We investigated surface atoms of LiGaO_2 (001) substrate with a single domain structure by CAICISS and found that the atoms of easily etched surface are oxygen and those of hardly etched one are metal(Li,Ga). This relationship is well explained by the surface bonding model of ZnO proposed by Mariano. GaN thin film grew only on the metal surface of LiGaO_2 (001) substrate.
