XPS analysis of surface compositional changes in InSb1-xBix (111) due to low-energy Ar+ ion bombardment

Surface compositional changes induced by multistep 0.2-1.0 keV Ar+ ion bomb ardment and subsequent annealing of the single crystalline (111) InSb1-xBix (x congruent to 0.005) epitaxial layer have been studied for the first tim e by X-ray photoelectron spectroscopy (XPS). Application of Ar+ ion beam wi th energy less than or equal to 0.5 keV produced only a slight increase of the Sb/In concentration ratio above 1.0. On the other hand, 1 keV Ar+ bomba rdment was found as the most efficient preparation step which led to the re moval of the surface oxide (identified here as Sb2Ox), severe reduction of surface carbon content, but also to a decrease of Sb/In ratio towards anion deficiency (Sb/In < 0.8). Subsequent short time anneal at 310 degrees C be came sufficient to reach nearly stoichiometric Sb/In ratio in the surface r egion. Final XPS measurements of the sputter-cleaned and annealed surface r evealed that admiring of Bi into InSb does not shift the binding energies o f Sb 3d and In 3d core-levels of the host compound. The binding energy of B i 4f in InSb1-xBix was found to be the same as in elemental Bi. (C) 2000 El sevier Science B.V. All rights reserved.