ga₂O₃ (100) with different metals including Mg, Ni, Cu, Pd and Pt. SBHs have been calculated via layered partial density of states (PDOS) and validated by visual wavefunctions. The results surprisingly show that Mg contact possesses the lowest SBH of 0.23 eV, while other SBHs range from 1.06 eV for Ni, 1.17 eV for Pd and 1.27 eV for Cu to 1.39 eV for Pt. This shows that SBHs of β-Ga₂O₃ are not fully dependent on metal work functions due to a Fermi level pinning effect. The tunneling barrier was also calculated via electrostatic potential with a 72.85% tunneling probability of the Mg/Ga₂O₃ interface. The present study will provide an insight into characteristics of Ga₂O₃/metal interfaces and give guidance for metal choice for Ga₂O₃ electronic devices.