LONG RECTANGULAR ISLANDS OF BETA-GA2O3 ON COGA(001) - STUDIED BY ELECTRON-ENERGY-LOSS SPECTROSCOPY AND SCANNING-TUNNELING-MICROSCOPY

At 700 K, the oxidation with 1 L O-2 of CoGa(001) was investigated by means of high-resolution electron energy loss spectroscopy (EELS), low -energy electron diffraction, Auger electron spectroscopy, and scannin g tunneling microscopy (STM). Oxidation with 1 L O-2 at 700 K leads to the formation of long, rectangular islands of beta-Ga2O3 oriented in the [100] and [010] directions of the substrate. EEL spectra of the is lands of beta-Ga2O3 show intense Fuchs-Kliewer (FK) modes at 305, 455, 645, End 780 cm(-1). The beta-Ga2O3 islands are well ordered and show a (2x1) structure with two domains, oriented perpendicular to each ot her. The two-dimensional lattice parameters of beta-Ga2O3 are determin ed to be a = 2.8 +/- 0.1 Angstrom and b = 5.8 +/- 0.1 Angstrom. (C) 19 98 American Institute of Physics.