Epitaxial growth of gallium oxide films on c-cut sapphire substrate

The nature of the crystalline phase present in gallium oxide films grown by pulsed-laser deposition on c-cut sapphire substrate has been studied. Amorphous, polycrystalline or epitaxial gallium oxide films can be obtained depending upon the oxygen pressure during the growth in the 400-500 degrees C temperature range. Detailed pole figure measurements on epitaxial films demonstrate that the monoclinic beta-Ga2O3 phase grows epitaxially on c-cut sapphire substrates at T = 500 degrees C under a 10(-5) mbar oxygen pressure. Two distinct textures were evidenced, i.e., the (201) and (101) planes of the monoclinic beta-Ga2O3 phase being parallel to the c-cut sapphire substrates. The corresponding epitaxial relationships were determined and interpreted in the frame of the domain matching epitaxy. The differences in the two textures were correlated to the various atomic configurations in the (201) and (101) planes of the monoclinic beta-Ga2O3 phase. (C) 2015 Elsevier B.V. All rights reserved.