The process of Sb adsorption onto Si(0 0 1)-In(4 x 3) surface phase has been studied using scanning tunneling microscopy (STM). reflection high-energy electron diffraction (RHEED) and Auger electron spectroscopy (AES) techniques. Above 400 degreesC, Sb tends to destroy the initial In-induced phase and terminate the surface forming Sb/Si(0 0 1) interface. Between 400 and about 200 degreesC, however, the decomposition of In-induced reconstruction becomes partial; removing of In atoms from In-Si bonds results in the relaxation of substrate atoms to the sequence of dimer rows separated by 4a(0) which is also destroyed by further Sb adsorption. Below 200 degreesC, the (4 x 1) structure remains intact against Sb deposition. In this case, In and Sb atoms form disordered layer mediated by the corrugation of (4 x 1) structure. (C) 2003 Elsevier Science B.V. All rights reserved.