ADSORPTION OF SB ON GAAS(111)B STUDIED BY PHOTOEMISSION AND LOW-ENERGY-ELECTRON DIFFRACTION

The surface structures resulting from the deposition of Sb on the GaAs (111)B-(2 x 2) surface at room temperature followed by annealing, have been studied by high-resolution soft X-ray photoemission (SXPS) and l ow energy electron diffraction (LEED). For depositions at room tempera ture with no subsequent anneal and for annealing temperatures up to 30 0 degrees C, Sb islands are formed between which the As trimer-based ( ? x 2) substrate reconstruction of the clean GaAs surface is observed. Annealing to temperatures between 350 and 475 degrees C leads to the creation of Sb chain pairs coexisting with regions of Sb trimers. At 5 00 degrees C an ordered surface is produced, associated with Sb trimer s and an As vacancy.