Phase Stabilized MOCVD Growth of β-Ga2O3 Using SiOx on c-Plane Sapphire and AlN/Sapphire Template

The growth of monoclinic phase-pure gallium oxide (beta-Ga2O3) layers by metal-organic chemical vapor deposition on c-plane sapphire and aluminum nitride (AlN) templates using silicon-oxygen bonding (SiOx) as a phase stabilizer is reported. The beta-Ga2O3 layers are grown using triethylgallium, oxygen, and silane for gallium, oxygen, and silicon precursors, respectively, at 700 degrees C, with and without silane flow in the process. The samples grown on sapphire with SiOx phase stabilization show a notable change from samples without phase stabilization in the roughness and resistivity, from 16.2 to 4.2 nm and from 85.82 to 135.64 Omega cm, respectively. X-ray diffraction reveals a pure-monoclinic phase, and Raman spatial mapping exhibits higher tensile strain in the films in the presence of SiOx. The beta-Ga2O3 layers grown on an AlN template, using the same processes as for sapphire, show an excellent epitaxial relationship between beta-Ga2O3 and AlN and have a significant change in beta-Ga2O3 surface morphology.