[21a-P7-1~10] 6.6 Probe Microscopy

[21a-P7-5] Ga/MgAl₂O₄(111) surface structure studied by atomic force microscopy

Nishimura Keiya¹, 〇Arifumi Okada¹, Yoshimura Masamichi², Kadono Kohei¹ (1.Kyoto Inst. Tech., 2.Toyota Tech. Inst.)

Keywords:atomic force microscopy,oxide surface,heteroepitaxial growth

MgAl₂O₄(111) is known as growth substrate of various nitrides and oxides. In the present study, we investigate the surface nanostructure formed by Ga deposition on MgAl₂O₄(111). The MgAl₂O₄ specimen was cut and annealed in air and introduced to an UHV chamber with Si or SiC heater. In some experiments, the specimen was treated by H₂SO₄ + H₃PO₄ mixture. After cleaning procedure in UHV, Ga was deposited on the MgAl₂O₄ surface using a home-made evaporator. The sample surface was observed by atomic force microscopy. We employed dynamic force microscope (DFM) mode before introduction to UHV, and noncontact atomic force microscope (NCAFM) mode in UHV. In both modes, we used Si cantilevers. After Ga deposition, we found the periodic pattern of contrast different from the bare surface. The pattern formation suggests the formation of layer structure of Ga or oxidized Ga on the surface.