BILAYER GROWTH PERIOD OSCILLATION OF THE SB-2 REACTIVITY DURING MOLECULAR-BEAM EPITAXY OF ALSB(001)

We report oscillations in Sb, reactivity with the growth surface durin g layer-by-layer deposition of AlSb (001) by molecular beam epitaxy. R eal-time measurements of the Sb desorption rate using line-of-sight ma ss spectrometry, in parallel with reflection high-energy electron diff raction specular beam intensity meaurements, suggest that this behavio r results from the periodic variation of the surface step density as t hese steps act as preferential adsorption sites for antimony. This is further supported by computer simulations that examine the surface ste p density as a function of bilayer coverage. (C) 1997 American Institu te of Physics. [S0003-6951(97)03250-6].