【Device Papers】Unveiling GaN/α-Ga₂O₃ interface contact barrier modulation via post-deposition annealing: DFT insights

      Researchers from the China Jiliang University have published a dissertation titled "Unveiling GaN/α-Ga₂O₃ interface contact barrier modulation via post-deposition annealing: DFT insights" in Surfaces and Interfaces.

Abstract

      Post-deposition annealing (PDA) offers promising potential strategy of modulating the complex electrical transport properties of heterostructure interfaces, enabling the rational design for next-generation power electronics. Herein, we employed density functional theory calculations to reveal the effect of PDA on the GaN/α-Ga₂O₃ interfacial contact barrier in oxygen (O₂) or nitrogen (N₂) atmospheres. Our simulations reveal that optimized interfacial configurations with 4N and 7O atoms effectively suppress Ga dangling bond-induced trap states. However, oxygen-rich conditions introduce O- and N-related trap states near the valence band maximum (VBM), while nitrogen over incorporation generates N dangling bond defects. Introducing highly electronegative interfacial atoms into GaN/α-Ga₂O₃ interface leads to charge transfer and interfacial dipole formation, modulating electronic states and electrostatic potential. The adhesion strength and orbital overlap of interfacial atoms influence the potential barrier width, modulating the tunneling probability. We elucidate how interfacial barrier height (ΔT = 2.89 eV in 7O system), barrier width (W_TB = 0.7 eV in 7O system) and effective mass (m_e = 0.36 m₀ in 7O system) cooperatively modulate the tunneling probability. These findings demonstrate that PDA in various atmospheres improves heterostructure quality and modulates transport, facilitating the development of high-performance electronic devices.

DOI：

https://doi.org/10.1016/j.surfin.2025.107146