【Epitaxy Papers】Different Growth Modes of Si Doped Ga₂O₃ Films on Sapphire Substrates via Atomic Layer Deposition

      Researchers from the Xi’an University of Posts & Telecommunications have published a dissertation titled "Different Growth Modes of Si Doped Ga₂O₃ Films on Sapphire Substrates via Atomic Layer Deposition" in Journal of Alloys and Compounds.

Abstract

      As an ultrawide-band-gap semiconductor, Ga₂O₃ performs good application prospect in the power devices and solar-blind photodetectors. Doping is the necessary technology to regulate the electrical conductivity of semiconductors whereas the doped growth mode by atomic layer deposition (ALD) technique is specific due to the layer-by-layer growth mode. In this paper, Si-doped Ga₂O₃ films are prepared on sapphire substrates through ALD method for the first time. Different ALD doping modes including traditional GaOSiO and unique Ga(Si)O are both adopted. Elemental analysis reveals that the Si content of Ga(Si)O sample is little less than that of 0.5 % doped GaOSiO sample. The structural characteristics demonstrate that Ga₂O₃ films exhibit a highly preferred (-201) orientation of β-phase polycrystals whereas the crystal quality is degraded along with increasing the Si dopants. Current-voltage measurements indicate that the best electrical properties of Si-doped Ga₂O₃ films are six orders of magnitude better than that of undoped Ga₂O₃ films. The atomic structures of Si-doped bulk and layered Ga₂O₃ are both constructed to simulate the Ga(Si)O and GaOSiO samples respectively and then, the deformation extent and charge transfer around the dopants are revealed clearly using first-principles calculations. The results are beneficial for the applications of Ga₂O₃-based microelectronic devices.

DOI：

https://doi.org/10.1016/j.jallcom.2025.185863