TIME-RESOLVED CORE-LEVEL PHOTOELECTRON-SPECTROSCOPY ON SB-TERMINATED GAAS(001) UNDER SB SUPPLY CONTROL AT GROWTH TEMPERATURE

The Sb desorption process from Sb-terminated GaAs(001) substrates has been analysed by time-resolved core-level photoelectron spectroscopy t o investigate the influence of the substrate on the desorption. From t he time dependence of the Ga 3d intensity, and the spectrum changes of Ga 3d and Sb 4d under Sb Bur and during Sb desorption, three series o f time constants for Sb desorption were found and activation energies of 2.5 eV and 1.1 eV were obtained for two of the desorption series. S pectrum analysis clarified that Sb double layers lie on the surface un der Sb flux exposure and that Sb atoms corresponding to activation ene rgies of 2.5 and 1.1 eV desorb from the topmost site of the Sb double layers. This is the same in the case of GaSb (001) substrate without t he activation energy and shows that the bonding strength between the S b atoms of the topmost layer site and the second layer site depends on the substrate materials. (C) 1998 Elsevier Science B.V.