Epitaxial growth of β-Ga2O3 on SrTiO3 (001) and SrTiO3-buffered Si (001) substrates by plasma-assisted molecular beam epitaxy

Thin Ga2O3 films were deposited by plasma-assisted molecular beam epitaxy on SrTiO3 (001) and SrTiO3-buffered Si (001) substrates. Examination using reflection-high-energy electron diffraction, x-ray diffraction, and transmission electron microscopy shows a consistent picture of (100)- and (1¯12)-oriented β-Ga2O3 grains. The structural alignments are β-Ga2O3[010] || STO ⟨110⟩ and β-Ga2O3 [021] || STO ⟨100⟩, respectively, each with four in-plane rotational domain variants. Successful integration of epitaxial β-Ga2O3 with Si could enable major opportunities for monolithically integrated Ga2O3 technology by serving as a high-quality seed layer for further epitaxial growth.