Ta-doped epitaxial β-Ga2O3 films deposited on SrTiO3(100) substrates by MOCVD

Abstract In this work, we successfully prepared epitaxial β-Ga2O3 films with different Ta doping concentrations on SrTiO3(100) substrates. XPS measurement indicated that Ta mainly existed in the β-Ga2O3 lattice as +5 valence state, and the actual doping concentration of the Ta element were determined. XRD and TEM results proved the obtained films were high quality β-Ga2O3 single crystal films, and the epitaxial relationship between the film and substrate was β-Ga2O3(100)//SrTiO3(100) with β-Ga2O3 [001]//SrTiO3 . The film with 0.2% Ta doping concentration presented the highest Hall mobility of 11.9 cm2 V−1 s−1, whereas the lowest resistivity was 68.8 Ω cm when the Ta concentration is 1.0%. By controlling the Ta concentration, the carrier concentration of the β-Ga2O3 films could be effectively regulated in the range of 4.15 × 1015–1.12 × 1017 cm−3. The average transmittances of the films in the visible light region exceeded 95%.